Helicopter Flying Handbook (2019)

12-9

total darkness. A takeoff at night is usually an “altitude over
airspeed” maneuver, meaning a pilot most likely performs
a nearly maximum performance takeoff. This improves the
chances for obstacle clearance and enhances safety.

En Route Procedures

In order to provide a higher margin of safety, it is
recommended that a cruising altitude somewhat higher than
normal be selected. There are three reasons for this. First,
a higher altitude gives more clearance between obstacles,
especially those that are difficult to see at night, such as high-
tension wires and unlighted towers. Second, in the event of
an engine failure, there is more time to set up for a landing
and the greater gliding distance gives more options for a safe
landing. Third, radio reception is improved, particularly if
using radio aids for navigation.

During preflight planning, when possible, it is recommended
that a route of flight be selected that is within reach of an
airport, or any safe landing site. It is also recommended
that pilots fly as close as possible to a populated or lighted
area, such as a highway or town. Not only does this offer
more options in the event of an emergency, but also makes
navigation a lot easier. A course comprised of a series of
slight zigzags to stay close to suitable landing sites and
well-lit areas, only adds a little more time and distance to an
otherwise straight course.

In the event of a forced landing at night, use the same
procedure recommended for day time emergency landings.
If available, turn on the landing light during the final descent
to help in avoiding obstacles along the approach path.

Collision Avoidance at Night

Because the quantity and quality of outside visual references
are greatly reduced, a pilot tends to focus on a single point
or instrument, making him or her less aware of the other
traffic around. Make a special effort to devote enough time
to scan for traffic. As discussed previously in this chapter,
effective scanning is accomplished with a series of short,
regularly spaced eye movements that bring successive
areas of the sky into the central visual field. Contrary to
the 30-degree scan used to view the ground in the case of
scanning for other aircraft, each movement in this case
should not exceed 10 degrees, and each area should be
observed for at least 1 second to enable detection. If the
pilot detects a dimly lit object in a certain direction, the
pilot should not look directly at the object, but scan the area
adjacent to it, called off-center viewing. This will decrease
the chances of fixating on the light and allow focusing more
on the objects (e.g., tower, aircraft, ground lights). Short
stops of a few seconds in duration in each scan will help to
detect the light and its movement. A pilot can determine

another aircraft’s direction of flight by interpreting the
position and anticollision lights, as previously described.
When scanning, pilots should also remember to move their
heads, not just their eyes. Ground obstructions can cover
a considerable amount of sky, and the area can easily be
uncovered by a small head movement.

Approach and Landing

Night approaches and landings do have some advantages over
daytime approaches, as the air is generally smoother, and the
disruptive effects of turbulence and excessive crosswinds are
often absent. However, there are a few special considerations
and techniques that apply to approaches at night. For
example, when landing at night, especially at an unfamiliar
airport, make the approach to a lighted runway and then use
the taxiways to avoid unlighted obstructions or equipment.

Carefully controlled studies have revealed that pilots have a
tendency to make lower approaches at night than during the
day. This is potentially dangerous as there is a greater chance
of hitting an obstacle, such as an overhead wire or fence, that is
difficult to see. It is good practice to make steeper approaches at
night, increasing the probability of clearing obstacles. Monitor
altitude and rate of descent using the altimeter.

Another pilot tendency during night flight is to focus too
much on the landing area and not pay enough attention to
airspeed. If too much airspeed is lost, a vortex ring state
condition may result. Maintain the proper attitude during
the approach, and ensure that you keep some forward
airspeed and movement until close to the ground. Outside
visual references for airspeed and rate of closure may not be
available, especially when landing in an unlit area, so pay
special attention to the airspeed indicator.

Although the landing light is a helpful aid when making
night approaches, there is an inherent disadvantage. The
portion of the landing area illuminated by the landing light
seems higher than the dark area surrounding it. This effect
can cause a pilot to terminate the approach at an altitude that
is too high, which may result in a vortex ring state condition
and a hard landing.

Illusions Leading to Landing Errors

Various surface features and atmospheric conditions
encountered in night landing can create illusions of incorrect
height above and distance from the runway threshold.
Landing errors from these illusions can be prevented by
anticipating them during approaches, conducting an aerial
visual inspection of unfamiliar airports before landing, using
electronic glideslope or VASI systems when available, and
maintaining optimum proficiency in landing procedures.

12-10

Featureless Terrain Illusion

An absence of ground features, as when landing over water,
darkened areas, and terrain made featureless by snow, can
create the illusion that the aircraft is at a higher altitude than
it actually is. The pilot who does not recognize this illusion
will fly a lower approach.

Atmospheric Illusions

Rain on the windscreen can create the illusion of greater
height, and atmospheric haze can create the illusion of being
at a greater distance from the runway. The pilot who does not
recognize these illusions flies a higher approach. Penetration
of fog can create the illusion of pitching up. The pilot who
does not recognize this illusion steepens the approach, often
quite abruptly.

Ground Lighting Illusions

Lights along a straight path can be mistaken for runway
and approach lights. This might include street lights along a
roadside or even the internal lights of a moving train. Another
illusion may occur with very intense runway and approach
lighting. Due to the relative brightness of these lights, the
pilot may perceive them to be closer than they really are.
Assuming that the lights are as close as they appear, the
pilot may attempt an approach that is actually lower than
glideslope. Conversely, the pilot flying over terrain with few
lights may make a lower than normal approach.

Helicopter Night VFR Operations

While ceiling and visibility significantly affect safety in night
VFR operations, lighting conditions also have a profound
effect on safety. Even in conditions in which visibility and
ceiling are determined to be visual meteorological conditions,
the ability to discern unlit or low contrast objects and terrain
at night may be compromised. The ability to discern these
objects and terrain is referred to as the “seeing condition,”
and is related to the amount of natural and man-made
lighting available, and the contrast, reflectivity, and texture
of surface terrain and obstruction features. In order to conduct
operations safely, seeing conditions must be accounted for in
the planning and execution of night VFR operations.

Night VFR seeing conditions can be described by identifying
high lighting conditions and low lighting conditions.

High lighting conditions exist when one of two sets of
conditions are present:

1. The sky cover is less than broken (less than

⁄

cloud

cover), the time is between the local moon rise and
moon set, and the lunar disk is at least 50 percent
illuminated; or

2. The aircraft is operated over surface lighting that, at

least, provides lighting of prominent obstacles, the
identification of terrain features (shorelines, valleys,
hills, mountains, slopes) and a horizontal reference
by which the pilot may control the helicopter. For
example, this surface lighting may be the result of:
a. Extensive cultural lighting (manmade, such as a

built-up area of a city),

b. Significant reflected cultural lighting (such as the

illumination caused by the reflection of a major
metropolitan area’s lighting reflecting off a cloud
ceiling), or

c. Limited cultural lighting combined with a

high level of natural reflectivity of celestial
illumination, such as that provided by a surface
covered by snow or a desert surface.

Low lighting conditions are those that do not meet the high
lighting conditions requirements.

Some areas may be considered a high lighting environment
only in specific circumstances. For example, some surfaces,
such as a forest with limited cultural lighting, normally
have little reflectivity, requiring dependence on significant
moonlight to achieve a high lighting condition. However,
when that same forest is covered with snow, its reflectivity
may support a high lighting condition based only on starlight.
Similarly, a desolate area, with little cultural lighting, such as
a desert, may have such inherent natural reflectivity that it
may be considered a high lighting conditions area regardless
of season, provided the cloud cover does not prevent starlight
from being reflected from the surface. Other surfaces, such
as areas of open water, may never have enough reflectivity or
cultural lighting to ever be characterized as a high lighting area.

Through the accumulation of night flying experience in a
particular area, the pilot develops the ability to determine,
prior to departure, which areas can be considered supporting
high or low lighting conditions. Without that pilot experience,
low lighting considerations should be applied by pilots for
both preflight planning and operations until high lighting
conditions are observed or determined to be regularly
available. Even if the aircraft is certified for day and night
VFR conditions, night flight should only be conducted if
adequate celestial illumination is assured during the entirety
of the flight.

Chapter Summary

Knowledge of the basic anatomy and physiology of the eye
is helpful in the study of helicopter night operations. Adding

13-1

Introduction

The accident rate for helicopters has traditionally been higher
than the accident rate of fixed-wing aircraft, probably due to
the helicopter’s unique capabilities to fly and land in more
diverse situations than fixed-wing aircraft and pilot attempts
to fly the helicopter beyond the limits of his or her abilities or
beyond the capabilities of the helicopter. With no significant
improvement in helicopter accident rates for the last 20 years,
the Federal Aviation Administration (FAA) has joined with
various members of the helicopter community to improve
the safety of helicopter operations.

According to National Transportation Safety Board (NTSB)
statistics, approximately 80 percent of all aviation accidents
are caused by pilot error, the human factor. Many of
these accidents are the result of the failure of instructors
to incorporate single-pilot resource management (SRM)
and risk management into flight training instruction of
aeronautical decision-making (ADM).

SRM is defined as the art of managing all the resources (both
on board the aircraft and from outside sources) available to a
pilot prior to and during flight to ensure a successful flight.
When properly applied, SRM is a key component of ADM.
Additional discussion includes integral topics such as, the
concepts of risk management, workload or task management,
situational awareness, controlled flight into terrain (CFIT)
awareness, and automation management.

Effective Aeronautical

Decision-Making

Chapter 13

13-2

Preflight

Takeoff

Cruise

Approach & Landing

Time

High

Low

Pilot Capabilities

Task Requirements

Figure 13-1.

The pilot has a limited capacity of doing work and handling tasks, meaning there is a point at which the tasking exceeds

the pilot’s capability. When this happens, either tasks are not done properly or some are not done at all.

ADM is all about learning how to gather information, analyze
it, and make decisions. It helps the pilot accurately assess
and manage risk and make accurate and timely decisions.
Although the flight is coordinated by a single person, the
use of available resources, such as air traffic control (ATC)
and flight service stations (FSS)/automated flight service
stations (AFSS), replicates the principles of crew resource
management (CRM) (see page 14-7).

References on SRM and ADM include:

•

FAA-H-8083-2, Risk Management Handbook.

•

Aeronautical Information Manual (AIM).

•

Advisory Circular (AC) 60-22, Aeronautical Decision
Making, which provides background information
about ADM training in the general aviation (GA)
environment.

• FAA-H-8083-25, Pilot’s Handbook of Aeronautical

Knowledge.

Aeronautical Decision-Making (ADM)

Making good choices sounds easy enough. However,
there are a multitude of factors that come into play when
these choices, and subsequent decisions, are made in the
aeronautical world. Many tools are available for pilots to
become more self-aware and assess the options available,
along with the impact of their decision. Yet, with all the
available resources, accident rates are not being reduced. Poor
decisions continue to be made, frequently resulting in lives
being lost and/or aircraft damaged or destroyed. The Risk
Management Handbook discusses ADM and SRM in detail
and should be thoroughly read and understood.

While progress is continually being made in the advancement
of pilot training methods, aircraft equipment and systems, and
services for pilots, accidents still occur. Historically, the term
“pilot error” has been used to describe the causes of these
accidents. Pilot error means an action or decision made by
the pilot was the cause of, or a contributing factor that led to,
the accident. This definition also includes the pilot’s failure to
make a decision or take action. From a broader perspective,
the phrase “human factors related” more aptly describes these
accidents since it is usually not a single decision that leads
to an accident, but a chain of events triggered by a number
of factors.

[Figure 13-1]

The poor judgment chain, sometimes referred to as the
“error chain,” is a term used to describe this concept of
contributing factors in a human factors related accident.
Breaking one link in the chain is often the only event
necessary to change the outcome of the sequence of
events. The following is an example of the type of scenario
illustrating the poor judgment chain.

Scenario

A Helicopter Air Ambulance (HAA) pilot is nearing the end
of his shift when he receives a request for a patient pickup
at a roadside vehicle accident. The pilot has started to feel
the onset of a cold; his thoughts are on getting home and
getting a good night’s sleep. After receiving the request, the
pilot checks the accident location and required flightpath
to determine if he has time to complete the flight to the
scene, then on to the hospital before his shift expires. The
pilot checks the weather and determines that, although
thunderstorms are approaching, the flight can be completed
prior to their arrival.

13-3

The pilot and on-board medical crews depart the home
location and arrive overhead, at the scene of the vehicular
accident. The pilot is not comfortable with the selected
landing area due to tall trees in all quadrants of the confined
area. The pilot searches for a secondary landing area. Unable
to find one nearby, the pilot then returns to the initial landing
area and decides he can make it work.

After successfully landing the aircraft, he is told that there
will be a delay before the patient is loaded because more time
is needed to extricate the patient from the wreckage. Knowing
his shift is nearly over, the pilot begins to feel pressured to
“hurry up” or he will require an extension for his duty day.

After 30 minutes, the patient is loaded, and the pilot ensures
everyone is secure. He notes that the storm is now nearby and
that winds have picked up considerably. The pilot thinks, “No
turning back now, the patient is on board and I’m running out
of time.” The pilot knows he must take off almost vertically
to clear the obstacles and chooses his departure path based
on the observed wind during landing. Moments later, prior to
clearing the obstacles, the aircraft begins an uncontrollable
spin and augers back to the ground, seriously injuring all on
board and destroying the aircraft.

What could the pilot have done differently to break this
error chain? More important—what would you have done
differently? By discussing the events that led to this accident,
you should develop an understanding of how a series of
judgmental errors contributed to the final outcome of this flight.

For example, the pilot’s decision to fly the aircraft knowing
that the effects of an illness were present was the initial
contributing factor. The pilot was aware of his illness, but,
was he aware of the impact of the symptoms—fatigue,
general uneasy feeling due to a slight fever, perhaps?

Next, knowing the shift was about to end, the pilot based his
time required to complete the flight on ideal conditions, and
did not take into consideration the possibility of delays. This
led to a feeling of being time limited.

Even after determining the landing area was unsuitable, the
pilot forced the landing due to time constraints. At any time
during this sequence, the pilot could have aborted the flight
rather than risk crew lives. Instead, the pilot became blinded
by a determination to continue.

After landing, and waiting 30 minutes longer than planned,
the pilot observed the outer effects of the thunderstorm, yet
still attempted to depart. The pilot dispelled any available
options by thinking the only option was to go forward;
however, it would have been safer to discontinue the flight.

Using the same departure path selected under different wind
conditions, the pilot took off and encountered winds that
led to loss of aircraft control. Once again faced with a self-
imposed time constraint, the pilot improperly chose to depart
the confined area. The end result: instead of one patient to
transport by ground (had the pilot aborted the flight at any
point), there were four patients to be transported.

On numerous occasions leading to and during the flight, the
pilot could have made effective decisions that could have
prevented this accident. However, as the chain of events
unfolded, each poor decision left him with fewer options.
Making sound decisions is the key to preventing accidents.
Traditional pilot training emphasizes flying skills, knowledge
of the aircraft, and familiarity with regulations. SRM and
ADM training focus on the decision-making process and on
the factors that affect a pilot’s ability to make effective choices.

Trescott Tips

Max Trescott, Master Certificated Flight Instructor (CFI)
and Master Ground Instructor and winner of the 2008 CFI of
the year, has published numerous safety tips that every pilot
should heed. He believes that the word “probably” should
be purged from our flying vocabulary. Mr. Trescott contends
that “probably” means we’ve done an informal assessment
of the likelihood of an event occurring and have assigned a
probability to it. He believes the term implies that we believe
things are likely to work out, but there’s some reasonable
doubt in our mind. He further explains that if you ever think
that your course of action will “probably work out,” you
need to choose a new option that you know will work out.

Another safety tip details the importance of accumulating
flight hours in one specific airframe type. He explains that
“statistics have shown that accidents are correlated more with
the number of hours of experience a pilot has in a particular
aircraft model and not with his or her total number of flight
hours. Accidents tend to decrease after a pilot accumulates
at least 100 hours of experience in the aircraft he or she is
flying. Thus, when learning to fly, or when transitioning into
a new model, your goal should be to concentrate your flying
hours in that model.” He suggests waiting until you reach 100
hours of experience in one particular model before attempting
a dual rating with another model. In addition, if you only fly
a few hours per year, maximize your safety by concentrating
those hours in just one aircraft model.

The third safety tip that is well worth mentioning is what
Mr. Trescott calls “building experience from the armchair.”
Armchair flying is simply closing your eyes and mentally
practicing exactly what you do in the aircraft. This is an
excellent way to practice making radio calls, departures,
approaches and even visualizing the parts and pieces of the

13-4

aircraft. This type of flying does not cost a dime and will
make you a better prepared and more proficient pilot.

All three of Max Trescott’s safety tips incorporate the ADM
process and emphasize the importance of how safety and
good decision-making is essential to aviation.

The Decision-Making Process

An understanding of the decision-making process provides
a pilot with a foundation for developing ADM skills. Some
situations, such as engine failures, require a pilot to respond
immediately using established procedures with little time
for detailed analysis. Called automatic decision-making,
it is based upon training, experience, and recognition.
Traditionally, pilots have been well trained to react to
emergencies, but are not as well prepared to make decisions
that require a more reflective response when greater analysis
is necessary. They often overlook the phase of decision-
making that is accomplished on the ground: the preflight,
flight planning, performance planning, weather briefing, and
weight/center of gravity configurations. Thorough and proper
completion of these tasks provides increased awareness and
a base of knowledge available to the pilot prior to departure
and once airborne. Typically during a flight, a pilot has time
to examine any changes that occur, gather information, and
assess risk before reaching a decision. The steps leading to
this conclusion constitute the decision-making process.

Defining the Problem

Defining the problem is the first step in the decision-making
process and begins with recognizing that a change has
occurred or that an expected change did not occur. A problem
is perceived first by the senses, then is distinguished through
insight (self-awareness) and experience. Insight, experience,
and objective analysis of all available information are used to
determine the exact nature and severity of the problem. One
critical error that can be made during the decision-making
process is incorrectly defining the problem.

While going through the following example, keep in mind what
errors lead up to the event. What planning could have been
completed prior to departing that may have led to avoiding
this situation? What instruction could the pilot have had
during training that may have better prepared the pilot for this
scenario? Could the pilot have assessed potential problems
based on what the aircraft “felt like” at a hover? All these
factors go into recognizing a change and the timely response.

While doing a hover check after picking up firefighters at
the bottom of a canyon, a pilot realized that she was only
20 pounds under maximum gross weight. What she failed
to realize was that the firefighters had stowed some of their
heaviest gear in the baggage compartment, which shifted

the center of gravity (CG) slightly behind the aft limits.
Since weight and balance had never created any problems
for her in the past, she did not bother to calculate CG and
power required. She did try to estimate it by remembering
the figures from earlier in the morning at the base camp.
At a 5,000-foot density altitude (DA) and maximum gross
weight, the performance charts indicated the helicopter
had plenty of excess power. Unfortunately, the temperature
was 93 °F and the pressure altitude at the pickup point was
6,200 feet (DA = 9,600 feet). Since there was enough power
for the hover check, the pilot decided there was sufficient
power to takeoff.

Even though the helicopter accelerated slowly during the
takeoff, the distance between the helicopter and the ground
continued to increase. However, when the pilot attempted to
establish the best rate of climb speed, the nose tended to pitch
up to a higher-than-normal attitude, and the pilot noticed that
the helicopter was not gaining enough altitude in relation to
the canyon wall approximately 200 yards ahead.

Choosing a Course of Action

After the problem has been identified, a pilot must evaluate
the need to react to it and determine the actions to take to
resolve the situation in the time available. The expected
outcome of each possible action should be considered and
the risks assessed before a pilot decides on a response to
the situation.

The pilot’s first thought was to pull up on the collective and
pull back on the cyclic. After weighing the consequences of
possibly losing rotor revolutions per minute (rpm) and not
being able to maintain the climb rate sufficiently to clear the
canyon wall, which was then only a hundred yards away, she
realized the only course was to try to turn back to the landing
zone on the canyon floor.

Implementing the Decision and Evaluating the

Outcome

Although a decision may be reached and a course of action
implemented, the decision-making process is not complete.
It is important to think ahead and determine how the
decision could affect other phases of the flight. As the flight
progresses, a pilot must continue to evaluate the outcome of
the decision to ensure that it is producing the desired result.

As the pilot made the turn to the downwind, the airspeed
dropped nearly to zero, and the helicopter became very
difficult to control. (At this point, the pilot must increase
airspeed in order to maintain translational lift.) Since the
CG was aft of limits, she needed to apply more forward
cyclic than usual. As she approached the landing zone
with a high rate of descent, she realized that she would

13-5

Situational Awareness

Situational awareness is the accurate perception and understanding of all the factors and conditions

within the four fundamental risk elements (pilot, aircraft, environment, external pressures).

Facilitate development of

ADM is a systematic approach to

the mental process of evaluating

a given set of circumstances and

determining the best course

of action.

Single-Pilot Resource Management

5P Model: Plan, Plane, Pilot, Passengers, Programming

Information

Management

Information management is the

process pilots use to gather

pertinent information from all

appropriate sources.

Automation

Management

Automation management is

the ability to control and

navigate an aircraft by

correctly managing its

automated systems.

Task

Management

Task management is the

process pilots use to manage

the many concurrent tasks

involved in safely flying

an aircraft.

Risk

Management

Risk management is a

decision-making process

designed to identify hazards

systematically, assess the

degree of risk, and determine

the best course of action.

Perceive,

Process,

Perform

to identify, evaluate, and

mitigate hazards related to

3P Model

ilot

ircraft

ironment

xternal Pressures

Incorporates the elements of

These elements combine to create and maintain

Higher-Order Thinking Skills (HOTS)

Aeronautical Decision-Making

Problem-Based Learning

Scenario-Based Training

Learner-Centered Grading

Figure 13-2.

Various models of decision-making are used in problem solving.

be in a potential vortex ring state situation if she tried to
trade airspeed for altitude and lost effective translational
lift (ETL). Therefore, it did not appear that she would be
able to terminate the approach in a hover. The pilot decided
to make the shallowest approach possible and perform a
run-on landing.

Pilots sometimes have trouble not because of deficient basic
skills or system knowledge, but because of faulty decision-
making skills. Although aeronautical decisions may appear
to be simple or routine, each individual decision in aviation
often defines the options available for the next decision the
pilot must make, and the options (good or bad) it provides.

Therefore, a poor decision early in a flight can compromise
the safety of the flight at a later time. It is important to make
appropriate and decisive choices because good decision-
making early in an emergency provide greater latitude for
later options.

Decision-Making Models

The decision-making process normally consists of several
steps before a pilot chooses a course of action. A variety
of structured frameworks for decision-making provide
assistance in organizing the decision process. These models
include but are not limited to the 5P (Plan, Plane, Pilot,
Passengers, Programming), the OODA Loop (Observation,
Orientation, Decision, Action), and the DECIDE (Detect,
Estimate, Choose, Identify, Do, and Evaluate) models.

[Figure 13-2]

All these models and their variations are

discussed in detail in the Pilot’s Handbook of Aeronautical
Knowledge section covering aeronautical decision-making.

Whichever model is used, the pilot learns how to define
the problem, choose a course of action, implement the
decision, and evaluate the outcome. Remember, there is
no one right answer in this process: a pilot analyzes the
situation in light of experience level, personal minimums,
and current physical and mental readiness levels, and then
makes a decision.

13-6

llness—

Do I have any symptoms?

edication

—Have I been taking prescription or

over-the-counter drugs?

tress

—Am I under psychological pressure from

the job? Worried about financial matters, health
problems, or family discord?

lcohol

—Have I been drinking within 8 hours?

Within 24 hours?

atigue

—Am I tired and not adequately rested?

motion

—Am I angry, depressed, or anxious?

I’M SAFE CHECKLIST

Figure 13-3.

I’M SAFE checklist.

Pilot Self-Assessment

The pilot in command (PIC) of an aircraft is directly
responsible for and is the final authority for the operation
of that aircraft. The list of PIC responsibilities is long,
and nothing should be overlooked. To exercise those
responsibilities effectively and make effective decisions
regarding the outcome of a flight, a pilot must have an
understanding of personal limitations. Pilot performance from
planning the flight to execution of the flight is affected by
many factors, such as health, experience, knowledge, skill
level, and attitude.

Exercising good judgment begins prior to taking the controls
of an aircraft. Often, pilots thoroughly check their aircraft
to determine airworthiness, yet do not evaluate their own
fitness for flight. Just as a checklist is used when preflighting
an aircraft, a personal checklist based on such factors as
experience, currency, and comfort level can help determine
if a pilot is prepared for a particular flight. Specifying when
refresher training should be accomplished and designating
weather minimums, which may be higher than those listed in
Title 14 of the Code of Federal Regulations (14 CFR) part 91,
are elements that may be included on a personal checklist. Over
confidence can kill just as fast as inexperience. In addition to a
review of personal limitations, a pilot should use the I’M SAFE
checklist to further evaluate fitness for flight.

[Figure 13-3]

Curiosity: Healthy or Harmful?

The roots of aviation are firmly based on curiosity. Where
would we be today had it not been for the dreams of
Leonardo da Vinci, the Wright Brothers, and Igor Sikorsky?
They all were infatuated with flight, a curiosity that led to
the origins of aviation. The tale of aviation is full of firsts:
first flight, first helicopter, first trans-Atlantic flight, and so
on. But, along the way there were many setbacks, fatalities,
and lessons learned.

Today, we continue to learn and investigate the limits
of aviation. We’ve been to the moon, and soon beyond.
Our curiosity will continue to drive us to search for the
next challenge.

However, curiosity can also have catastrophic consequences.
Despite over 100 years of aviation practice, we still see
accidents that are caused by impaired judgment formed
from curious behavior. Pilots commonly seek to determine
the limits of their ability as well as the limits of the aircraft.
Unfortunately, too often this leads to mishaps with deadly
results. Inquisitive behavior must be harnessed and displayed
within personal and material limits.

Deadly curiosity may not seem as obvious to some as it is to
others. Simple thoughts such as, “Is visibility really as bad
as what the ATIS is reporting?” or “Will the 20-minute fuel
light really indicate only 20 minutes worth of fuel?” can lead
to poor decisions and disastrous outcomes.

Some aviators blatantly violate rules and aircraft limitations
without thinking through the consequences. “What
indications and change in flight characteristics will I see if
I fly this helicopter above its maximum gross weight?” or
“I’ve heard this helicopter can do aerobatic flight. Why is it
prohibited?” are examples of extremely harmful curiosity.
Even more astounding is their ignoring to the fact that the
damage potentially done to the aircraft will probably manifest
later in the aircraft’s life, affecting other crews. Spontaneous
excursions in aviation can be deadly.

Curiosity is natural and promotes learning. Airmen should
abide by established procedures until proper and complete
hazard assessment and risk management can be completed.

The PAVE Checklist

As found in the Pilot’s Handbook of Aeronautical
Knowledge, the FAA has designed a personal minimums
checklist. To help pilots with self-assessment, which in turn
helps mitigate risk, the acronym PAVE divides the risks of
flight into four categories. For each category, think of the
applicability specific to helicopter operations:

•

Pilot (pilot in command)
-

Physical, emotional readiness.

Flight experience, recency, currency, total time
in type.

• Aircraft

Is the helicopter capable of performing the task?

Can it carry the necessary fuel?

13-7

Does it provide adequate power margins for the
task to be accomplished?

Can it carry the weight and remain within CG?

Will there be external loads?

• Environment

- Helicopters are susceptible to the impact of

changing weather conditions.

How will the change in moderating temperatures
and DA affect performance?

- Will controllability be jeopardized by winds,

terrain, and turbulence?

•

External pressures
-

Do not let the notion to accomplish “the mission”
override good judgment and safety.

Many jobs include time lines. How often do we
hear “time is money” or “time is wasting”? Don’t
sacrifice safety for an implied or actual need to
meet the deadline!

- Do not allow yourself to feel pressured by

coworkers, family events, or friends.

Incorporated into preflight planning, the PAVE checklist
provides the pilot with a simple way to remember each
category to examine for risk prior to each flight. Once the
pilot identifies the risks of a flight, he or she needs to decide
whether the risk or combination of risks can be managed
safely and successfully. Remember, the PIC is responsible
for deciding about canceling the flight. If the pilot decides to
continue with the flight, he or she should develop strategies
to mitigate the risks.

One way to control risk is by setting personal minimums
for items in each risk category. Remember, these are limits
unique to an individual pilot’s current level of experience and
proficiency. They should be reevaluated periodically based
upon experience and proficiency.

Single-Pilot Resource Management

Many of the concepts utilized in CRM have been successfully
applied to single-pilot operations which led to the development
of SRM. Defined as the art and science of managing all the
resources (both on board the aircraft and from outside
resources) available to a single pilot (prior to and during
flight), SRM helps to ensure the successful outcome of the
flight. As mentioned earlier, this includes risk management,
situational awareness (SA), and CFIT awareness.

SRM training helps the pilot maintain SA by managing
automation, associated control, and navigation tasks. This

enables the pilot to accurately assess hazards, manage
resulting risk potential, and make good decisions.

To make informed decisions during flight operations, a pilot
must be aware of the resources found both inside and outside
the cockpit. Since useful tools and sources of information
may not always be readily apparent, learning to recognize
these resources is an essential part of SRM training. The pilot
must not only identify the available resources, but he or she
must also assess whether sufficient time is available to use
a particular one, and the impact its use will have upon the
safety of the flight.

If a pilot is flying alone into a confined area with no wind
sock or access to a current wind report, should that pilot pick
an approach path based on the direction of wind information
received from an earlier weather brief? Making an approach
into a confined area with a tailwind is a bad decision and can
be avoided. Prior to landing, the pilot should use outside
resources such a smoke, trees, and water on a pond to help
him or her accurately determine which direction the winds are
coming from. Pilots should never leave flying up to chance
and hope for the best. Many accidents could and should be
avoided by simply using the resources, internal and external
that are available.

Internal resources are found in the cockpit during flight. Since
some of the most valuable internal resources are ingenuity,
knowledge, and skill, a pilot can expand cockpit resources
immensely by improving these capabilities. This can be
accomplished by frequently reviewing flight information
publications, such as 14 CFR and the AIM, as well as by
pursuing additional training.

No other internal resource is more important than the pilot’s
own ability to control the situation, thereby controlling the
aircraft. Helicopter pilots quickly learn that it is not possible
to hover, single pilot, and pick up the checklist, a chart, or
publication without endangering themselves, the aircraft, or
those nearby.

Checklists are essential cockpit resources used to verify
the aircraft instruments and systems are checked, set, and
operating properly. They also ensure proper procedures
are performed if there is a system malfunction or inflight
emergency. Pilots at all levels of experience refer to
checklists. The more advanced the aircraft is, the more crucial
checklists are.

Therefore, have a plan on how to use the checklist (and other
necessary publications) before you begin the flight. Always
control the helicopter first. When hovering in an airport
environment, the pilot can always land the aircraft to access

13-8

ROBINSON R22

OTORCRAFT

LIGHT

ANUAL

Figure 13-4.

Rotorcraft Flying Manual (RFM).

the checklist or a publication, or have a passenger assist with
holding items. There is nothing more unsettling than being in
flight and not having a well thought-out plan for managing
the necessary documents and data. This lack of planning
often leads to confusion, distractions and aircraft mishaps.

Another way to avoid a potentially complex and confusing
situation is to remove yourself from the situation. The
following is an example of how proper resource management
and removal from a situation are vital to safe flight.

A single pilot is conducting a helicopter cross-country flight.
He frequently goes to and is familiar with the final destination
airport. Weather is briefed to be well above the minimum
weather needed, but with isolated thunderstorms possible.
For the pilot, this is a routine run-of-the-mill flight. He has
done this many times before and has memorized the route,
checkpoints, frequencies, fuel required and knows exactly
what to expect.

However, once within 30 miles of the destination airport
the pilot observes that weather is deteriorating, and a
thunderstorm is nearby. The pilot assesses the situation and
determines the best course of action is to reroute to another
airport. The closest airport is an airport within Class C
airspace. At this point, the pilot realizes the publications with
the required alternate airport information are in the back of
the helicopter out of reach. Now what?

The pilot continues toward the alternate airport while
using the onboard equipment to access the information.
He struggles to obtain the information because he or she
is not thoroughly familiar with its operation. Finally, the
information is acquired and the pilot dials in the appropriate
alternate airfield information. Upon initial contact ARTCC
(Air Route Traffic Control Center) notifies the pilot that he
has entered the airspace without the required clearance; in
effect the pilot has violated airspace regulations.

Things have gone from bad to worse for him. When did the
trouble begin for this pilot and what options were available?
Without a doubt, problems began during the planning phase, as
the necessary resources were placed in the back of the aircraft,
unavailable to the pilot during flight. Additional training with
the available automated systems installed on the helicopter
would have expedited access to the necessary information.
What if they hadn’t been installed or were inoperative?

Next, a poor decision to continue towards the Class C airspace
was made. The pilot could have turned away from the Class
C airspace, removing himself from the situation until the
frequencies were entered and contact established. Remember,
when possible, choose an option that gives more time to

determine a course of action. Proper resource management
could have negated this airspace violation.

The example also demonstrates the need to have a thorough
understanding of all the equipment and systems in the
aircraft. As is often the case, the technology available today
is seldom used to its maximum capability. It is necessary to
become as familiar as possible with this equipment to utilize
all resources fully. For example, advanced navigation and
autopilot systems are valuable resources. However, if pilots
do not fully understand how to use this equipment, or they
rely on it so much they become complacent, the equipment
can become a detriment to safe flight.

Another internal resource is the Rotorcraft Flight Manual
(RFM).

[Figure 13-4]

The RFM:

•

Must be on board the aircraft.

•

Is indispensable for accurate flight planning.

•

Plays a vital role in the resolution of inflight equipment
malfunctions.

Other valuable flight deck resources include current
aeronautical charts and publications, such as the Airport/
Facility Directory (A/FD).

As stated previously, passengers can also be a valuable
resource. Passengers can help watch for traffic and may be
able to provide information in an irregular situation, especially
if they are familiar with flying. Crew briefs to passengers
should always include some basic helicopter terminology. For
example, explain that in the event you ask them if you are clear
to hover to the right, their response should be either “yes, you
are clear to hover to the right” or “no you are not clear.” A
simple yes or no answer can be ambiguous. A strange smell
or sound may alert a passenger to a potential problem. As PIC,
a pilot should brief passengers before the flight to make sure
that they are comfortable voicing any concerns.

13-9

To maintain situational awareness, an accurate

perception must be attained of how the pilot, helicopter,

environment, and operation combine to affect the flight.

Situation

RISK ELEMENTS

Environment

Aircraft

Pilot

External Pressures

Factors such as weather and

airport conditions must be

examined.

The helicopter performance,

limitations, equipment, and

airworthiness must be deter-

mined.

The purpose of the flight is a

factor that influences the pilot’s

decision on undertaking or

continuing the flight.

The pilot’s fitness to fly must

be evaluated, including com-

petency in the helicopter,

currency, and flight experience.

Figure 13-5.

Risk elements to evaluate in decision-making.

Instruction that integrates Single-Pilot Resource Management
into flight training teaches aspiring pilots how to be more
aware of potential risks in flying, how to identify those
risks clearly, and how to manage them successfully. The
importance of integrating available resources and learning
effective SRM skills cannot be overemphasized. Ignoring
safety issues can have fatal results.

Risk Management

Risk management is a formalized way of dealing with
hazards. It is the logical process of weighing the potential
cost of risks from hazards against the possible benefits of
allowing those risks from hazards to stand unmitigated. It
is a decision-making process designed to identify hazards
systematically, assess the degree of risk, and determine the
best course of action. Once risks are identified, they must be
assessed. The risk assessment determines the degree of risk
(negligible, low, medium, or high) and whether the degree
of risk is worth the outcome of the planned activity. If the
degree of risk is “acceptable,” the planned activity may
then be undertaken. Once the planned activity is started,
consideration must then be given whether to continue. Pilots
must have preplanned, viable alternatives available in the
event the original flight cannot be accomplished as planned.

Two defining elements of risk management are hazard and risk.

• A hazard is a present condition, event, object, or

circumstance that could lead to or contribute to an
unplanned or undesired event, such as an accident.
It is a source of danger. For example, binding in the
antitorque pedals represents a hazard.

• Risk is the future impact of a hazard that is not

controlled or eliminated. It is the possibility of loss
or injury. The level of risk is measured by the number
of people or resources affected (exposure), the extent
of possible loss (severity), and the likelihood of
loss (probability).

A hazard can be a real or perceived condition, event, or
circumstance that a pilot encounters. Learning how to identify
hazards, assess the degree of risk they pose, and determine the
best course of action is an important element of a safe flight.

Four Risk Elements

During each flight, decisions must be made regarding events
that involve interactions between the four risk elements—the
PIC, the aircraft, the environment, and the operation. The
decision-making process involves an evaluation of each of
these risk elements to achieve an accurate perception of the
flight situation.

[Figure 13-5]

One of the most important decisions that a PIC must make is
the go/no-go decision. Evaluating each of these risk elements
can help a pilot decide whether a flight should be conducted
or continued. In the following situations, the four risk
elements and how they affect decision-making are evaluated.

Pilot—A pilot must continually make decisions about
personal competency, condition of health, mental and
emotional state, level of fatigue, and many other variables.
A situation to consider: a pilot is called early in the morning
to make a long flight. With only a few hours of sleep and
congestion that indicates the possible onset of a cold, is
that pilot safe to fly?

Aircraft—A pilot frequently bases decisions to fly on

13-10

personal evaluations of the aircraft, such as its powerplant,
performance, equipment, fuel state, or airworthiness. A
situation to consider: en route to an oil rig an hour’s flight
from shore, having just passed the shoreline, the pilot notices
the oil temperature at the high end of the caution range.
Should the pilot continue out to sea or return to the nearest
suitable heliport/airport?

Environment—This encompasses many elements unrelated
to the pilot or aircraft. It can include such factors as weather,
ATC, navigational aids (NAVAID), terrain, takeoff and
landing areas, and surrounding obstacles. Weather is one
element that can change drastically over time and distance.
A situation to consider: a pilot is ferrying a helicopter cross-
country and encounters unexpected low clouds and rain in an
area of rising terrain. Does the pilot try to stay under them
and scud run, or turn around, stay in the clear, and obtain
current weather information?

External Pressures—The interaction between the pilot,
the aircraft, and the environment is greatly influenced by
the purpose of each flight operation. A pilot must evaluate
the three previous areas to decide on the desirability of
undertaking or continuing the flight as planned. It is worth
asking why the flight is being made, how critical it is to
maintain the schedule, and if the trip is worth the risks. A
situation to consider: a pilot is tasked to take some technicians
into rugged mountains for a routine survey in marginal
weather. Would it be preferable to wait for better conditions
to ensure a safe flight? How would the priorities change if a
pilot were tasked to search for cross-country skiers who had
become lost in deep snow and radioed for help?

Assessing Risk

It is important for a pilot to learn how to assess risk. Before a
pilot can begin to assess risk, he or she must first perceive the
hazard and attendant risk(s). In aviation, experience, training,
and education help a pilot learn how to spot hazards quickly
and accurately. During flight training, the instructor should
point out the hazards and attendant risks to help the student
pilot learn to recognize them.

Once a hazard is identified, determining the probability
and severity of an accident (level of risk associated with it)
becomes the next step. For example, the hazard of binding
in the antitorque pedals poses a risk only if the helicopter is
flown. If the binding leads to a loss of directional control,
the risk is high that it could cause catastrophic damage
to the helicopter and the passengers. The pilot learns to
identify hazards and how to deal with them when they are
incorporated into the training program.

Every flight has hazards and some level of risk associated

with it. It is critical that pilots be able to:

• Differentiate, in advance, between a low-risk flight

and a high-risk flight.

•

Establish a review process and develop risk mitigation
strategies to address flights throughout that range.

Examining NTSB reports and other accident research can
help a pilot to assess risk more effectively. For example,
the accident rate decreases by nearly 50 percent once a
pilot obtains 100 hours and continues to decrease until the
1,000-hour level. The data suggest that for the first 500
hours, pilots flying visual flight rules (VFR) at night should
establish higher personal limitations than are required by the
regulations and, if applicable, apply instrument flying skills
in this environment.

Individuals training to be helicopter pilots should remember
that the helicopter accident rate is 30 percent higher than the
accident rate for fixed-wing aircraft. While many factors
contribute to this, students must recognize the small margin
of error that exists for helicopter pilots in making critical
decisions. In helicopters, certain emergency actions require
immediate action by the pilot. In the event of an engine
malfunction, failure to immediately lower the collective
results in rotor decay and failed autorotation. Fixed wing
pilots may have slightly more time to react and establish
a controllable descent. According to the General Aviation
(GA) Joint Steering Committee, the leading causes of
accidents in GA are CFIT (see p.14-15), weather, runway
incursions, pilot decision-making, and loss of control.
These causes are referred to as pilot-error, or human factors
related, accidents. CFIT, runway incursions, and loss of
control type accidents typically occur when the pilot makes
a series of bad judgments, which leads to these events. For
example, when the pilot has not adequately planned the
flight and the pilot subsequently fails to maintain adequate
situational awareness to avoid the terrain, a CFIT accident
occurs.

While the reasons for individual helicopter incidents vary,
it can be argued that it is the helicopter’s flight mode and
operational complexity that directly contributes to each
incident. By nature of its purpose, a helicopter usually
flies closer to terrain than does a fixed-wing aircraft.
Subsequently, minimal time exists to avoid CFIT, weather
related, or loss of control type incidents that require quick
and accurate assessments. Fixed-wing aircraft normally fly
at higher altitudes and are flown from prepared surface to
prepared surface. Helicopters are often operated in smaller,
confined area-type environments and require continuous
pilot control. Helicopter pilots must be aware of what rotor
wash can do when landing to a dusty area or prior to starting
where loose debris may come in contact with the rotor blades.

13-11

Aeronautical

Decision-

Making

(Perceive)

(Perform)

(Process)

Figure 13-6.

3P Model.

Often, the loss of control occurs when the pilot exceeds
design or established operating standards, and the resulting
situation exceeds pilot capability to handle it successfully.
The FAA generally characterizes these occurrences as
resulting from poor judgment. Likewise, most weather-
related accidents are not a result of the weather per se, but
of a failure of the pilot to avoid a weather phenomenon for
which the aircraft is not equipped, or the pilot is not trained
to handle. That is, the pilot decides to fly or to continues
into conditions beyond pilot capability, an action commonly
considered to be demonstrating bad judgment.

It cannot be emphasized enough that the helicopter’s unique
capabilities come with increased risk. Since most helicopter
operations are conducted by a single pilot, the workload is
increased greatly. Low-level maneuvering flight (a catch-
all category for different types of flying close to terrain or
obstacles, such as power line patrol, wildlife control, crop
dusting, air taxiing, and maneuvering for landing after an
instrument approach), is one of the largest single categories
of fatal accidents.

Fatal accidents that occur during approach often happen at
night or in instrument flight rules (IFR) conditions. Takeoff/
initial climb accidents are frequently due to the pilot’s lack
of awareness of the effects of density altitude on aircraft
performance or other improper takeoff planning that results
in loss of control during or shortly after takeoff. One of the
most lethal types of GA flying is attempting VFR flight into
instrument meteorological conditions (IMC). Accidents
involving poor weather decision-making account for about
4 percent of the total accidents but 14 percent of the fatal
mishaps. While weather forecast information has been
gradually improving, weather should remain a high priority
for every pilot assessing risk.

Using the 3P Model to Form Good Safety Habits

As discussed in the Pilot’s Handbook of Aeronautical
Knowledge, the Perceive, Process, Perform (3P) model helps
a pilot assess and manage risk effectively in the real world.

[Figure 13-6]

To use this model, the pilot will:

•

Perceive hazards

•

Process level of risk

•

Perform risk management

Let’s put this to use through a common scenario, involving a
common task, such as a confined area approach. As is often
the case, the continuous loop consists of several elements;
each element must be addressed through the 3P process.

A utility helicopter pilot receives the task of flying four
passengers into a remote area for a hunting expedition. The
passengers have picked the location where they would like
to be dropped off based on the likelihood of wildlife being
in the area. The area has steep, rugged terrain in a series of
valleys and canyons leading up to large mountains.

Upon arrival at the location, the pilot locates a somewhat
large confined area near the base of one of the mountains.
The pilot begins the 3P process by quickly noting (or
perceiving) the hazards that affect the approach, landing,
and takeoff. Through thorough assessment the pilot takes
into consideration:

•

Current aircraft weight/power available,

•

Required approach angle to clear the trees for landing
in the confined area,

•

Wind direction and velocity,

• Limited approach and departure paths (due to

constricting terrain),

• Escape routes should the approach need to be

terminated prior to landing,

•

Possible hazards, such as wires or structures either
around the landing site or inside of the confined area,
and

•

The condition of the terrain at the landing site. Mud,
dust, and snow can be extreme hazards if the pilot is not
properly trained to land in those particular conditions.

13-12

The pilot reviews the 3P process for each hazard. The pilot
has perceived the risk associated for each of the bullets listed
above. Now, the pilot assesses the risk level of each and what
to do to manage or mitigate the risk.

The aircraft weight/power risk is assessed as low. While
performing power checks, the pilot verified adequate out of
ground effect (OGE) power exists. The pilot is also aware
that, in this scenario, the departure DA (6,500 feet) is greater
than the arrival location DA (6,000 feet) and that several
hundred pounds of fuel have been burned off en route.
Furthermore, once the passengers have disembarked, more
power will be available for departure.

The pilot estimates that the highest obstacles along the
approach path are 70–80 feet in height. With the size of the
confined area, a normal approach angle can be maintained
to clear these obstacles, giving this a low risk level. To further
mitigate this risk the pilot has selected mental checkpoints
along the approach path that will serve as go/no-go points
should the pilot feel any assessed parameter is being exceeded.

Wind direction and velocity are assessed as a medium risk
because (for this scenario) the direction of the wind is slightly
offset from the chosen approach path, creating a 15–20°
crosswind with a steady 10-knot wind. The pilot also takes
into consideration that, due to the terrain, the wind direction
and velocity may change during the approach. The pilot’s
experience and awareness of the complexity of mountain flow
wind provide a management tool for risk reduction.

From an approach and departure standpoint, the risk is
assessed to be medium. There is only one viable approach
and departure path. Given the size of the confined area
and the wind direction, the approach and departure path is
deemed acceptable.

The pilot assigns a medium risk level to the selection of an
escape route. The pilot is aware of the constricting terrain on
either side. Although adequate area exists for maneuvering,
the pilot realizes there are physical boundaries and that
they can affect the options available should the pilot need to
conduct a go-around or abort the approach. Again, the pilot
uses mental checkpoints to ensure an early decision is made
to conduct a go-around, if needed. The selected go-around
or escape route will be in line with the selected approach/
departure path and generally into the wind.

As you may have noticed, one identified hazard and its
correlating risk management action may have subsequent
impact on other factors. This demonstrates the need for
continuous assessment and evaluation of the impact of chosen
courses of action.

The 3P model offers three good reasons for its use. First, it
is fairly simple to remember. Second, it offers a structured,
efficient, and systematic way to identify hazards, assess risk,
and implement effective risk controls. Third, practicing risk
management needs to be as automatic as basic aircraft control.
As is true for other flying skills, risk management thinking
habits are best developed through repetition and consistent
adherence to specific procedures.

Once the pilot completes the 3P decision process and selects
a course of action, the process begins anew as the set of
circumstances brought about by the selected course of action
requires new analysis. Thus, the decision-making process is
a continuous loop of perceiving, processing, and performing.

Workload or Task Management

One component of SRM is workload or task management.
Research shows that humans have a limited capacity for
information. Once information flow exceeds the person’s
ability to mentally process the information, any additional
information becomes unattended or displaces other tasks
and information already being processed. Once this situation
occurs, only two alternatives exist: shed the unimportant
tasks or perform all tasks at a less than optimal level. Like
an overloaded electrical circuit, either the consumption must
be reduced or a circuit failure is experienced.

Effective workload management ensures essential operations
are accomplished by planning and then placing them in
a sequence that avoids work overload. As a pilot gains
experience, he or she learns to recognize future workload
requirements and can prepare for high workload periods
during times of low workload.

Reviewing the appropriate chart and setting radio frequencies
well in advance of need help reduce workload as a flight
nears the airport. In addition, a pilot should listen to
Automatic Terminal Information Service (ATIS), Automated
Surface Observing System (ASOS), or Automated Weather
Observing System (AWOS), if available, and then monitor
the tower frequency or Common Traffic Advisory Frequency
(CTAF) to get a good idea of what traffic conditions to
expect. Checklists should be performed well in advance so
there is time to focus on traffic and ATC instructions. These
procedures are especially important prior to entering a high-
density traffic area, such as Class B airspace.

To manage workload, items should be prioritized. For
example, during any situation, and especially in an
emergency, a pilot should remember the phrase “aviate,
navigate, and communicate.” This means that the first

13-13

thing a pilot should do is make sure the helicopter is under
control, then begin flying to an acceptable landing area.
Only after the first two items are assured should a pilot try
to communicate with anyone.

Another important part of managing workload is recognizing
a work overload situation. The first effect of high workload
is that a pilot begins to work faster. As workload increases,
attention cannot be devoted to several tasks at one time, and
a pilot may begin to focus on one item. When a pilot becomes
task saturated, there is no awareness of additional inputs from
various sources, so decisions may be made on incomplete
information, and the possibility of error increases.

A very good example of this is inadvertent IMC. Once entering
into bad weather, work overload can occur immediately.
Mentally, the pilot must transition from flying outside of the
aircraft to flying inside the aircraft. Losing all visual references
can cause sensory overload and the ability to think rationally
can be lost. Instead of trusting the aircraft’s instruments, pilots
may try to hang onto the few visual references that they have,
and forget all about all other factors surrounding them. Instead
of slowing the helicopter down they increase airspeed. This
can be caused by an oculogravic illusion. This type of illusion
occurs when an aircraft accelerates and decelerates. Inertia
from linear accelerations and decelerations cause the otolith
organ to sense a nose-high or nose-low attitude. Pilots falsely
perceive that the aircraft is in a nose-high attitude. Therefore,
pilots increase airspeed. Pilots can also be looking down for
visual references and forget about the hazards in front of
them. Finally, since the pilots are not looking at the flight
instruments, the aircraft is not level. All of this can be avoided
by proper training and proper planning. If going inadvertent
IMC is your only course of action, pilots must commit to it
and fly the helicopter using only the flight instruments and not
trying to follow the few visual references they have.

When a work overload situation exists, a pilot needs to:

• Stop,
• Think,
•

Slow down, and then

• Prioritize.

It is important for a pilot to understand how to decrease
workload by:

•

Placing a situation in the proper perspective,

•

Remaining calm, and

•

Thinking rationally.

These key elements reduce stress and increase the pilot’s
ability to fly safely. They depend upon the experience,

discipline, and training that each safe flight earns. It is
important to understand options available to decrease
workload. For example, setting a radio frequency may be
delegated to another pilot or to a passenger, freeing the pilot
to perform higher-priority tasks.

Situational Awareness

In addition to learning to make good aeronautical decisions,
and learning to manage risk and flight workload, SA is an
important element of ADM. SA is the accurate perception
and understanding of all the factors and conditions within
the four fundamental risk elements (PAVE) that affect safety
before, during, and after the flight. SA involves being aware
of what is happening around you, in order to understand how
information, events, and your own actions will impact your
goals and objectives, both now and in the near future. Lacking
SA or having inadequate SA has been identified as one of
the primary factors in accidents attributed to human error.

SA in a helicopter can be quickly lost. Understanding the
significance and impact of each risk factor independently
and cumulatively aid in safe flight operations. It is possible,
and all too likely, that we forget flying while at work. Our
occupation, or work, may be conducting long line operations,
maneuvering around city obstacles to allow a film crew
access to news events, spraying crops, ferrying passengers
or picking up a patient to be flown to a hospital. In each case
we are flying a helicopter. The moment we fail to account for
the aircraft systems, the environment, other aircraft, hazards,
and ourselves, we lose SA.

To maintain SA, all of the skills involved in SRM are
used. For example, an accurate perception of pilot fitness
can be achieved through self-assessment and recognition
of hazardous attitudes. A clear assessment of the status of
navigation equipment can be obtained through workload
management, while establishing a productive relationship
with ATC can be accomplished by effective resource use.

Obstacles to Maintaining Situational Awareness

What distractions interfere with our focus or train of thought?
There are many. A few examples pertinent to aviation, and
helicopters specifically, follow.

Fatigue, frequently associated with pilot error, is a threat to
aviation safety because it impairs alertness and performance.

[Figure 13-7]

The term is used to describe a range of

experiences from sleepy or tired to exhausted. Two major
physiological phenomena create fatigue: circadian rhythm
disruption and sleep loss.

Many helicopter jobs require scheduling flexibility,
frequently affecting the body’s circadian rhythm. You

13-14

Warning Signs of Fatigue

Vision going in and out of focus

Head bobbing involuntarily

Persistent yawning

Spotty short-term memory

Wandering or poorly organized thoughts

Missed or erroneous performance of routine procedures

Degradation of control accuracy

Long naps (3–4 hours*) can restore alertness
for 12–15 hours.
Short power naps (10–30 minutes*)
can restore alertness for 3–4 hours.
Eat high-protein meals.

Drink plenty of ﬂuids, especially water.
Rotate ﬂight tasks and converse with other

crew members or passengers.

Keep the ﬂight deck temperature cool.
Move/stretch in the seat, and periodically
get up to walk around the aircraft, if possible.

* Allow 15–20 minutes after awakening to become fully

alert before assuming aircrew duties.

Countermeasures

Figure 13-7. Warning signs of

fatigue

according to the FAA Civil Aerospace Medical Institute (CAMI)

Figure 13-8. Countermeasures to fatigue according to the FAA
Civil Aerospace Medical Institute (CAMI)

Since complacency seems to creep into our routine without
notice, ask what has changed. The minor changes that go
unnoticed can be associated with the four fundamental risks
we previously discussed: pilot, aircraft, environment, and
external pressures.

As a pilot, am I still using checklists or have I become reliant
on memory to complete my checks? Do I check (Notices to
Airmen) NOTAMs before every flight or only when I think
it is necessary? And the aircraft: did I feel that vibration
before or is it new? Was there a log book entry for it? If so,

may be flying a day flight Monday and then at night on
Tuesday. Your awareness of how your body and mind
react to this variation in schedule is vital to safety. This
disruptive pattern may result in degradation of attention
and concentration, impaired coordination, and decreased
ability to communicate.

Physical fatigue results from sleep loss, exercise, or physical
work. Factors such as stress and prolonged performance of
cognitive work result in mental fatigue. Consecutive days of
flying the maximum allowable flight time can fatigue a pilot,
mentally and physically. It is important to take breaks within
the workday, as well as days off when possible. When you find
yourself in this situation, take an objective, honest assessment
of your state of mind. If necessary, use rest periods to allow
rejuvenation of the mind and body.

[Figure 13-8]

Fatigue also occurs under circumstances in which there is
anticipation of flight followed by inactivity. For instance,
a pilot is given a task requiring a specific takeoff time. In
anticipation of the flight, the pilot’s adrenaline kicks in and
SA is elevated. After a delay (weather, maintenance, or any
other unforeseen delay), the pilot feels a letdown, in effect,
becoming fatigued. Then, upon resuming the flight, the pilot
does not have that same level of attention.

Complacency presents another obstacle to maintaining
SA. Defined as overconfidence from repeated experience
with a specific activity, complacency has been implicated
as a contributing factor in numerous aviation accidents
and incidents. When activities become routine, a pilot may
have a tendency to relax and not put as much effort into
performance. Like fatigue, complacency reduces a pilot’s
effectiveness on the flight deck. However, complacency is
more difficult to recognize than fatigue, since everything
seems to be progressing smoothly.

13-15

has it been checked?

Complacent acceptance of common weather patterns can
have huge impacts on safety. The forecast was for clearing
after the rain shower, but what was the dew-point spread?
The winds are greater than forecast. Will this create reduced
visibility in dusty, snowy areas or exceed wind limitations?

While conducting crop spraying, a new agent is used.
Does that change the weight? Does that change the flight
profile and, if so, what new hazards might be encountered?
When things are going smoothly, it is time to heighten your
awareness and become more attentive to your flight activities.

Advanced avionics have created a high degree of redundancy
and dependability in modern aircraft systems, which can
promote complacency and inattention. Routine flight
operations may lead to a sense of complacency, which can
threaten flight safety by reducing SA.

Loss of SA can be caused by a minor distraction that diverts
the pilot’s attention from monitoring the instruments or
scanning outside the aircraft. For example, a gauge that is
not reading correctly is a minor problem, but it can cause an
accident if the pilot diverts attention to the perceived problem
and neglects to control the aircraft properly.

Operational Pitfalls

There are numerous common behavioral traps that can
ensnare the unwary pilot. Pilots, particularly those with
considerable experience, try to complete a flight as planned,
please passengers, and meet schedules. This basic drive to
achieve can have an adverse effect on safety and can impose
an unrealistic assessment of piloting skills under stressful
conditions. These tendencies ultimately may bring about
practices that are dangerous and sometimes illegal and may
lead to a mishap. Pilots develop awareness and learn to avoid
many of these operational pitfalls through effective SRM
training.

[Figure 13-9]

Controlled Flight Into Terrain (CFIT)

Awareness

An emergency medical services (EMS) helicopter departed
for a night flight to transport an 11-day-old infant patient
from one hospital to another. No record was found indicating
the pilot obtained a weather briefing before departure. The
pilot had a choice of taking either a direct route that crossed
a remote area of rugged mountainous terrain with maximum
ground elevations of about 9,000 feet or a route that was
about 10 minutes longer and followed an interstate highway
with maximum ground elevations of about 6,000 feet. Radar
data, which show about 4 minutes of the helicopter’s flight
before coverage was lost due to mountainous terrain, are

consistent with the flight following the direct route.

A search was initiated about 4 hours after the helicopter did
not arrive at the destination hospital, and the wreckage was
located the following morning. Physical evidence observed
at the accident site indicated that the helicopter was in level
flight at impact and was consistent with CFIT. [Figure 13-10]

CFIT is a type of accident that continues to be a major safety
concern, while at the same time difficult to explain because
it involves a pilot controlling an airworthy aircraft that is
flown into terrain (water or obstacles) with inadequate pilot
awareness of the impending disaster.

One constant in CFIT accidents is that outside visibility is
limited, or the accident occurs at night and the terrain is not
seen easily until just prior to impact. Another commonality
among CFIT accidents is lack of SA. This includes not only
horizontal awareness, and knowing where the helicopter is
over the ground, but also vertical awareness.

Training, planning, and preparation are a pilot’s best defenses
for avoiding CFIT accidents. For example, take some time
before takeoff to become familiar with the proposed flight and
the terrain. Avoidance of CFIT begins before the helicopter
departs the home location. Proper planning, including applied
risk mitigation must occur before the aircraft is even started.
Thorough assessment of terrain, visibility, pilot experience
and available contingencies must be conducted. If necessary,
delay or postpone the flight while on the ground. The decision
to abort the flight is much easier to make in the planning room
than in the air. In case conditions deteriorate once in flight.
Have contingency options available.

While many CFIT accidents and incidents occur during
nonprecision approaches and landings, great measures have
been taken to improve instrument training, equipment and
procedures. For the qualified pilot, instrument flight should
not be avoided, but rather, trained as a viable option for safely
recovering the aircraft. Like any other training, frequent
instrument training builds confidence and reassurance.

Good instrument procedures include studying approach
charts before leaving cruise altitude. Key fixes and airport
elevation must be noted and associated with terrain and
obstacles along the approach path. Pilots should have a good
understanding of both approach and departure design criteria
to understand fully the obstacle clearance margins built into
them. Some pilots have the false belief that ATC provides
obstacle clearance while en route off airways. The pilot is
ultimately responsible for obstacle clearance.

13-16

Operational Pitfalls

Peer Pressure

It would be foolish and unsafe for a new pilot to attempt to compete with an older, more experienced pilot. The only safe competition
should be completing the most safe flights with no one endangered or hurt and the aircraft returned to service. Efficiency comes with
experience and on-the-job training.

Mindset

A pilot should be taught to approach every day as something new.

Get-There-Itis

This disposition impairs pilot judgment through a fixation on the original goal or destination, combined with a disregard for any
alternative course of action.

Duck-Under Syndrome

A pilot may be tempted to arrive at an airport by descending below minimums during an approach. There may be a belief that
there is a built-in margin of error in every approach procedure, or the pilot may not want to admit that the landing cannot be
completed and a missed approach must be initiated.

Scud Running

It is difficult for a pilot to estimate the distance from indistinct forms, such as clouds or fog formation.

Continuing Visual Flight Rules (VFR) Into Instrument Conditions

Spatial disorientation or collision with ground/obstacles may occur when a pilot continues VFR into instrument conditions. This can
be even more dangerous if the pilot is not instrument rated or current.

Getting Behind the Aircraft

This pitfall can be caused by allowing events or the situation to control pilot actions. A constant state of surprise at what happens
next may be exhibited when the pilot is “getting behind” the aircraft.

Loss of Positional or Situational Awareness

In extreme cases of a pilot getting behind the aircraft, a loss of positional or situational awareness may result. The pilot may not
know the aircraft’s geographical location, or may be unable to recognize deteriorating circumstances.

Operating Without Adequate Fuel Reserves

Pilots should use the last of the known fuel to make a safe landing. Bringing fuel to an aircraft is much less inconvenient than
picking up the pieces of a crashed helicopter! Pilots should land prior to whenever their watch, fuel gauge, low-fuel warning system,
or flight planning indicates fuel burnout. They should always be thinking of unforecast winds, richer-than-planned mixtures,
unknown leaks, mis-servicing, and errors in planning. Newer pilots need to be wary of fuselage attitudes in low-fuel situations.
Some helicopters can port air into the fuel system in low-fuel states, causing the engines to quit or surge.

Descent Below the Minimum En Route Altitude

The duck-under syndrome, as mentioned above, can also occur during the en route portion of an IFR flight.

Flying Outside the Envelope

The pilot must understand how to check the charts, understand the results, and fly accordingly.

Neglect of Flight Planning, Preflight Inspections, and Checklists

All pilots and operators must understand the complexity of the helicopter, the amazing number of parts, and why there are service
times associated with certain parts. Pilots should understand material fatigue and maintenance requirements. Helicopters are
unforgiving of disregarded maintenance requirements. Inspections and maintenance are in place for safety: something functioning
improperly can be the first link in the error chain to an accident. In some cases, proper maintenance is a necessary condition for
insurance converage.

Figure 13-9.

Operational pitfalls.

Altitude error is another common cause of CFIT. Cases
of altitude error involve disorientation with respect to the
NAVAID, improper transition on approach, selecting the
wrong NAVAID, or just plain lack of horizontal SA. Today’s
modern aircraft have sophisticated flight directors, autopilots,
autothrottles, and flight management systems. These devices
make significant contributions to the overall safety of flight,

but they are only machines that follow instructions. They
do whatever is asked of them, even if it is wrong. When
commanded, they unerringly follow instructions—sometimes
straight into the ground. The pilot must ensure that both
vertical and horizontal modes are correct and engaged. Cross-
check autopilots constantly.

13-17

Figure 13-10.

Helicopter heading straight for mountain.

When automated flight equipment is not available, great
care must be taken to prepare properly for a night flight.
SRM becomes more challenging under the cover of
darkness, and caution should be exercised when determining
what artificial light source to use inside the aircraft. A light
source that is too bright will blind the pilot from seeing
outside obstacles or rising terrain. Certain colored lenses
bleach out symbols and markings on a map. Conduct this
planning on the ground, in a dark room if necessary, before
the actual flight.

Pilots must be even more conservative with their decision-
making and planning when flying at night. Flying becomes
more difficult due to the degradation of our sensory perception
and the lack of outside references. Beginning with preflight,
looking over the helicopter with a flashlight can cause pilots
to miss even the smallest discrepancy that they would easily
see during the day. For example, failing to remove one or all
of the tie downs and attempting to take off would probably
result in a dynamic rollover accident. Whenever possible,
preflight inspection should always be conducted during the
day or in a lighted hangar. Depth perception is less acute;
therefore, hover height should be increased to avoid contact
with obstacles and hover speed should be reduced. Weather
conditions can be very deceptive and difficult to detect in
flight under night conditions. On a low-illumination night,
it is easy to fly into clouds without realizing it before it is
too late to correct.

Due to the number of recent CFIT night accidents, the NTSB
issued a safety alert in 2008 about avoiding night CFIT
accidents. That alert included the following information:

• Terrain familiarization is critical to safe visual

operations at night. Use sectional charts or other
topographic references to ensure the helicopter will
safely clear terrain and obstructions all along the route.

• When planning a nighttime VFR flight, follow IFR

practices, such as climbing on a known safe course

until well above surrounding terrain. Choose a cruising
altitude that provides terrain separation similar to IFR
flights (2,000 feet above ground level in mountainous
areas and 1,000 feet above the ground in other areas).
Using this technique, known obstacles, such as towers,
will be avoided.

•

When receiving radar services, do not depend on ATC
to warn of terrain hazards. Although controllers try
to warn pilots if they notice a hazardous situation,
they may not always recognize that a particular VFR
aircraft is dangerously close to terrain.

• When ATC issues a heading with an instruction to

“maintain VFR,” be aware that the heading may
not provide adequate terrain clearance. If any doubt
exists about your ability to avoid terrain and obstacles
visually, advise ATC immediately and take action to
reach a safe altitude.

•

For improved night vision, the FAA recommends the
use of supplemental oxygen for flights above 5,000 feet.

•

Obtain as much information about areas in which you
will be flying, and the routes to them, by utilizing
hazard maps and satellite imagery.

• Before flying at night to unfamiliar remote areas or

areas with hazardous terrain, try to arrange a day flight
for familiarization.

• If a pilot flies at night, especially in remote or unlit

areas, consider whether a global positioning system
(GPS)-based terrain awareness unit would improve
the safety of the flight.

Of particular note in the 2008 safety alert is a comment
regarding oxygen use above 5,000 feet. Most helicopters
are neither required nor equipped for supplemental oxygen
use at this altitude. Due to the physiological effect on night
vision of reduced available oxygen at higher elevations, care
should be taken to exercise light discipline. Interior lighting
should be lowered to the lowest possible levels but must allow
adequate illumination of necessary systems and instruments.
This, in turn, allows greater recognition of outside obstacles
and terrain features.

Limited outside visibility is one constant in CFIT accidents.
In the accident cited at the beginning of this section, it
appears the pilot failed to obtain a weather briefing. If the
pilot had obtained one, he would probably have learned
of the cloud cover and light precipitation present along
his planned route of flight. The limited outside visibility
probably caused the CFIT accident, since no evidence was
found of any pre-impact mechanical discrepancies with the
helicopter’s airframe or systems that would have prevented

13-18

normal operation.

Automation Management

Automation management is the control and navigation of an
aircraft by means of the automated systems installed in the
aircraft. One of the most important concepts of automation
management is simply knowing when to use it and when not to.

Ideally, a pilot first learns to perform practical test standard
(PTS) maneuvers and procedures in the aircraft manually,
or hand flying. After successfully demonstrating proficiency
in the basic maneuvers, the pilot is then introduced to the
available automation and/or the autopilot. Obviously, in some
aircraft, not all automated systems may be disengaged for
basic flight. The purpose of basic flight without automation is
to ensure the pilot can hand fly the maneuver when necessary.

Advanced avionics offer multiple levels of automation, from
strictly manual flight to highly automated flight. No one level
of automation is appropriate for all flight situations, but to
avoid potentially dangerous distractions when flying with
advanced avionics, the pilot must know how to manage the
course indicator, the navigation source, and the autopilot.
It is important for a pilot to know the peculiarities of the
particular automated system in use. This ensures the pilot
knows what to expect, how to monitor for proper operation,
and promptly take appropriate action if the system does not
perform as expected.

At the most basic level, managing the autopilot means
knowing at all times which modes are engaged and which
modes are armed to engage. The pilot needs to verify that
armed functions (e.g., navigation tracking or altitude capture)
engage at the appropriate time. Automation management is a
good place to practice the callout technique, especially after
arming the system to make a change in course or altitude.
Callouts are verbalizations of particular flight guidance
automation mode changes. In an attempt to reduce the risk
for mode confusion some operators have required flight
crews to callout all flight guidance automation mode changes
as a means of forcing pilots to monitor the Flight Mode
Annunciator (FMA).

Chapter Summary

This chapter focused on aeronautical decision-making,
which includes SRM training, risk management, workload
or task management, SA, CFIT awareness, and automation
management. Factors affecting a helicopter pilot’s ability to
make safe aeronautical decisions were also discussed. The
importance of learning how to be aware of potential risks in
flying, how to clearly identify those risks, and how to manage
them successfully were also explored.

G-1

Absolute altitude.

The actual distance an object is above

the ground.

Advancing blade.

The blade moving in the same direction as

the helicopter. In helicopters that have counterclockwise main
rotor blade rotation as viewed from above, the advancing
blade is in the right half of the rotor disk area during forward
movement.

Agonic Line.

An isogonic line along which there is no

magnetic variation.

Air density.

The density of the air in terms of mass per unit

volume. Dense air has more molecules per unit volume than
less dense air. The density of air decreases with altitude above
the surface of the earth and with increasing temperature.

Aircraft pitch.

The movement of the aircraft about its lateral,

or pitch, axis. Movement of the cyclic forward or aft causes
the nose of the helicopter to pitch up or down.

Aircraft roll.

The movement of the aircraft about its

longitudinal axis. Movement of the cyclic right or left causes
the helicopter to tilt in that direction.

Airfoil.

Any surface designed to obtain a useful reaction of

lift, or negative lift, as it moves through the air.

Airworthiness Directive.

When an unsafe condition exists

with an aircraft, the FAA issues an Airworthiness Directive
to notify concerned parties of the condition and to describe
the appropriate corrective action.

Altimeter.

An instrument that indicates flight altitude by

sensing pressure changes and displaying altitude in feet or
meters.

Angle of attack.

The angle between the airfoil’s chord line

and the relative wind.

Antitorque pedal.

The pedal used to control the pitch of the

tail rotor or air diffuser in a NOTAR® system.

Glossary

Antitorque rotor.

See tail rotor.

Articulated rotor.

A rotor system in which each of the blades

is connected to the rotor hub in such a way that it is free to
change its pitch angle, and move up and down and fore and
aft in its plane of rotation.

Autopilot.

Those units and components that furnish a means

of automatically controlling the aircraft.

Autorotation.

The condition of flight during which the main

rotor is driven only by aerodynamic forces with no power
from the engine.

Axis of rotation.

The imaginary line about which the rotor

rotates. It is represented by a line drawn through the center
of, and perpendicular to, the tip-path plane.

Basic empty weight.

The weight of the standard helicopter,

operational equipment, unusable fuel, and full operating
fluids, including full engine oil.

Blade coning.

An upward sweep of rotor blades as a result

of lift and centrifugal force.

Blade damper.

A device attached to the drag hinge to restrain

the fore and aft movement of the rotor blade.

Blade feather or feathering.

The rotation of the blade around

the spanwise (pitch change) axis.

Blade flap.

The ability of the rotor blade to move in a vertical

direction. Blades may flap independently or in unison.

Blade grip.

The part of the hub assembly to which the rotor

blades are attached, sometimes referred to as blade forks.

Blade lead or lag.

The fore and aft movement of the blade

in the plane of rotation. It is sometimes called “hunting” or
“dragging.”

G-2

Blade loading.

The load imposed on rotor blades, determined

by dividing the total weight of the helicopter by the combined
area of all the rotor blades.

Blade root.

The part of the blade that attaches to the blade

grip.

Blade span.

The length of a blade from its tip to its root.

Blade stall.

The condition of the rotor blade when it is

operating at an angle of attack greater than the maximum
angle of lift.

Blade tip.

The furthermost part of the blade from the hub

of the rotor.

Blade track.

The relationship of the blade tips in the plane

of rotation. Blades that are in track will move through the
same plane of rotation.

Blade tracking.

The mechanical procedure used to bring the

blades of the rotor into a satisfactory relationship with each
other under dynamic conditions so that all blades rotate on
a common plane.

Blade twist.

The variation in the angle of incidence of a blade

between the root and the tip.

Blowback.

The tendency of the rotor disk to tilt aft in

transition to forward flight as a result of unequal airflow.

Calibrated airspeed (CAS).

Indicated airspeed of an aircraft,

corrected for installation and instrumentation errors.

Center of gravity.

The theoretical point where the entire

weight of the helicopter is considered to be concentrated.

Center of pressure.

The point where the resultant of all the

aerodynamic forces acting on an airfoil intersects the chord.

Centrifugal force.

The apparent force that an object moving

along a circular path exerts on the body constraining the
object and that acts outwardly away from the center of
rotation.

Centripetal force.

The force that attracts a body toward its

axis of rotation. It is opposite centrifugal force.

Chip detector.

A warning device that alerts you to any

abnormal wear in a transmission or engine. It consists of a
magnetic plug located within the transmission. The magnet
attracts any metal particles that have come loose from the
bearings or other transmission parts. Most chip detectors have
warning lights located on the instrument panel that illuminate
when metal particles are picked up.

Chord.

An imaginary straight line between the leading and

trailing edges of an airfoil section.

Chordwise axis.

For semirigid rotors, a term used to describe

the flapping or teetering axis of the rotor.

Coaxial rotor.

A rotor system utilizing two rotors turning

in opposite directions on the same centerline. This system is
used to eliminated the need for a tail rotor.

Collective pitch control.

The control for changing the pitch

of all the rotor blades in the main rotor system equally and
simultaneously and, consequently, the amount of lift or thrust
being generated.

Coning.

See blade coning.

Coriolis effect.

The tendency of a rotor blade to increase or

decrease its velocity in its plane of rotation when the center
of mass moves closer to or farther from the axis of rotation.

Cyclic feathering.

The mechanical change of the angle of

incidence, or pitch, of individual rotor blades, independent
of other blades in the system.

Cyclic pitch control.

The control for changing the pitch of

each rotor blade individually as it rotates through one cycle
to govern the tilt of the rotor disk and, consequently, the
direction and velocity of horizontal movement.

Degraded Visual Environment (DVE).

Any flight

environment of reduced visibility in which situational
awareness of the aircrew or control of the aircraft may
be severely diminished, completely lost, or may not be
maintained as comprehensively as they are during flight
operations within clear or undiminished visibility. DVE
conditions are further categorized into eleven different types:
smoke, smog, clouds, rain, fog, snow, whiteout, night, flat
light, sand, and brownout.

G-3

Delta hinge.

A flapping hinge with an axis skewed so that

the flapping motion introduces a component of feathering that
would result in a restoring force in the flap-wise direction.

Density altitude.

Pressure altitude corrected for nonstandard

temperature variations.

Deviation.

A compass error caused by magnetic disturbances

from the electrical and metal components in the aircraft. The
correction for this error is displayed on a compass correction
card placed near the magnetic compass of the aircraft.

Direct control.

The ability to maneuver a helicopter by tilting

the rotor disk and changing the pitch of the rotor blades.

Direct shaft turbine.

A single-shaft turbine engine in which

the compressor and power section are mounted on a common
driveshaft.

Disk area.

The area swept by the blades of the rotor. It is

a circle with its center at the hub and has a radius of one
blade length.

Disk loading.

The total helicopter weight divided by the

rotor disk area.

Dissymmetry of lift.

The unequal lift across the rotor disk

resulting from the difference in the velocity of air over the
advancing blade half and the velocity of air over the retreating
blade half of the rotor disk area.

Drag.

An aerodynamic force on a body acting parallel and

opposite to relative wind.

Dual rotor.

A rotor system utilizing two main rotors.

Dynamic rollover.

The tendency of a helicopter to continue

rolling when the critical angle is exceeded, if one gear is on
the ground, and the helicopter is pivoting around that point.

Emergency Position Indicator Radio Beacon (ERIPB).

device used to alert search and rescue services in the event
of an emergency by transmitting a coded message on the 406
MHz distress frequency, which is relayed by the Cospas-
Sarsat global satellite system.

Feathering.

The action that changes the pitch angle of

the rotor blades by rotating them around their feathering
(spanwise) axis.

Feathering axis.

The axis about which the pitch angle of a

rotor blade is varied. Sometimes referred to as the spanwise
axis.

Feedback.

The transmittal of forces, which are initiated by

aerodynamic action on rotor blades, to the cockpit controls.

Flapping.

The vertical movement of a blade about a flapping

hinge.

Flapping hinge.

The hinge that permits the rotor blade to

flap and thus balance the lift generated by the advancing and
retreating blades.

Flare.

A maneuver accomplished prior to landing to slow

a helicopter.

Free turbine.

A turboshaft engine with no physical

connection between the compressor and power output shaft.

Freewheeling unit.

A component of the transmission or

power train that automatically disconnects the main rotor
from the engine when the engine stops or slows below the
equivalent rotor rpm.

Fully articulated rotor system.

See articulated rotor system.

Gravity.

See weight.

Gross weight.

The sum of the basic empty weight and

useful load.

Ground effect.

A usually beneficial influence on helicopter

performance that occurs while flying close to the ground. It
results from a reduction in upwash, downwash, and bladetip
vortices, which provide a corresponding decrease in induced
drag.

Ground resonance.

Selfexcited vibration occurring

whenever the frequency of oscillation of the blades about the
lead-lag axis of an articulated rotor becomes the same as the
natural frequency of the fuselage.

Gyroscopic procession.

An inherent quality of rotating

bodies, which causes an applied force to be manifested 90°
in the direction of rotation from the point where the force
is applied.

Human factors.

The study of how people interact with their

environment. In the case of general aviation, it is the study
of how pilot performance is influenced by such issues as the
design of cockpits, the function of the organs of the body, the
effects of emotions, and the interaction and communication
with other participants in the aviation community, such as
other crew members and air traffic control personnel.

G-4

Hunting.

Movement of a blade with respect to the other

blades in the plane of rotation, sometimes called leading or
lagging.

In ground effect (IGE) hover.

Hovering close to the surface

(usually less than one rotor diameter distance above the
surface) under the influence of ground effect.

Induced drag.

That part of the total drag that is created by

the production of lift.

Induced flow.

The component of air flowing vertically

through the rotor system resulting from the production of lift.

Inertia.

The property of matter by which it will remain at rest

or in a state of uniform motion in the same direction unless
acted upon by some external force.

Isogonic line.

Lines on charts that connect points of equal

magnetic variation.

Knot.

A unit of speed equal to one nautical mile per hour.

DMAX

The maximum ratio between total lift (L) and total

drag (D). This point provides the best glide speed. Any
deviation from the best glide speed increases drag and reduces
the distance you can glide.

Lateral vibration.

A vibration in which the movement is

in a lateral direction, such as imbalance of the main rotor.

Lead and lag.

The fore (lead) and aft (lag) movement of the

rotor blade in the plane of rotation.

Licensed empty weight.

Basic empty weight not including

full engine oil, just undrainable oil.

Lift.

One of the four main forces acting on a helicopter. It

acts perpendicular to the relative wind.

Load factor.

The ratio of a specified load weight to the total

weight of the aircraft.

Married needles.

A term used when two hands of an

instrument are superimposed over each other, as on the
engine/rotor tachometer.

Mast.

The component that supports the main rotor.

Mast bumping.

Action of the rotor head striking the mast,

occurring on underslung rotors only.

Navigational aid (NAVAID).

Any visual or electronic

device, airborne or on the surface, that provides point-to-point
guidance information, or position data, to aircraft in flight.

Night.

The time between the end of evening civil twilight

and the beginning of morning civil twilight, as published in
the American Air Almanac.

Normally aspirated engine.

An engine that does not

compensate for decreases in atmospheric pressure through
turbocharging or other means.

One-to-one vibration.

A low frequency vibration having

one beat per revolution of the rotor. This vibration can be
either lateral, vertical, or horizontal.

Out of ground effect (OGE) hover.

Hovering a distance

greater than one disk diameter above the surface. Because
induced drag is greater while hovering out of ground effect,
it takes more power to achieve a hover out of ground effect.

Parasite drag.

The part of total drag created by the form or

shape of helicopter parts.

Payload.

The term used for the combined weight of

passengers, baggage, and cargo.

Pendular action.

The lateral or longitudinal oscillation of

the fuselage due to its suspension from the rotor system.

Pitch angle.

The angle between the chord line of the rotor

blade and the reference plane of the main rotor hub or the
rotor plane of rotation.

Pressure altitude.

The height above the standard pressure

level of 29.92 "Hg. It is obtained by setting 29.92 in the
barometric pressure window and reading the altimeter.

Profile drag.

Drag incurred from frictional or parasitic

resistance of the blades passing through the air. It does not
change significantly with the angle of attack of the airfoil
section, but it increases moderately as airspeed increases.

Resultant relative wind.

Airflow from rotation that is

modified by induced flow.

Retreating blade.

Any blade, located in a semicircular part

of the rotor disk, in which the blade direction is opposite to
the direction of flight.

G-5

Retreating blade stall.

A stall that begins at or near the tip

of a blade in a helicopter because of the high angles of attack
required to compensate for dissymmetry of lift.

Rigid rotor.

A rotor system permitting blades to feather,

but not flap or hunt.

Rotational velocity.

The component of relative wind

produced by the rotation of the rotor blades.

Rotor.

A complete system of rotating airfoils creating lift

for a helicopter.

Rotor brake.

A device used to stop the rotor blades during

shutdown.

Rotor disk area.

See disk area.

Rotor force.

The force produced by the rotor, comprised of

rotor lift and rotor drag.

Semirigid rotor.

A rotor system in which the blades are fixed

to the hub, but are free to flap and feather.

Shaft turbine.

A turbine engine used to drive an output shaft,

commonly used in helicopters.

Skid.

A flight condition in which the rate of turn is too great

for the angle of bank.

Skid shoes.

Plates attached to the bottom of skid landing

gear, protecting the skid.

Slip.

A flight condition in which the rate of turn is too slow

for the angle of bank.

Solidity ratio.

The ratio of the total rotor blade area to total

rotor disk area.

Span.

The dimension of a rotor blade or airfoil from root

to tip.

Split needles.

A term used to describe the position of the

two needles on the engine/rotor tachometer when the two
needles are not superimposed.

Standard atmosphere.

A hypothetical atmosphere based on

averages in which the surface temperature is 59 °F (15 °C),
the surface pressure is 29.92 "Hg (1013.2 Mb) at sea level,
and the temperature lapse rate is approximately 3.5 °F (2
°C) per 1,000 feet.

Static stop.

A device used to limit the blade flap, or rotor

flap, at low rpm or when the rotor is stopped.

Steady-state flight.

The type of flight experienced when a

helicopter is in straight-and-level, unaccelerated flight, and
all forces are in balance.

Symmetrical airfoil.

An airfoil having the same shape on

the top and bottom.

Tail rotor.

A rotor turning in a plane perpendicular to that

of the main rotor and parallel to the longitudinal axis of the
fuselage. It is used to control the torque of the main rotor and
to provide movement about the yaw axis of the helicopter.

Teetering hinge.

A hinge that permits the rotor blades of a

semirigid rotor system to flap as a unit.

Thrust.

The force developed by the rotor blades acting

parallel to the relative wind and opposing the forces of drag
and weight.

Tip-path plane.

The imaginary circular plane outlined by

the rotor blade tips as they make a cycle of rotation.

Torque.

In helicopters with a single, main rotor system, the

tendency of the helicopter to turn in the opposite direction
of the main rotor rotation.

Trailing edge.

The rearmost edge of an airfoil.

Translating tendency.

The tendency of the single-rotor

helicopter to move laterally during hovering flight. Also
called tail rotor drift.

Translational lift.

The additional lift obtained when entering

forward flight, due to the increased efficiency of the rotor
system.

Transverse-flow effect.

The condition of increased drag

and decreased lift in the aft portion of the rotor disk caused
by the air having a greater induced velocity and angle in the
aft portion of the disk.

True altitude.

The actual height of an object above mean

sea level.

Turboshaft engine.

A turbine engine transmitting power

through a shaft as would be found in a turbine helicopter.

Twist grip.

The power control on the end of the collective

control.

Underslung.

A rotor hub that rotates below the top of the

mast, as on semirigid rotor systems.

G-6

Unloaded rotor.

The state of a rotor when rotor force has

been removed, or when the rotor is operating under a low or
negative G condition.

Useful load.

The difference between the gross weight and

the basic empty weight. It includes the flight crew, usable
fuel, drainable oil, if applicable, and payload.

Variation.

The angular difference between true north and

magnetic north; indicated on charts by isogonic lines.

Vertical vibration.

A vibration in which the movement is

up and down, or vertical, as in an out-of-track condition.

Vortex ring state.

A transient condition of downward flight

(descending through air after just previously being accelerated
downward by the rotor) during which an appreciable portion
of the main rotor system is being forced to operate at angles
of attack above maximum. Blade stall starts near the hub and
progresses outward as the rate of descent increases.

Weight.

One of the four main forces acting on a helicopter.

Equivalent to the actual weight of the helicopter. It acts
downward toward the center of the earth.

Yaw.

The movement of a helicopter about its vertical axis.

Index

Abnormal Vibrations .................................................11-22
Accessory Gearbox ......................................................4-10
Advancing Blade ..........................................................2-19
After Landing and Securing ...........................................8-6
Aircraft Servicing ...........................................................8-3
Airflow

horizontal part.............................................................2-9
vertical part .................................................................2-9

Airflow in Forward Flight ............................................2-19
Airfoil .............................................................................2-7

nonsymmetrical airfoil (cambered) ............................2-8
symmetrical Airfoil ....................................................2-8

Airframe .........................................................................4-1
Angle of attack (AOA) .......................................... 2-8,2-13
Angle of incidence ................................................ 2-8,2-12
Anti-Icing Systems .......................................................4-19
Antitorque Drive Systems ..............................................4-8
Antitorque Pedals .................................................... 1-6,3-4
Antitorque System .........................................................4-7

Fenestron ....................................................................4-7
NOTAR® ...................................................................4-8

Antitorque System Failure .........................................11-16
Approach and Landing ...................................... 10-11,12-9
Approaches ..................................................................9-18
Astigmatism .................................................................12-2
Atmospheric Illusions ................................................12-10
Autopilot ......................................................................4-18
Autorotation ................................................ 2-25,2-26,11-2
Autorotational Performance ...........................................7-4
Autorotation With Turns ..............................................11-6

Bearingless Rotor System ..............................................4-4
Belt Drive Clutch .........................................................4-12
Bernoulli's Principle .......................................................2-3
Blade span ......................................................................2-7

Callouts ......................................................................13-18
Carburetor Ice ..............................................................4-14

Center of Gravity ...........................................................6-2
Center of pressure ..........................................................2-8
Centrifugal Clutch ........................................................4-12
CG Aft of Aft Limit .......................................................6-3
Chord..............................................................................2-8
Chord line .......................................................................2-8
Clutch ...........................................................................4-12
Coaxial rotors .......................................................... 1-4,4-6
Cockpit Lights ..............................................................12-8
Collective pitch control ........................................... 1-5,3-2
Collision Avoidance at Night .......................................12-9
Combustion Chamber ..................................................4-10
Compressor ....................................................................4-9
Coning ..........................................................................2-15
Control Inputs

cyclic ..........................................................................1-5

Coriolis Effect (Law of Conservation of Angular
Momentum) ..................................................................2-16
Critical Conditions .....................................................11-12
Crosswind Considerations During Takeoffs ................9-13

d’Amécourt, Gustave de Ponton ....................................1-1
Decision-Making Process ............................................13-4
Density Altitude .............................................................7-2
Determining Empty Weight ...........................................6-2
Dissymmetry of Lift .....................................................2-23
Downwash ....................................................................2-11
Drag ......................................................................... 2-3,2-6

induced drag ...............................................................2-7
parasite drag ...............................................................2-7
profile drag .................................................................2-6
total drag .....................................................................2-7

Dynamic Rollover ......................................................11-11

Effective Translational Lift (ETL) ...............................2-22
Effect of Weight Versus Density Altitude .....................7-3
elastomeric bearings .......................................................4-6
Electrical Systems ........................................................4-16
Emergency Equipment and Survival Gear .................11-27
Engine Fuel Control System ........................................4-14

I-2

Engines ...........................................................................4-8

reciprocating engine ...................................................4-8
turbine engine .............................................................4-8

Engine Starting and Rotor Engagement ................ 8-3,12-8
En Route Procedures ....................................................12-9
Environmental Systems ...............................................4-18

Fenestron ........................................................................1-3
Flicker Vertigo .............................................................12-7
Flight Mode Annunciator (FMA) ..............................13-18
Flightpath velocity .........................................................2-8
Four Fundamentals .........................................................9-2
Freewheeling Unit ..........................................................4-7
Fuel Supply System .....................................................4-13
Fuselage .........................................................................4-2

General Aviation Manufacturers Association (GAMA) 5-1
Go-Around ...................................................................9-20
Governor/Correlator .......................................................3-2
Ground Lighting Illusions ..........................................12-10
Ground Reference Maneuvers .....................................9-13

rectangular course.....................................................9-14
S-turns ......................................................................9-15
turns around a point ..................................................9-16

Ground Resonance .....................................................11-11
Gyroscopic Precession .................................................2-17

Heading Control .............................................................3-4
Height/Velocity Diagram ...............................................7-2
helicopter ........................................................................1-1
Helicopter Night VFR Operations .............................12-10
High and Low Density Altitude Conditions ..................7-2
Hovering

flight .........................................................................2-14
forward flight ..............................................................9-9
performance ................................................................7-4
sideward flight ............................................................9-9
taxi ............................................................................9-10
turn .............................................................................9-7

Hub .................................................................................2-9
Humidity ........................................................................7-2
Hydraulics ....................................................................4-16

Illusions Leading to Landing Errors ............................12-9

Induced flow ......................................................... 2-8,2-22

downwash .................................................................2-11

In-Ground Effect ..........................................................2-12
Intermeshing rotors ................................................. 1-4,4-6

Kaman, Charles H. .........................................................1-2

Landing

stuck left pedal........................................................11-17
stuck neutral or right pedal .....................................11-17

Leading edge ..................................................................2-8
Lift ..................................................................................2-3
Loading Chart Method ...................................................6-4
Low-G Conditions and Mast Bumping ......................11-14
Low Reconnaissance ....................................................10-2
Low Rotor RPM and Rotor Stall ...............................11-15
LTE at Altitude ..........................................................11-21

Main Rotor

disk interference (285–315°) ..................................11-20
system .........................................................................4-2
transmission ..............................................................4-11

Maximum Performance Takeoff ..................................10-2
Medium and High Frequency Vibrations ..................11-23
Minimum Equipment Lists (MELs) and Operations with
Inoperative Equipment ...................................................8-2
Moisture .........................................................................7-2
Multi-Engine Emergency Operations ........................11-23
Myopia .........................................................................12-2

Newton’s Third Law of Motion .....................................2-5
Night Flight ..................................................................12-7
Night Myopia ...............................................................12-2
Night Traffic Patterns ..................................................12-8
Night Vision .................................................................12-4
Normal Approach to a Hover .......................................9-19
Normal Approach to the Surface .................................9-20
Normal Descent .............................................................9-5
Normal Takeoff From a Hover ....................................9-12
Normal Takeoff From the Surface ...............................9-12
Normal Takeoffs and Landings .................................11-13
NOTAR® .......................................................................1-3

I-3

Obstruction Detection ..................................................12-5
Oculogravic illusion ...................................................13-13
Out of Ground Effect ...................................................2-12

Passengers ......................................................................8-4
PAVE Checklist ...........................................................13-6
Pendular Action ...........................................................2-15
Performance Charts ........................................................7-2

climb performance ......................................................7-6

Pilot at the Flight Controls .............................................8-6
Pinnacle and Ridgeline Operations ............................10-11
Pitch Control ................................................................2-17
Powered Flight .............................................................2-14
Power Failure in a Hover .............................................11-8
Practice Autorotation With A Power Recovery ...........11-7
Preflight ................................................................. 8-2,12-7
Presbyopia ....................................................................12-2

Ramp Attendants and Aircraft Servicing Personnel ......8-4
Rapid Deceleration or Quick Stop ...............................10-4
Rearward Flight ...........................................................2-24
Reciprocating Engines .................................................4-14
Reconnaissance Procedures .........................................10-2
Recovery From Low Rotor RPM ...............................11-16
Recovery Technique ..................................................11-21
Relative-Motion Illusion ..............................................12-6
Relative wind .......................................................... 2-8,2-9
Resultant relative wind ........................................... 2-8,2-9
Retreating Blade ...........................................................2-20
Retreating Blade Stall ................................................11-10
Reversible Perspective Illusion ....................................12-6
Rigid Rotor System ........................................................4-3
Rods .............................................................................12-4
Root ................................................................................2-9
Rotational Relative Wind (Tip Path Plane) ...................2-9
Rotorcraft .......................................................................1-1
Rotorcraft Flight Manual (RFM) ...................................5-1

aircraft and systems description .................................5-5
emergency procedures ................................................5-4
general information ....................................................5-2
handling, servicing, and maintenance ........................5-5
normal procedures ......................................................5-5
operating limitations ...................................................5-2

airspeed ...................................................................5-2
altitude ....................................................................5-3
flight ........................................................................5-4

placards ...................................................................5-4
powerplant ..............................................................5-3
rotor .........................................................................5-3
weight and loading distribution ..............................5-4

performance ................................................................5-5
preliminary pages .......................................................5-2
safety and operational tips ..........................................5-6
supplements ................................................................5-6
weight and balance .....................................................5-5

Rotor Safety Considerations ..........................................8-3
Rotor System ..................................................................1-3
Running/Rolling Takeoff .............................................10-3

Shallow Approach and Running/Roll-On Landing ......10-6
Sideward Flight ............................................................2-23
Sikorsky, Igor .................................................................1-2
Single-Engine Failure ................................................11-23
Slips................................................................................9-4
Slope Takeoff ...............................................................10-8
Slope Takeoffs and Landings .....................................11-13
Stability Augmentations Systems ................................4-17
Structural Design .........................................................4-12
Swash Plate Assembly ...................................................4-6
synchropter .....................................................................1-4
System Malfunctions .................................................11-16

Takeoff .......................................................................10-10
Tandem rotor ........................................................... 1-3,4-6
Taxiing .........................................................................9-10
Taxi Technique ............................................................12-8
The Effect of Weight Versus Density Altitude ..............7-3
The Four Fundamentals .................................................9-2
Throttle ...........................................................................1-6
Throttle Control .............................................................3-2
Thrust ...................................................................... 2-3,2-6
Tip ..................................................................................2-9
Traffic Patterns .............................................................9-17
Trailing edge ..................................................................2-8
Translating Tendency or Drift .....................................2-15
Translational Lift .........................................................2-21
Transmission System ...................................................4-10
Transverse Flow Effect ................................................2-23
Turbine .........................................................................4-10
Turbine Age ...................................................................1-2
Turbine Engines ...........................................................4-16
Turning Flight ..............................................................2-24
Turns ..............................................................................9-3
Twist ..............................................................................2-9

Helicopter Flying Handbook (2019) - page 6