Title 14 of the Code of Federal Regulations (14 CFR)
part 91 requires that pilots comply with the operating
limitations specified in approved rotorcraft flight man-
uals, markings, and placards. Originally, flight manuals
were often characterized by a lack of essential infor-
mation and followed whatever format and content the
manufacturer felt was appropriate. This changed with
the acceptance of the General Aviation Manufacturers
Association’s (GAMA) Specification for Pilot’ s
Operating Handbook, which established a standardized
format for all general aviation airplane and rotorcraft
flight manuals. The term “Pilot’s Operating Handbook
(POH)” is often used in place of “Rotorcraft Flight
Manual (RFM).” However, if “Pilot’s Operating
Handbook” is used as the main title instead of “Rotorcraft
Flight Manual,” a statement must be included on the title
page indicating that the document is the FAA-Approved
Rotorcraft Flight Manual. [Figure 6-1]
Besides the preliminary pages, an FAA-Approved
Rotorcraft Flight Manual may contain as many as ten sec-
tions. These sections are: General Information; Operating
Limitations; Emergency Procedures; Normal Procedures;
Performance; Weight and Balance; Aircraft and Systems
Description; Handling, Servicing, and Maintenance; and
Supplements. Manufacturers have the option of including
a tenth section on Safety and Operational Tips and an
alphabetical index at the end of the handbook.
PRELIMINARY PAGES
While rotorcraft flight manuals may appear similar for
the same make and model of aircraft, each flight man-
ual is unique since it contains specific information
about a particular aircraft, such as the equipment
installed, and weight and balance information.
Therefore, manufacturers are required to include the
serial number and registration on the title page to iden-
tify the aircraft to which the flight manual belongs. If a
flight manual does not indicate a specific aircraft regis-
tration and serial number, it is limited to general study
purposes only.
Most manufacturers include a table of contents, which
identifies the order of the entire manual by section num-
ber and title. Usually, each section also contains its own
table of contents. Page numbers reflect the section you
are reading, 1-1, 2-1, 3-1, and so on. If the flight manual
is published in looseleaf form, each section is usually
marked with a divider tab indicating the section number
or title, or both. The Emergency Procedures section may
have a red tab for quick identification and reference.
GENERAL INFORMATION
The General Information section provides the basic
descriptive information on the rotorcraft and the power-
plant. In some manuals there is a three-view drawing of
the rotorcraft that provides the dimensions of various
components, including the overall length and width, and
the diameter of the rotor systems. This is a good place to
quickly familiarize yourself with the aircraft.
You can find definitions, abbreviations, explanations of
symbology, and some of the terminology used in the
manual at the end of this section. At the option of the
manufacturer, metric and other conversion tables may
also be included.
OPERATING LIMITATIONS
The Operating Limitations section contains only those
limitations required by regulation or that are necessary
for the safe operation of the rotorcraft, powerplant, sys-
tems, and equipment. It includes operating limitations,
instrument markings, color coding, and basic placards.
Some of the areas included are: airspeed, altitude, rotor,
and powerplant limitations, including fuel and oil
requirements; weight and loading distribution; and
flight limitations.
AIRSPEED LIMITATIONS
Airspeed limitations are shown on the airspeed indica-
tor by color coding and on placards or graphs in the
Figure 6-1. The Rotorcraft Flight Manual is a regulatory docu-
ment in terms of the maneuvers, procedures, and operating
limitations described therein.
aircraft. A red line on the airspeed indicator shows the
airspeed limit beyond which structural damage could
occur. This is called the never exceed speed, or V NE.
The normal operating speed range is depicted by a green
arc. A blue line is sometimes added to show the maxi-
mum safe autorotation speed. [Figure 6-2]
ALTITUDE LIMITATIONS
If the rotorcraft has a maximum operating density alti-
tude, it is indicated in this section of the flight manual.
Sometimes the maximum altitude varies based on differ-
ent gross weights.
ROTOR LIMITATIONS
Low rotor r.p.m. does not produce sufficient lift, and
high r.p.m. may cause structural damage, therefore
rotor r.p.m. limitations have minimum and maximum
values. A green arc depicts the normal operating range
with red lines showing the minimum and maximum
limits. [Figure 6-3]
There are two different rotor r.p.m. limitations: power-on
and power-off. Power-on limitations apply anytime the
engine is turning the rotor and is depicted by a fairly nar-
row green band. A yellow arc may be included to show a
transition range, which means that operation within this
range is limited. Power-off limitations apply anytime the
engine is not turning the rotor, such as when in an autoro-
tation. In this case, the green arc is wider than the power-
on arc, indicating a larger operating range.
POWERPLANT LIMITATIONS
The Powerplant Limitations area describes operating
limitations on the rotorcraft’s engine including such
items as r.p.m. range, power limitations, operating tem-
peratures, and fuel and oil requirements. Most turbine
engines and some reciprocating engines have a maxi-
mum power and a maximum continuous power rating.
The “maximum power” rating is the maximum power
the engine can generate and is usually limited by time.
The maximum power range is depicted by a yellow arc
on the engine power instruments, with a red line indi-
cating the maximum power that must not be exceeded.
“Maximum continuous power” is the maximum power
the engine can generate continually, and is depicted by
a green arc. [Figure 6-4]
Like on a torque and turbine outlet temperature gauge,
the red line on a manifold pressure gauge indicates the
maximum amount of power. A yellow arc on the gauge
warns of pressures approaching the limit of rated
power. A placard near the gauge lists the maximum
readings for specific conditions. [Figure 6-5]
WEIGHT AND LOADING DISTRIBUTION
The Weight and Loading Distribution area contains the
maximum certificated weights, as well as the center of
gravity (CG) range. The location of the reference datum
used in balance computations should also be included in
this section. Weight and balance computations are not
provided here, but rather in the Weight and Balance
Section of the FAA-Approved Rotocraft Flight Manual.
150 20
AIRSPEED
KNOTS
MPH
X 10
Figure 6-2. Typical airspeed indicator limitations and mark-
ings.
ROTOR
ENGINE
RPM
Figure 6-3. Markings on a typical dual-needle tachometer in a
reciprocating-engine helicopter. The outer band shows the
limits of the superimposed needles when the engine is turn-
ing the rotor. The inner band indicates the power-off limits.
50 60 70
TORQUE
PERCENT
4 5
TURB
OUT
TEMP
ϒC X 100
Figure 6-4. Torque and turbine outlet temperature (TOT)
gauges are commonly used with turbine-powered aircraft.
FLIGHT LIMITATIONS
This area lists any maneuvers which are prohibited,
such as acrobatic flight or flight into known icing con-
ditions. If the rotorcraft can only be flown in VFR
conditions, it will be noted in this area. Also included
are the minimum crew requirements, and the pilot seat
location, if applicable, where solo flights must be con-
ducted.
PLACARDS
All rotorcraft generally have one or more placards dis-
played that have a direct and important bearing on the
safe operation of the rotorcraft. These placards are
located in a conspicuous place within the cabin and
normally appear in the Limitations Section. Since V NE
changes with altitude, this placard can be found in all
helicopters. [Figure 6-6]
EMERGENCY PROCEDURES
Concise checklists describing the recommended proce-
dures and airspeeds for coping with various types of
emergencies or critical situations can be found in this
section. Some of the emergencies covered include:
engine failure in a hover and at altitude, tail rotor fail-
ures, fires, and systems failures. The procedures for
restarting an engine and for ditching in the water might
also be included.
Manufacturers may first show the emergencies check-
lists in an abbreviated form with the order of items
reflecting the sequence of action. This is followed by
amplified checklists providing additional information
to help you understand the procedure. To be prepared
for an abnormal or emergency situation, memorize the
first steps of each checklist, if not all the steps. If time
permits, you can then refer to the checklist to make sure
all items have been covered. (For more information on
emergencies, refer to Chapter 11—Helicopter Emergencies
and Chapter 21—Gyroplane Emergencies.)
Manufacturers also are encouraged to include an optional
area titled “Abnormal Procedures,” which describes rec-
ommended procedures for handling malfunctions that are
not considered to be emergencies. This information
would most likely be found in larger helicopters.
NORMAL PROCEDURES
The Normal Procedures is the section you will proba-
bly use the most. It usually begins with a listing of the
airspeeds, which may enhance the safety of normal
operations. It is a good idea to memorize the airspeeds
that are used for normal flight operations. The next part
of the section includes several checklists, which take
you through the preflight inspection, before starting
procedure, how to start the engine, rotor engagement,
ground checks, takeoff, approach, landing, and shut-
down. Some manufacturers also include the procedures
for practice autorotations. To avoid skipping an impor-
tant step, you should always use a checklist when one is
available. (More information on maneuvers can be
found in Chapter 9—Basic Maneuvers, Chapter 10—
Advanced Maneuvers, and Chapter 20—Gyroplane
Flight Operations.)
PERFORMANCE
The Performance Section contains all the information
required by the regulations, and any additional per-
formance information the manufacturer feels may
enhance your ability to safely operate the rotorcraft.
MANIFOLD
PRESSURE
INCHES
OF MERCURY
Figure 6-5. A manifold pressure gauge is commonly used
with piston-powered aircraft.
Press Alt.
1,000 FT
F OAT 8 4 6 8 10 12 14
0 109 109 105 84 61 -- --
109 109 109 109 98 77 58
109 109 109 109 85 67 48
109 109 109 96 75 57 --
109 109 108 84 66 48 --
109 109 95 74 57 -- --
109 108 84 66 48 -- --
109 109 94 72 49 -- --
09 103 81 59 -- -- --
109 91 70 48 -- -- --
109 80 59 -- -- -- --
109 70 48 -- -- -- --
MAXIMUM VNE DOORS OFF - 102 MPH IAS
VNE - MPH IAS
GROSS□
WEIGHT
MORE□
THAN□
1,700□
LBS
1,700□
LBS□
OR□
LESS
NEVER EXCEED SPEED
Pressure Alt. 1,000 Feet
0 2 4 6 8 10 12 14
KIAS
VNE -20ϒ C
0ϒ C+20ϒ C+40ϒ C
MAX ALT.
Figure 6-6. Various VNE placards.
ers should describe the systems in a manner that is
understandable to most pilots. For larger, more com-
plex rotorcraft, the manufacturer may assume a higher
degree of knowledge. (For more information on rotor-
craft systems, refer to Chapter 5—Helicopter Systems
and Chapter 18—Gyroplane Systems.)
HANDLING, SERVICING, AND
MAINTENANCE
The Handling, Servicing, and Maintenance section
describes the maintenance and inspections recom-
mended by the manufacturer, as well as those required
by the regulations, and Airworthiness Directive (AD)
compliance procedures. There are also suggestions on
how the pilot/operator can ensure that the work is done
properly.
This section also describes preventative maintenance
that may be accomplished by certificated pilots, as
well as the manufacturer’s recommended ground han-
dling procedures, including considerations for
hangaring, tie down, and general storage procedures
for the rotorcraft.
SUPPLEMENTS
The Supplements Section describes pertinent informa-
tion necessary to operate optional equipment installed on
the rotorcraft that would not be installed on a standard
aircraft. Some of this information may be supplied by the
aircraft manufacturer, or by the maker of the optional
equipment. The information is then inserted into the
flight manual at the time the equipment is installed.
SAFETY AND OPERATIONAL TIPS
The Safety and Operational Tips is an optional section
that contains a review of information that could
enhance the safety of the operation. Some examples of
the information that might be covered include: physio-
logical factors, general weather information, fuel con-
servation procedures, external load warnings, low rotor
r.p.m. considerations, and recommendations that if not
adhered to could lead to an emergency.
Airworthiness Directive (AD)—A
regulatory notice that is sent out
by the FAA to the registered own-
ers of aircraft informing them of
the discovery of a condition that
keeps their aircraft from continu-
ing to meet its conditions for air-
worthiness. Airworthiness
Directives must be complied with
within the required time limit, and
the fact of compliance, the date of
compliance, and the method of
compliance must be recorded in
the aircraft maintenance records.
These charts, graphs, and tables vary in style but all
contain the same basic information. Some examples
of the performance information that can be found in
most flight manuals include a calibrated versus indi-
cated airspeed conversion graph, hovering ceiling
versus gross weight charts, and a height-velocity dia-
gram. [Figure 6-7] For information on how to use the
charts, graphs, and tables, refer to Chapter 8—
Performance.
WEIGHT AND BALANCE
The Weight and Balance section should contain all the
information required by the FAA that is necessary to
calculate weight and balance. To help you correctly
compute the proper data, most manufacturers include
sample problems. (Weight and balance is further dis-
cussed in Chapter 7—Weight and Balance.)
AIRCRAFT AND SYSTEMS
DESCRIPTION
The Aircraft and Systems Description section is an
excellent place to study and familiarize yourself with
all the systems found on your aircraft. The manufactur-
1,5001,400
2,000
4,000
6,000
8,000
10,000
12,000
1,600 1,700 1,800
PRESSURE ALTITUDE ~ FEET
GROSS WEIGHT ~ LBS
8,000 FT.□
DENSITY ALTITUDE
MIXTURE□
FULL RICH
OAT 120ϒF
OAT 100ϒF
OAT 80ϒF
OAT 60ϒF
OAT 40ϒF
OAT 20ϒF
OAT 0ϒF
Figure 6-7. One of the performance charts in the Performance
Section is the “In Ground Effect Hover Ceiling versus Gross
Weight” chart. This chart allows you to determine how much
weight you can carry and still operate at a specific pressure
altitude, or if you are carrying a specific weight, what is your
altitude limitation.
It is vital to comply with weight and balance limits
established for helicopters. Operating above the maxi-
mum weight limitation compromises the structural
integrity of the helicopter and adversely affects per-
formance. Balance is also critical because on some
fully loaded helicopters, center of gravity deviations as
small as three inches can dramatically change a heli-
copter’s handling characteristics. Taking off in a heli-
copter that is not within the weight and balance
limitations is unsafe.
WEIGHT
When determining if your helicopter is within the
weight limits, you must consider the weight of the basic
helicopter, crew, passengers, cargo, and fuel. Although
the effective weight (load factor) varies during maneu-
vering flight, this chapter primarily considers the
weight of the loaded helicopter while at rest.
The following terms are used when computing a heli-
copter’s weight.
BASIC EMPTY WEIGHT— The starting point for
weight computations is the basic empty weight, which
is the weight of the standard helicopter, optional
equipment, unusable fuel, and full operating fluids
including full engine oil. Some helicopters might use
the term “licensed empty weight,” which is nearly the
same as basic empty weight, except that it does not
include full engine oil, just undrainable oil. If you fly a
helicopter that lists a licensed empty weight, be sure to
add the weight of the oil to your computations.
USEFUL LOAD —The difference between the gross
weight and the basic empty weight is referred to as
useful load. It includes the flight crew, usable fuel,
drainable oil, if applicable, and payload.
PAYLOAD—The weight of the passengers, cargo, and
baggage.
GROSS WEIGHT—The sum of the basic empty weight
and useful load.
MAXIMUM GROSS WEIGHT — The maximum
weight of the helicopter. Most helicopters have an inter-
nal maximum gross weight, which refers to the weight
within the helicopter structure and an external maximum
gross weight, which refers to the weight of the helicopter
with an external load.
WEIGHT LIMITATIONS
Weight limitations are necessary to guarantee the struc-
tural integrity of the helicopter, as well as enabling you
to predict helicopter performance accurately. Although
aircraft manufacturers build in safety factors, you
should never intentionally exceed the load limits for
which a helicopter is certificated. Operating above a
maximum weight could result in structural deformation
or failure during flight if you encounter excessive load
factors, strong wind gusts, or turbulence. Operating
below a minimum weight could adversely affect the
handling characteristics of the helicopter. During sin-
gle-pilot operations in some helicopters, you may have
to use a large amount of forward cyclic in order to
maintain a hover. By adding ballast to the helicopter,
the cyclic will be closer to the center, which gives you
a greater range of control motion in every direction.
Additional weight also improves autorotational charac-
teristics since the autorotational descent can be estab-
lished sooner. In addition, operating below minimum
weight could prevent you from achieving the desirable
rotor r.p.m. during autorotations.
Although a helicopter is certificated for a specified
maximum gross weight, it is not safe to take off with
this load under all conditions. Anything that adversely
affects takeoff, climb, hovering, and landing perform-
ance may require off-loading of fuel, passengers, or
baggage to some weight less than the published maxi-
mum. Factors which can affect performance include
high altitude, high temperature, and high humidity con-
ditions, which result in a high density altitude.
DETERMINING EMPTY WEIGHT
A helicopter’s weight and balance records contain
essential data, including a complete list of all installed
optional equipment. Use these records to determine the
weight and balance condition of the empty helicopter.
When a helicopter is delivered from the factory, the basic
empty weight, empty weight center of gravity (CG), and
useful load are recorded on a weight and balance data
sheet included in the FAA-Approved Rotocraft Flight
Manual. The basic empty weight can vary even in the
same model of helicopter because of differences in
installed equipment. If the owner or operator of a heli-
copter has equipment removed, replaced, or additional
equipment installed, these changes must be reflected in
the weight and balance records. In addition, major
repairs or alterations must be recorded by a certified
mechanic. When the revised weight and moment are
recorded on a new form, the old record is marked with
the word “superseded” and dated with the effective
date of the new record. This makes it easy to determine
which weight and balance form is the latest version.
You must use the latest weight and balance data for
computing all loading problems.
BALANCE
Helicopter performance is not only affected by gross
weight, but also by the position of that weight. It is
essential to load the aircraft within the allowable center-
of-gravity range specified in the rotorcraft flight man-
ual’s weight and balance limitations.
CENTER OF GRAVITY (CG)
The center of gravity is defined as the theoretical point
where all of the aircraft’s weight is considered to be
concentrated. If a helicopter was suspended by a cable
attached to the center-of-gravity point, it would balance
like a teeter-totter. For helicopters with a single main
rotor, the CG is usually close to the main rotor mast.
Improper balance of a helicopter’s load can result in
serious control problems. The allowable range in which
the CG may fall is called the “CG range.” The exact
CG location and range are specified in the rotorcraft
flight manual for each helicopter. In addition to making
a helicopter difficult to control, an out-of-balance load-
ing condition also decreases maneuverability since
cyclic control is less effective in the direction opposite
to the CG location.
Ideally, you should try to perfectly balance a helicopter
so that the fuselage remains horizontal in hovering
flight, with no cyclic pitch control needed except for
wind correction. Since the fuselage acts as a pendulum
suspended from the rotor, changing the center of grav-
ity changes the angle at which the aircraft hangs from
the rotor. When the center of gravity is directly under
the rotor mast, the helicopter hangs horizontal; if the
CG is too far forward of the mast, the helicopter hangs
with its nose tilted down; if the CG is too far aft of the
mast, the nose tilts up. [Figure 7-1]
CG FORWARD OF FORWARD LIMIT
A forward CG may occur when a heavy pilot and pas-
senger take off without baggage or proper ballast
located aft of the rotor mast. This situation becomes
worse if the fuel tanks are located aft of the rotor mast
because as fuel burns the weight located aft of the rotor
mast becomes less.
You can recognize this condition when coming to a
hover following a vertical takeoff. The helicopter will
have a nose-low attitude, and you will need excessive
rearward displacement of the cyclic control to maintain
a hover in a no-wind condition. You should not continue
flight in this condition, since you could rapidly run out
of rearward cyclic control as you consume fuel. You also
may find it impossible to decelerate sufficiently to bring
the helicopter to a stop. In the event of engine failure and
the resulting autorotation, you may not have enough
cyclic control to flare properly for the landing.
A forward CG will not be as obvious when hovering into
a strong wind, since less rearward cyclic displacement is
required than when hovering with no wind. When deter-
mining whether a critical balance condition exists, it is
essential to consider the wind velocity and its relation to
the rearward displacement of the cyclic control.
CG AFT OF AFT LIMIT
Without proper ballast in the cockpit, exceeding the aft
CG may occur when:
• A lightweight pilot takes off solo with a full load
of fuel located aft of the rotor mast.
• A lightweight pilot takes off with maximum bag-
gage allowed in a baggage compartment located
aft of the rotor mast.
• A lightweight pilot takes off with a combination
of baggage and substantial fuel where both are aft
of the rotor mast.
You can recognize the aft CG condition when coming
to a hover following a vertical takeoff. The helicopter
will have a tail-low attitude, and you will need exces-
Forward CG□
□
CG Directly Under The Rotor Mast□
□
Aft CG□
Figure 7-1. The location of the center of gravity strongly influences how the helicopter handles.