Pilot's Handbook of Aeronautical Knowledge
Preface
Acknowledgements
Table of Contents
Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5,
Flight Controls
Chapter 6,
Aircraft Systems
Chapter 7,
Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9,
Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12,
Aviation Weather Services
Chapter 13,
Airport Operation
Chapter 14,
Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making
Appendix
Glossary
Index |
Management of Weight and Balance Control
Title 14 of the Code of Federal Regulations (14 CFR) section
23.23 requires establishment of the ranges of weights and
CGs within which an aircraft may be operated safely. The
manufacturer provides this information, which is included in
the approved AFM, TCDS, or aircraft specifications.
While there are no specified requirements for a pilot operating
under 14 CFR part 91 to conduct weight and balance
calculations prior to each flight, 14 CFR section 91.9 requires
the pilot in command (PIC) to comply with the operating
limits in the approved AFM. These limits include the weight
and balance of the aircraft. To enable pilots to make weight
and balance computations, charts and graphs are provided
in the approved AFM.
Weight and balance control should be a matter of concern to
all pilots. The pilot controls loading and fuel management
(the two variable factors that can change both total weight
and CG location) of a particular aircraft. The aircraft owner
or operator should make certain that up-to-date information
is available for pilot use, and should ensure that appropriate
entries are made in the records when repairs or modifications
have been accomplished. The removal or addition of
equipment results in changes to the CG.
Weight changes must be accounted for and the proper
notations made in weight and balance records. The equipment
list must be updated, if appropriate. Without such information,
the pilot has no foundation upon which to base the necessary
calculations and decisions.
Standard parts with negligible weight or the addition of
minor items of equipment such as nuts, bolts, washers,
rivets, and similar standard parts of negligible weight on
fixed-wing aircraft do not require a weight and balance
check. Rotorcraft are, in general, more critical with respect
to control with changes in the CG position. The following
criteria for negligible weight change is outlined in Advisory
Circular (AC) 43.13-1 (as revised), Methods Techniques and
Practices—Aircraft Inspection and Repair:
• One pound or less for an aircraft whose weight empty
is less than 5,000 pounds;
• Two pounds or less for aircraft with an empty weight
of more than 5,000 pounds to 50,000 pounds;
• Five pounds or less for aircraft with an empty weight
of more than 50,000 pounds. |
Negligible CG change is any change of less than 0.05 percent
Mean Aerodynamic Chord (MAC) for fixed-wing aircraft, 0.2
percent of the maximum allowable CG range for rotorcraft.
Exceeding these limits would require a weight and balance
check.
Before any flight, the pilot should determine the weight
and balance condition of the aircraft. Simple and orderly
procedures based on sound principles have been devised
by the manufacturer for the determination of loading
conditions. The pilot uses these procedures and exercises
good judgment when determining weight and balance. In
many modern aircraft, it is not possible to fill all seats,
baggage compartments, and fuel tanks, and still remain within
the approved weight and balance limits. If the maximum
passenger load is carried, the pilot must often reduce the fuel
load or reduce the amount of baggage.
14 CFR part 125 requires aircraft with 20 or more seats or
weighing 6,000 pounds or more to be weighed every 36
calendar months. Multi-engine aircraft operated under a
14 CFR part 135 are also required to be weighed every 36
months. Aircraft operated under 14 CFR part 135 are exempt
from the 36 month requirement if operated under a weight
and balance system approved in the operations specifications
of the certificate holder. AC 43.13-1, Acceptable Methods,
Techniques and Practices—Aircraft Inspection and Repair
also requires that the aircraft mechanic must ensure the
weight and balance data in the aircraft records is current and
accurate after a 100-hour or annual inspection. |
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