Introduction
The largest weight changes that occur during the lifetime of
an aircraft are those caused by alterations and repairs. It is the
responsibility of the FAA-certificated mechanic or repairman
doing the work to accurately document the weight change
and record it in both the maintenance records and the Pilot’s
Operating Handbook/Aircraft Flight Manual (POH/AFM).
Center of Gravity Change After
a Repair or Alteration
Chapter 7
Figure 7-1. A typical 14 CFR part 23 weight and balance record.
Weight and Balance Record
(Continuous history of changes in structure or equipment affecting weight and balance)
Airplane Model Serial Number Page Number
Date
Item No.
In Out
Description
of Article or
Modification
Weight Change Running
Basic Empty
WeightAdded (+) Removed (−)
Wt.
(lb)
Wt.
(lb)
Arm
(in)
Moment/
1,000
Wt.
(lb)
Arm
(in)
Moment/
1,000
Moment/
1,000
As delivered 1,876 67.8
8-7-09 Alteration per FAA Form 337
Dated 8-7-09 7.38 .346 1,883.4 68.1
34-XX Turn coordinator –2.5 15.0 –.037 1,880.9 68.1
34-XX Directional gyro –3.12 13.5 –.042 1,877.8 68.1
22-XX Autopilot system 13.0 32.7 .425 1,890.8 68.5
Cessna 182L 118259080
Equipment List
The Federal Aviation Administration (FAA) considers
the addition or removal of equipment included in the
Comprehensive Equipment List to be a minor alteration.
The weights and arms are included with the items in the
equipment list, and these minor alterations can be done and the
aircraft approved for return to service by an FAA-certificate
mechanic or repairman. The only documentation required is an
entry in the aircraft maintenance records and the appropriate
change to the weight and balance record in the POH/AFM.
[Figure 7-1]
Figure 7-2 is a comprehensive list of all Cessna equipment
that is available for the Model 182S airplane. It should
not be confused with the airplane-specific equipment list.
An airplane-s pecific list is provided with each individual
airplane at delivery and is typically found at the end of the
Pilot’s Operating Handbook. The following comprehensive
equipment list and the airplane-specific list have a similar
order of listing.
The comprehensive equipment list provides the following
information in column form:
In the Item No column, each item is assigned a coded number.
The first two digits of the code represent the assignment
of an equipment item within the ATA Specification 100
breakdown (Chapter 11 for Placards, Chapter 21 for Air
Conditioning, Chapter 77 for Engine Indicating, etc.). These
assignments also correspond to the Maintenance Manual
chapter breakdown for the airplane. Items receive a unique
sequence number (01, 02, 03, etc.). After the sequence
number (and hyphen), a suffix letter is assigned to identify
an equipment item as required, standard, or optional. Suffix
letters are as follows:
–R = required item or equipment for FAA certificatio
–S = standard equipment item
–O = optional equipment item replacing required or
standard item(s)
–A = optional equipment item that is in addition to
required or standard items
In the Equipment List Description column, each item is
assigned a descriptive name to help identify its function.
In the Ref Drawing column, a drawing number is provided
that corresponds to the item.
Note: Additional equipment must be installed in accordance
with the reference drawing, service bulletin, or a separate
FAA approval.
In the Wt and Arm columns, you find the weight in pounds
and arm in inches of the equipment item.
Notes: Unless otherwise indicated, true values (not net
change values) for the weight and arm are shown. Positive
arms are distances aft of the airplane datum; negative
arms are distances forward of the datum. Asterisks (*) in
the weight and arm column indicate complete assembly
installations. Some major components of the assembly are
listed on the lines immediately following. The sum of these
major components does not necessarily equal the complete
assembly installation.
Figure 7-2. Typical comprehensive equipment list.
* Indicates total weight/arm for all subcomponents
Major Alteration and Repair
Within the following text, information concerning major
repairs or major alterations does not apply to any aircraft
within the light-sport category. This category of aircraft is
not eligible for major repairs or alterations.
Any major alteration or repair requires the work to be done
by an FAA-certificated mechanic or repairman or facility.
The work must be checked for conformity to FAA-approved
data and signed off by an aircraft mechanic holding an
Inspection Authorization (IA) or by an authorized agent of
an appropriately rated FAA-approved repair station. A Repair
Station record and/or FAA form 337, Major Repair and
Alteration, must be completed describing the work. (Reference
Title 14 of the Code of Federal Regulations (14 CFR) part 43,
appendix B, for the recording of major repair and alterations
requirements.) A dated and signed revision to the weight and
balance record is made and kept with the maintenance records,
and the airplane’s new empty weight and empty weight arm
or moment index are entered in the POH/AFM.
Weight and Balance Revision Record
Aircraft manufacturers use different formats for their weight
and balance data, but Figure 7-3 is typical of a weight and
balance revision record. All weight and balance records
should be kept with the other aircraft records. Each revision
record should be identified by the date, the aircraft make,
model, and serial number. The pages should be signed by
the person making the revision and his or her certificate type
and number must be included.
The computations for a weight and balance revision
are included on a weight and balance revision form.
Appropriate fore-and-aft extreme loading conditions should
be investigated and the computations shown. The date those
computations were made is shown in the upper right corner
of Figure 7-3. When this work is superseded, a notation
must be made on the new weight and balance revision form,
including a statement that the new computations supersede
the computations dated “MM/DD/YY.”
Figure 7-3. A typical airplane weight and balance revision record.
Weight & Balance
Cessna 182L
N42565
S/N 18259080
Removed the following equipment:
1. Turn coordinator P/N C661003-0201
2. Directional gyro P/N 0706000
Installed the following equipment:
1. S-TEC System 40 autopilot, includes
turn coordinator and directional gyro
*REVISED LICENSED EMPTY WEIGHT
NEW USEFUL LOAD 1,216.62
Forward check (Limit +33.0)
Wt. × Arm = Moment
A/C empty
Fwd. seats
Aft seats
Fuel (min.)
Baggage A
Baggage B
Jeseph P. Kline
A&P 123456789
Supersedes computations of FAA Form
337 dated 10/02/07.
Weight x Arm = Moment
2.50 lb 15.0 37.50
+3.12 lb 13.5 +42.12
5.62 79.62
1,876.00 36.14 67,798.64
−5.62 −79.62
1,870.38 36.20 67,719.02
Weight x Arm = Moment
13 lb 32.70 425.13
1,870.38 36.20 67,719.02
+13.00 +425.13
1,883.38 36.18 68,144.15
Rearward check (Limit +46.0)
A/C empty
Fwd. seats
Aft seats
Fuel (min.)
Baggage A
Baggage B
1,883.38 36.18 68,144.15
170.00 37.00 6,290.00
115.00 48.00 5,520.00
2,168.38 +36.87 79,954.15
Total
Aircraft after removal:
Wt. × Arm = Moment
1,883.38 36.18 68,144.15
170.00 37.00 6,290.00
340.00 74.00 25,160.00
528.00 48.20 25,449.60
100.00 97.00 9,700.00
60.00 116.00 6,960.00
3,081.38 45.98 141,703.75
Date: 08/07/09