Technical data

13773-001
8-20
Page 1
WEIGHING
1. DESCRIPTION
This chapter provides information necessary to properly weigh the airplane for any of the various mainte-
nance, overhaul, or major repairs which might become necessary. To obtain the expected flight perfor-
mance, flight characteristics, and flight safety, the airplane must be operated within the permissible load
and center of gravity envelope. If the airplane or its equipment is modified in a way that might influence its
weight or center of gravity, the empty weight and corresponding center of gravity must be re-measured
2. MAINTENANCE PRACTICES
A. Weighing the Airplane
(1) Preparation
(a) Perform the following prior to weighing the airplane:
(b) Inflate tires to recommended operating pressures. (Refer to 12-10)
(c) Service brake reservoir. (Refer to 12-10)
(d) Drain fuel. (Refer to 12-10)
(e) Service engine oil. (Refer to 12-10)
(f) Move crew seats to the most forward position.
(g) Place all control surfaces in neutral position.
(h) Verify equipment installation and location by comparison to equipment list.
(i) Level airplane. (Refer to 8-10)
(2) Weighing (See Figure 8-201)
(a) Acquire necessary tools, equipment, and supplies.
Note: Two scale of equal height must be used for the main gear wheels.
(b) Place scale under each wheel (minimum scale capacity; 500 pounds for nose wheel, 1000
pounds for each main gear wheel).
(c) With the airplane level, doors closed, and brakes released, record the weight on each
scale. Deduct the tare, if any, from each reading.
(3) Measuring (See Figure 8-201)
(a) Obtain measurement ‘x’ by measuring horizontal along the airplane center line (BL 0) from
a line stretched between the main wheel centers to a plumb bob dropped from the forward
side of the firewall (FS 100). Add 100 to this measurement to obtain left and right weighing
point arm (dimension ‘A’).
(b) Obtain measurement ‘y’ by measuring horizontally and parallel to the airplane centerline
(BL 0), from center of nose wheel axle, left side, to a plumb bob dropped from the line
stretched between the main wheel centers. Repeat on right side and average the mea-
Description P/N or Spec. Supplier Purpose
Scales - Any Source Weigh the airplane.
Tape Measure - Any Source Provide measure-
ment for arm calcu-
lation.
Plumb Bob - Any Source Aid in airplane
measurement.
30 Nov 2000