Rally Pilot Operating Handbook
Copyright 2008, Rally Aircraft
Revision 4.1
18
4.1 INTRODUCTION
This section describes the procedure for establishing the basic empty weight
and moment of the airplane. Sample forms are provided for reference. Procedures
for calculating the weight and moment for various operations are also provided.
4.2 AIRPLANE WEIGHING PROCEDURE
a) Preparation:
1) Inflate tires to recommended operating pressure
2) Drain all fuel
3) Drain all oil
4) Raise flap to the fully retracted position
5) Place the aircraft level
b) Leveling:
1) Place scales under each wheel (440 lbs minimum capacity for scales)
2) Release brakes
3) Check aircraft level
c) Weighing:
1) Record the weight shown on each scale deducting the tare, if any.
d) Measuring
(ref. figure 4-1):
1) Obtain measurement “A” by measuring horizontally (along the airplane
center line) from a line stretched between the main wheel centers to a
plumb bob dropped from the firewall
2) Obtain measurement “B” by measuring horizontally and parallel to the
airplane center line, from center of nose wheel axle, left side, to a
plumb bob dropped from the line between the main wheel centers.
Repeat on right side and average the measurements.
Using weights from (L – R - N) and measurements from (B) the airplane weight
and C.G. can be determined by completing Figure 4-5. The basic empty weight may
be determined completing Figure 4-6.
4.3 WEIGHT AND BALANCE
The following procedure will enable you to operate your aircraft within the pre-
scribed weight and C.G. limitations.
To figure weight and balance, use the sample problem form, loading graph and
C.G. moment envelope as follows:
1. Take the basic empty weight and moment from appropriate weight and
balance records carried in your airplane and enter them in the column titled
“YOUR AIRPLANE” on the sample loading problem.