Weighing; Calculated Weight - Thrush Aircraft S2R-R1340 Maintenance Manual

WEIGHING

Calculated Weight

The weight and center of gravity (C.G.) of
the airplane as it left the factory is supplied
with all the other paperwork.
Slight changes to the aircraft that do not
significantly alter the weight or C.G. can be
ignored, but judgment must be used when
doing so. A change weighing a pound in
the aft fuselage may be more significant
than a 5# change under the cockpit.
For changes that do significantly affect the
weight or C.G., the new empty weight and
C.G. can generally be calculated and
logged in the log book. To do this you
must know the weight change (+ for
added, - for subtracted) and its distance, in
inches, from the aircraft datum (wing
leading edge), "+" being aft of the datum
and "-" being forward.
2-4
THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
LEVELING LONGERON,
LEFT SIDE
Figure 2-1: Tie Down and Jack Points
*NOTE*
Center of Gravity (C.G.) location
is NOT the same as fuselage
station.
The existing empty weight and C.G.
produces a moment by multiplying the two
together, and all three should be logged.
Changes to the aircraft will also have a
weight and location for their C.G., which
will give their moment when multiplied
together.
To determine the new empty weight, the
existing weight and the weight change are
totaled. To find the new C.G., the existing
moment and the moment change are
totaled and this new moment is divided by
the new empty weight.
Effective 01/01/08