Piedraont Aviation News - Page 3
Friday, September 14j 1945
5. V/ith the airplane in horizontal
flying position, you should next
balance the scales under the left
and right front wheel and tailwheel
and take the reading of the scales.
From this reading you must subtract
the weight of anything which had to
be placed on the platform of the
scales to chuck the front wheels or
to raise the tailwheel. The weight
which has to be subtracted is called
TARE. SCALE READING minus TARE is
the NET VffilGHT. The net weight of
the left front wheel corresponds to
Wl as used in our previous problems.
The net weight of the tailwheel
corresponds to W2»
6. Point F of our theoretical prob
lems is the location of the center
of gravity. Center of Gravity is
defined as the point about which a
body vi/ould balance in any position*
To find this point we procoed as
we did in our previous problems.
Multiply the distance botwoon the
front wheel axle and the tailwheel
axle by the tailwheel net weight and
divide this product by the empty ■
weight of the aircraft. The aircraft
empty weight is found by adding the
left and right front wheel net
weights and net tailwheel weights.
The result thus obtained is the
distance of the center of gravity
from the front wheel axle.
Let us work a problem:
Find the location of the center of
gravity from the front wheel axle
using the following data:
Net weight of left front wheel is
372 lbs., right front wheel 378 lbs.,
tailwheel 50 lbs.
Distance between front wheel axle
and tailwheel axle is 200".
Add weights: 372
378
50
800 lbs.
200 X 50 - 10000 2 12,5
800 " 800
The center of gravity location is
12.5" from front wheel axle.
Problem:
Find the location of the center
of gravity from the front wheel axle
using the following data:
Scale reading: left front wheel is
332 lbs., right front wheel 329 lbs,,
tailwheel 102 lbs.
Tare: left front wheel 5 lbs.,
right front vjheel 4 lbs,, tailwheel
46 lbs.
Distance, between front wheel axle
and tailwheel axle is 204"•
Answer ~ 16,14"