– 16 –
does not affect the arms or weights involved
in the calculation . An RF of 100 means each
moment is divided by 100 before the calculator
displays it or the operator enters it; this will be
taken into account when the total and CG are
computed . RF of 1 means the moment entries
will be taken at face value .
2 . Press and tap enter to set 1 as the
reduction factor .
3 . Slide to ITEM 1, tap enter . Input the information
for the first item .
Press and tap enter for aircraft
weight, then
and tap
enter for the aircraft moment . This results in
101 .40 IN for the aircraft arm .
4 . Slide to ITEM 2, and tap enter to provide the
inputs for item number 2 . Press
and tap enter to input the weight, then
and tap enter to input the arm for item number
2 . This results in a moment of 24,320 LB-IN .
5 . Slide to add ITEM 3 and tap enter to provide
the inputs for item number 3 . Press
and tap enter to input the weight, then
and tap enter to input the arm for item number
3 . This results in a moment of 11,250 LB-IN .
6 . Slide to add ITEM 4 and tap enter to provide
the inputs for item number 4 . Press
and tap enter to input the weight, then
and tap enter to input the arm for item number
4 . This results in a moment of 17,280 LB-IN .
7 . Slide to see the Weight and Balance Totals .
This displays output only, accounting for the
inputs in the items above . For this problem, the
outputs are:
Wt . . . . . . . . . 2,205 LBS
Mom . . . . . . . 204,443 .00 LB-IN
CG . . . . . . . . 92 .72 IN
◗
WEIGHT AND BALANCE
The CX-3 performs all of the calculations necessary
for proper aircraft loading . The first four items in
the Wt/Bal menu are used to define the moment
reduction factor (RF), enter weight (Wt), enter arm
(Arm), and obtain the moment (Mom) . An “ITEM”
is something that has an assigned weight and
corresponding arm and/or moment . Additional ITEMs
can be added as necessary . The steps are described
below in the context of solving a basic weight and
balance problem .
Standard weights used in aviation include:
AvGas . . . . . . 6 lbs/gal
Jet fuel . . . . . 6 .84 lbs/gal
Oil . . . . . . . . . 7 .5 lbs/gal
(
Remember: there are 4 quarts in a gallon
)
Problem:
Find the gross weight (GW) and center
of gravity (CG), given:
1 . Aircraft empty weight: 1,495 lbs weight,
151,593 lb-in moment
2 . Pilot and passengers: 380 lbs, 64’’ arm
3 . Rear-seat passenger: 150 lbs, 75’’ arm
4 . Fuel: 180 lbs, 96" arm
Solution:
Press the key .
1 . Select the Weight and Balance submenu . You
will define the parameters for the totals (weight,
moment, and CG) . An “ITEM” is a variable
with 2 of 3 known parameters such as weight
and arm, or weight and moment . The CX-3
can calculate 8 items for any one problem . If
you have more than 8 items, work 3 problems
(one with half the items; a second with the
remaining items; and a third with 2 items, using
the answers from the first 2 calculations) . You
are first prompted for the reduction factor (RF) .
Reduction factors are used with aircraft that
generate large moments for the purpose of
keeping the numbers a manageable size . It
1
1
4
9
5
1
5
1
5
9
3
3
8
0
1
8
0
1
5
0
6
4
9
6
7
5
CX-3
Flight Computer
W/B (E6-B FUNCTIONS)
W/B
