Weight Shift Formula; Mac - ASA Electronics cx-3 User Manual

Problem: Given the information above, find the
GW and CG if the 150-lb passenger exits the
aircraft, and 50 lbs of fuel are added .
Solution: The #Items/RF is not changing, nor is
the empty weight of the aircraft, so you do not
need to review the first 2 items .
1 . To change the passenger
load, scroll up to ITEM 3 . Your previous entries
for this item will be displayed, and Remove will
be displayed to the right of ITEM 3 . Tap enter to
delete ITEM 3 .
2 . To change the fuel load, scroll down to the (Wt)
line for ITEM 4 . Press
+
to find the new fuel weight (230 lbs) . Scroll
down to Arm and tap enter (it will automatically
remember the previous value of 96 IN) . A new
moment for this item is calculated to be 22,080
LB-IN .
3 . Scroll to the Weight and Balance Totals . This
will display output only, accounting for the
weight/load changes:
Wt . . . . . . . . . 2,105 .00 LBS
Mom . . . . . . . 197,993 .00 LB IN
CG . . . . . . . . 94 .06 IN
◗
The amount of weight that must shift to move the
CG to a desired location may be found using this
function . This function can also be used to find
the change in CG or Arm from adding or removing
weight .
and tap enter
5 0
◗
Large aircraft operations often require the CG be
expressed as a percent of the mean aerodynamic
chord (%MAC) . This function calculates the %MAC
given the CG, the length of the mean aerodynamic
chord (MAC), and the leading edge of the mean
aerodynamic chord (LMAC) .
– 17 –

WEIGHT SHIFT FORMULA

Problem: Find weight of the item (Item Wt) that
must shift to move the CG to a desired location,
given:
1 . Total weight, 7,500 LBS
2 . Change in CG, 1 IN
3 . Distance weight is shifted, 120 IN
Solution: Press the key . Select the Weight
W/B
Shift Formula submenu . At Total Wt, press:
7 5 0 0 and tap enter to input 7,500
LBS, then
and tap enter to input 1 IN for ∆CG, and then
1
and tap enter to input 120 IN for
1 2 0
∆Arm .
The display will show 62 .5 LBS Item Wt .

%MAC

Problem: Determine the CG in percent of MAC
given:
MAC . . . . . . . 860 .2 to 1040 .9
CG . . . . . . . . 910 .2''
LMAC . . . . . . 860 .2''
Solution: Press , then slide to the %MAC
W / B
function and tap enter . Press:
1 0 4 0 . 9 -
and tap enter for the MAC .
The result should be 180 .7 IN . Then press:
9 1 0 . 2 and tap enter for the CG,
and then
and tap enter for LMAC .
8 6 0 . 2
The display will show 27 .7% for the CG in %MAC .
8 6 0 . 2