Jabiru Aircraft
Pilot Operating Handbook
Model J230-D
Revision:
6
28/2/2020
Page 64
6.4 TRIM SHEETS (USING METRIC UNITS)
The trim sheets included below, when used correctly, provide a means of calculating the aircraft
weight and CG position without manual calculations. An example of using the sheet is included
for reference.
6.4.1
Index Units
The chart is b
ased on an aircraft “EMPTY WEIGHT TRIM INDEX” which is calculated using the
following formula:
Empty Weight Trim Index
=
{(Aircraft Empty Weight) * (Empty Weight Arm)}
1000
Example Trim Index Calculation:
Aircraft Empty Weight
=
360-kg
Aircraft Empty Weight Arm
=
155.6-mm aft of datum
Empty Weight Trim Index
=
(360 x 155.6) / 1000
=
56
6.4.2
Calculate Aircraft Weights
1-1
Use the Aircraft Empty Weight obtained from the latest aircraft weighing records to
enter the vertical “Aircraft Empty Weight Scale” on the lower right hand side of the
chart.
1-2
Move horizontally to the left into the next scale which is the “Crew Weight” Scale.
1-3
Move vertically downward one line on this scale for each 10-kg of weight that is placed
on the front seats, and mark a point.
1-4
Move horizontally to the left from the point made in Step 1-3 to enter the next scale
which is the “Baggage Weight” Scale.
1-5
Move vertically downward one line on this scale for each 5-kg of weight that is placed
in either Baggage Zone and mark a point
– i.e. if 10kg is placed in Zone A and 5 kg in
Zone B then move down 3 lines (15kg).
1-6
Move horizontally to the left from the point made in Step 1-5 to enter the next scale
which is the “Fuel Quantity” Scale and mark a point, This point is the “Zero Fuel Weight
Reference Point”
1-7
Move Horizontally to the left of the “Zero Fuel Reference Point” and Mark a “Zero Fuel
Weight Line” across the “Aircraft Trim Condition” Graph.
1-8
From the “Zero Fuel Point” on the “Fuel Quantity Scale” (marked in Step 1-6), move
vertically downward one line for each 10-
litres
of fuel being carried at the take-off
condition. Mark this “Take-Off Fuel Point” on the scale.
1-9
Move horizontally to the left, and mark a “Take-Off Fuel Weight Line” across the
“Aircraft Trim Condition” graph.
