Jabiru Aircraft
Pilot Operating Handbook
Model J230-D
JP-FM-09
Revision:
0
12 April 2007
Page 32
4.4.2
Calculating the Operating CG Locations
2-1.
Take the calculated Empty Weight Trim Index and mark it’s position on the Aircraft
Index Units Ladder at the top of the sheet.
2-2
Draw a vertical line down from the point marked above to intersect with a sloping line
in the “Baggage Zone A” scale and mark this point.
2-3
Calculate the weight of the baggage in Zone A and round this value to the nearest 5-
kg.
2-4
Move horizontally to the right from the point marked in Step 2-2 one line for each 10-
kg of load calculated. (i.e. 10-kg = 2 lines) and mark a point at this location.
2-5
Draw a vertical line down from the point marked above to intersect with a sloping line
in the “Baggage Zone B” scale and mark this point.
2-6
Calculate the weight that will be placed in Zone B and round this value to the nearest
5-kg.
2-7
Move horizontally to the right from the point marked in Step 2-5 one line for each 5-
kg of load calculated. (i.e. 20-kg = 4 lines) and mark a point at this location.
2-8
Drop a vertical line down from the point marked in Step 2-10 to intersect a sloping
line in “Fuel Chart”, and mark a point at this location.
2-9
Continue the Vertical Line began in Step 2-8 down to intersect with the “Zero Fuel
Weight Line” drawn in Step 1-7. mark this point as the “ZERO FUEL Condition”
2-10
Move horizontally to the right from the point marked in Step 2-8 in the “Take-Off Fuel
Box”, one line for each 10 litres of take-off fuel, and mark this point.
2-11
Move vertically downward from the take-off fuel point marked in Step 2-10 to
intersect with the “Take-Off Fuel Weight Line” marked in Step 1-9. Mark this point
the “Take-Off Condition”
Note:
As the crew are located in the aircraft very close to the CG datum their index value -
weight x arm - is very low and so is not entered into the trimsheet. However, the weight of the
crew still has a strong effect on the aircraft’s CG position & this is accounted for by including their
weight in the aircraft weight calculations.
4.4.3
Allowable Loading Conditions
An allowable loading condition exists when both the “Zero Fuel Condition”, and the “Take-Off
Condition” fall with the area bounded by the Line in the Aircraft Trim Conditions Box.
For reference, the example below shows two 80kg people, 10kg in Baggage Zone A, 5 kg in
Baggage Zone B and 50L of fuel. The aircraft’s starting Index Unit is 56 at 360kg.
