Jabiru J450, Руководство конструктора, Страница: 302 / 343

Jabiru J450 Constructors Manual
Testing>Weight and balance
Tuesday, April 6, 2010 302 of 343
Examples of calculation
Below is an example calculation showing typical values:
Item Weight
(kg)
Distance to Datum
(mm)
Moment
(kg/mm)
Nose wheel
75 - 780 - 58,500
Left main wheel 108 + 475 + 51,300
Right main wheel 108 + 475 + 51,300
Column totals: 291 Moment / Weight 44,100
Empty Aircraft Arm 151.55 mm aft of Datum
Empty Weight Trim Index : [(291 x 151.55) / 1000] = 44.1 .
Rebalancing the aircraft
You must now use the Load and Balance Worksheets in Section 6 of the Owners Manual to
test all of the likely loading scenarios for your intended operations and see if any fall outside
of the envelope.
For factory built aircraft we are required to use the CASA-approved standard passenger
weight (currently 86kg) to calculate loadings, but as you are the builder you may choose to
use the actual weights of yourself and your regular passenger(s) along with items that you
intend to carry with you, such as tie downs, toolkit, suitcases, camping equipment and so on.
If it seems possible that an intended loading could exceed, for example, the forward limit,
then you would need to consider adding some ballast to the rear of the aircraft.
If any rear ballast is required the preferred method is to add it in the form of lead shot mixed
with resin to the ventral fin. (Note: It is unusual to need forward ballast – if there is an
intended loading that would require forward ballast it will usually be very close to MTOW
anyway and should very probably be avoided all together.)
Assuming that rear ballast is required you would measure the arm of the ballast station/
location from the
Datum and calculate the weight of ballast required, adjust the calculations to
obtain a revised Empty Aircraft Weight , Empty Aircraft Arm and Empty Weight Trim Index
and then retest all of the likely loading scenarios for your intended operations and see if any
still fall outside of the envelope.
Once you are satisfied that the majority of the likely loading scenarios for your intended
operations will fall inside of the envelope, you may physically add the ballast and repeat the
weighing procedure and then record the revised values in the
Aircraft Empty Weight Record
in Section 6.2 of the Owners Manual.
This completes the Testing>Weight and balance task.
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