ALPHA Trainer Manual Final.pdf - Pipistrel

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ALPHA Trainer 4-5
Weight and balance REV. 0
Baggage and CG
The amount of baggage you can carry in the baggage behind the seats is limited by the centre of
gravity of the empty aircraft (pilots’ weight does not significantly influence c.g.) and by the MTOM.
To calculate how much the c.g. shifts because of added baggage into the solid baggage compartmet
or the baggage behind the seats use the following formula:
where:
CG
with. bags
=
( G · CG )+ G · L
G + G
total mm bags mm
total
( )
bags
Gtotal is the aircraft empty weight,
CGmm is the position of CG of empty aicraft in milimeters (mm),
Gbags is the weight of the baggage,
Lbags is the lever arm from the datum to baggage area (1160 mm).
Again, express the new c.g. in percentage of MAC:
where:
CG
( + bags )% MAC
=
CGwithbags
.
- R
MAC
( 292kg
· 287mm)+ 10kg · 1160mm
=
292kg
+ 10kg
316mm
- 43mm
100 =
897mm
( )
100 = 31.
6%
CGwith.bags is the position of CG now with bags in milimeters (mm),
R is the difference between wing’s leading edge and MAC’s leading edge (43 mm),
MAC is the Mean Aerodynamic Chord (897 mm).
= 316mm
We now have the data of c.g. of the sample aircraft with 10 kgs (22 lbs) of baggage. You can recalculate
the formulas using the weights and c.g. of your empty aircraft and the planned amount of baggage
for your flight.
CAUTION: The baggage weight limitations in this manual represent fool-proof limits for safe
operation, even without special c.g. calculation. However, the actual baggage weight limitation
is different of each individual aicraft and can be determined using the above formulas. The decision
of how much baggage to carry on a flight is the pure responsibility of the pilot in command!
WARNING! Always make sure that the baggage is placed fixed inside the baggage area.
Movements of baggage in-flight will cause shifts of centre of gravity!
WARNING! Do not, under any circumstances attempt to fly the aircraft outside the allowable
c.g. limits! Allowable c.g. range is between 10.5'' mm and 14.5'' , measured from the wing's
leading edge backwards.
WARNING! Maximum takeoff weight (MTOM) MUST NOT, under any circumstances, exceed
1210 lbs (550 kg).