CELIER
SERVICE MANUAL
Xenon 2
RST
Aviation
Weighing and Specifying the Position of the
Centre of Gravity
Chapter 6
6.4
Weighing and Specifying the CG Position by a Three-Scales Method
A method of three-scales put under the wheels of the undercarriage is more intelligible for
the users. When put on scales, the gyrocopter must be levelled by means of an accurate level held
on the upper flat surface of the tunnel inside the cockpit between the chairs. The gyrocopter can be
weighed both with the rotor fitted and without it. It is central for the accurate specification of the
position of the centre of gravity that the rotor head axis be set up precisely vertically.
The gyrocopter weight is equal to a sum of (net) indications of all the three scales (plus the
rotor weight provided it was detached when weighing the gyrocopter).
M = W
F
+ W
RL
+ W
RR
(+ M
R
)
The position of the centre of gravity along axis X is calculated from the following formula:
x
cg
=
W
F
× a + (W
RL
+ W
RR
) × b
W
F
+ W
RL
+ W
RR
where:
W
– gyrocopter weight
W
F
– weight indication under the front wheel
W
RL
– weight indication under the rear left wheel
W
RR
– weight indication under the rear right wheel
W
R
– rotor weight
a = 1740 mm – axis coordinate of the front wheel
b = 90 mm
– axis coordinate of the rear wheels
x
cg
[mm]
– coordinate of the centre of gravity of the gyrocopter
Caution
The theoretical values of dimensions a and b are stated above.
The values must be measured when weighing and insert the actual values into the formula.
The admissible range of the position of the centre of gravity of the empty gyrocopter is:
188 ÷ 212 mm
Page 6-4
Document no.: X2RST-001-PL
Edition 1
24 Aug 2009
Change no.:
