SZD-54-2
„Perkoz”
TECHNICAL SERVICE MANUAL
SECTION 9.
INSPECTION OF CONTROL
SURFACES BALANCE
Issue II
April 2014
Revision No. 2
May 2017
Allstar PZL Glider Sp. z o.o.
Doc No. 542.4.02
page 9.1
corrected
SECTION 9.
INSPECTION OF CONTROL SURFACES
BALANCE
Schemes of control surfaces balance inspection are presented in Figure 9
‒1.
Ailerons balance inspection should be carried out separately for each aileron.
Measurement results must be recorded in balance records, patterns are
provided in Section 18.
1. Weigh aileron, elevator or rudder and determine the mass
„m
i
” [lb].
2. Mount aileron, elevator or rudder rotatable on two hinges in such way that
movement resistance is as small as possible when deflecting.
NOTE:
Mount aileron and elevator on two hinges in a way to prevent
excessive elastic bending.
3. Calculate allowable value of balance force
„P
R-i
” with the following formulas:
a) for aileron
main
P
R-AC
= 0,1790
× m
AC
[lbf]
wingtip
P
R-AE
= 0,1296
× m
AE
[lbf]
b) for rudder
P
R-R
= 0,0635
× m
R
[lbf]
c) for elevator
P
R-E
= 0,0858
× m
E
[lbf]
Above formulas include use of [lb] as unit of mass and [lbf] as unit of force.
4. Determine the point of force
„P
ZM-i
” application according to dimensions presented
in Fig. 9
‒1. pos. A, B, C.
5. Measure the force
„P
ZM-i
” using dynamometer scaled in [lbf] as presented in the
figure, read the value. Aileron, elevator or rudder chord plane should be levelled.
6. Measured force value
„P
ZM-i
” compare with calculated according to formulas in
item 3. value
„P
R-i
” .
2
