Piper Comanche PA-24 Service Manual page 807

PIPER COMANCHE SERVICE MANUAL
11·24 Removal And ReplaccmcnL Refer to Parqnph 11-15 of this secnon.
11·25 Troublcshooanl.
TABLE XI·II. DIIlECTlONAL GYRO INDICATOR
Trouble
Ca_
Remedy
Exc ...
drift
in either
Excessive vibn.rion with
Check shock mounts.
direction. ampliNde more than
0.006 inch.
Insufficient vacuum.
If
vacuum below 4.2 inch
hi ..
check for the followins'
a. Relief valve improperly
1.
Adjust.
adjusted.
b. Incorrect puge rudins. b. RecaJibrate.
c. Pump fa.ilure.
c. Repair or replace.
d. Vacuum line kinked or
d. Check and repa".
leaking. Check for collapsed
i.nner w&ll of hose
Defective insavment. Replace instrUment.
Dial Spins continuously. Defective mechanism.
RCJ>lacc.
11-26 Gyro Horizon.
11·27 GenenJ. The IYro horizon is essentially an air driven gyroscope rota tin! in
1
honzonta! plane and is
oper.ned bv the same
prinCipal
as the dlr'cctional gyro. Duc to the
gyroKOPIC
incma. the spm
L,,(LS
continues
[0
point in the vertical direction. providing a constant visual reference
[0
the atntudc of the
airplane relative to pitc:h and roll uis. A
bu
Kross me face of the indicator represents the horizon. A
mmiature adjustable airplane is mounted to the cue and aligning the miniature airplane to the norilon bar
simulates the alignment of the airpl&nc to the actUal horizon. Any deviation simulates the dC\'ianon of the
airplane from thC' truC' horizon. The gyro norizon is marked for different degrees of bank
11-28 Removal And Replac:cmenL Refer to Paragraph 11-18 of this section.
INSTRUMENTS
ISSUED: 8/18/72
3 G6