Face Mounted Instruments Removal And Replacement; Cluster Mounted Instruments Removal And Replacement; Directional Gyro - Piper PA-24 Comanche Service Manual

PIPER
COMANCHE SERVICE MANrAL
II-I R. Removal And Replacement Of Face Mounted Instruments.
•
11-19. General. Since all
instruments
are mounted in a similar manner. a description of a
t~
pical f1:mIH al
and installation i, pr ovided as a guide for the removal and installation of the instruments. Special carl.'
should be taken \\ hen any operation pertaining to the instruments is performed.
a. Remme the instrument access panel by removing the retaining screws and lifting off the panel.
b. Remove
the face panel by removing the screws from around the perimeter of the
panel.
C.
With the face panel removed. the mounting screws for the individual instruments \\ ill he cxpovcd.
Remove the connections to the instrument prior to removing the mounting screws of the instrument to he
removed.
~OTE
Tag instrument connections for ease of installation.
d.
Insta lIat ion of the instruments wi II be in the reverse given for rernova I. After the installa tion
I'
completed and before replacing the instrument access panel. check all components for
sccunty
and
clearance of the control column.
II-~O.
Removal And Replacement
Of Cluster Mounted Instruments.
II-~I.
General. A cluster. located on the instrument panel. contains individual instruments.
Removal
01
these instruments can be accomplished by the following procedure.
a.
Remove
the instrument access panel by removing the retaining screws and lifting off the p a n e
h. Remme the face panel by removing the screws from around the perimeter of the panel.
c. With the face panel removed. the clear plastic cover on the cluster assembly will be exposed
Remme this cover by removing the two center mounting screws.
d. Remove the connection to the individual instrument to be removed and remove the instrument
from the cluster assembly.
e. Replace instrument in the reverse order of removal. Check all mountings and connections for
secunty.
II-~~.
Directional Gyro.
11-~3.
General. The directional gyro is a flight instrument incorporating an air driven gyro stabilized in the
vertical plane. The gyro is rotated at high speed by lowering the pressure in the air tight case and
simultaneously allowing atmospheric air pressure to enter the instrument against the gyro buckets. Due
to
gyroscopic inertia. the spin axis continues to point in the same direction even though the aircraft yaws to
the right or left. This relative motion between the gyro and the instrument case is shown on the instrument
dial \\ hich is similar to a compass card. The dial. when set to agree with the airplane magnetic compass.
provides a positive indication free from swing and turning error.
ISSt'ED: 8/18/72
3G5