Piper Comanche PA-24 Service Manual page 835

12-8. Rack-Mounted Avionics
For airplanes with modern updgraded instrument / avionics panels, some avionics may be rack mounted.
Rack Mounted Avionics are rack-mounted front-removable units generally secured to the instrument
panel tray/rack by a single jackscrew located in the center of their faceplate.
A. Removal
1. Insert an appropriate size (generally 3/32 inch) allen wrench into the jackscrew access hole in
the faceplate.
2. Unscrew the jackscrew in a counterclockwise direction.
3. Slide the avionics unit aft and out of the instrument panel tray/rack.
B. Installation
NOTE: Inspect the front of the panel-mounted avionics tray/rack to verify it is not significantly
inset from the panel. If so, correct the tray/rack installation before proceeding.
NOTE: The high insertion forces required to seat a unit with "high density" connectors tend to
limit the effectiveness of the first seating attempt. Accordingly, the following procedure
requires sequential applications of force, and subsequent tightening of the jackscrew, to
ensure all connectors seat properly.
1. Slide the avionics unit into the instrument panel rack and forward applying a moderate
insertion force.
2. Insert an appropriate size (generally 3/32 inch) allen wrench into the jackscrew access hole in
the faceplate and tighten to remove any slack, but do not try to "pull" unit into place with the
jackscrew.
3. Apply additional insertion force to front of unit.
4. Tighten jackscrew again.
5. Apply additional insertion force to front of unit.
6. Finish tightening jackscrew.
7. Ensure that unit bezel is "tight" against panel.
12-9. Linear Modular Connectors (LMD/LMS)
For airplanes with modern upgraded instrument / avionics panels, Linear Modular Connectors
(LMD/LMS) may be used to simply assembly and reduce production costs. Special tools are needed to
remove some modules in some installations. See Amphenol / Pyle publication LM-300 (LM-300-1)
available from:
http://www.amphenol-aerospace.com/ServiceInstructions.asp
XII - ELECTRONICS
PIPER COMANCHE SERVICE MANUAL
3H8
04/01/09