Piper Navajo PA-31 Service Manual page 641

PIPER NAVAJO SERVICE MANUAL
10-7a. INSPECTION AND CHECKS OF INSTRUMENTS AND SYSTEM.
During the
regular inspection of the airplane or whenever an instrument or instruments
is changed or
serviced, the following inspection and checks should be made to the complete
system:
a. Inspect the pitot-static system for cleanliness, condition, security and operation
per
Advisory Circular No. AC 43-203A for aircraft operated in controlled airspace
under IFR
conditions. Aircraft not operated in controlled airspace should be tested
per Advisory
Circular AC 43.13-1A. Section 4 of Chapter 16.
b. Inspect the instruments for poor condition, mounting, markings, broken
or loose
and/or missing knobs, bent or missng pointers, and improper operation (where
applicable).
c. Check power-off indications of instrument pointers and warning flaps for
proper
indication.
d. Apply power and check for excessive mechanical noise. erratic or intermittent
operation, failure to indicate, sluggishness or indication of excessive fnction.
Note if the
erection or warm-up time is excessive, caging functions are normal, and warning
flaps and
indicating lights and test circuits are operable.
e. Note operation of instruments during engine runup. Check for intermittent
or
improper operation of any instrument.
f.
Inspect the complete system for general condition, apparent and obvious defects.
insecurity of attachments, tubing connections and pneumatic tubing for security,
leaks,
corrosion, cracks, bends and pinching and any evidence of chafing.
g. Check electrical connections and circuit breakers for proper size, security
and
condition. Check instrument lighting system for range of illumination, burned
out bulbs and
defective controls. Check wiring for chafing, excessive tension, improper support
or broken
lacing and ties.
h. Check instruments for evidence of overheating or contamination of equipment
by
foreign matter or water. Dust. dirt and lint contribute to overheating of equipment,
poor
ventilation and malfunctioning. Special attention should be given that ventilation
openings
in equipment housings are open and free from obstructing lint and dust.
10-8. TROUBLESHOOTING. For troubleshooting of the various instruments,
refer to
Table in this section. (For instrument marking of the various instruments, refer to
Pilot's
Operating Handbook.)
10-9. REMOVAL OF INSTRUMENTS.
a. The non-shock-mounted instruments located in the center and along the bottom
of
the instrument panel may be removed by the following procedure:
1. At the back of the panel, unscrew the electrical connector from the post light(s).
2. Disconnect the plumbing and/or electrical connector from the back of
the
instrument. Where two or more lines connect to an instrument, identify
each line to
facilitate reinstallation. Attach a dust cap or plug to each fitting.
3. Remove the post light(s) by turning off nut.
4. Remove the screws that secure the instrument in the panel cutout.
5. Remove the instrument from the panel.
b. The shock-mounted instruments may be removed by the following procedure:
1. Unsnap the forward side of the instrument panel cover and slide forward enough
to allow it to move from its attachment slot. Remove the cover from over the
panel.
2. Pull the control wheel that is at the opposite side of the instrument panel from
where the shock-mounted panel is to be removed, to its aftmost position and
secure with a
cord tied between the wheel and around the seat back.
Reissued: 10/12/79
INSTRUMENTS
INSTRUMENTS
3D3