Single Or Dual Attitude And Directional Gyro Installation With Deicer Boots - Piper Navajo PA-31 Service Manual

PIPER NAVAJO SERVICE MANUAL
10-18. DUAL ATTITUDE AND DIRECTIONAL GYRO INSTALLATION. The required
reading at the pressure gauge located in the right side of the instrument panel should
indicate 6.0 inches of mercury during single-engine operation at 2200 RPM and 5.5
.2 in.
hg. inches of mercury during multi-engine operation at 2200 RPM. Each engine should be
operated separately to determine if and which pressure regulator requires adjustment. There
is one regulator for each engine pump located in the right forward side of each engine
nacelle and a center regulator on the right upper side of the forward cabin bulkhead. (Refer
to Figure 10-3.) Adjustment procedures are as follows:
a. Remove the access plate to the regulator in the nacelle by removing the center
forward plate at the top of the nacelle. Access for the adjustment of the center regulator is
from the underside of the copilot's instrument panel.
b. Loosen the jam nut of the center regulator and turn the adjustment screw clockwise,
by hand, as far as possible. Note approximate number of screw threads exposed before
turning.
c. With one engine operating at 2200 RPM, check that the pressure gauge in the
instrument panel is indicating 6.0 inches of mercury. Should the reading be incorrect and
with the engine shut-down, loosen the jam nut of the regulator of the engine checked and
turn the adjustment screw clockwise to increase pressure and counterclockwise to decrease
pressure.
d. Repeat the preceding step for the other engine.
e. With engine shut-down,
turn the adjustment
screw of the center regulator
counterclockwise to the approximate position of the screw before check began.
f. Start both engines, operate at 2200 RPM and ascertain if the pressure gauge
indicates 5.5
.2 in. hg. inches of mercury. If incorrect, shut-down engine and readjust until
correct. Tighten all regulator screw jam nuts.
g. Check pressure reading through entire single and multi-engine range.
h. Reinstall access plates.
10-19. SINGLE OR DUAL ATTITUDE AND DIRECTIONAL GYRO INSTALLATION
WITH DE-ICER BOOTS. (Refer to Figure 104.)
a. Remove the access plate to the pneumatic system test gauge tap point by removing
the left aft plate at the top of the right engine nacelle.
b. At the pneumatic manifold in the left side of the nacelle remove the cap from the
tap fitting and install pressure gauge. An accurate gauge with a range from 0 to 20 psi with a
hose long enough to allow the face of the gauge to be observed from the cockpit is desired.
The tap fitting is three-sixteenth straight thread flared. (Refer to Figure 10-5.)
c. Operate one engine at 2200 RPM and check if the pressure gauge at the nacelle reads
6.0 psi. Should the reading not be within tolerance, shut-down the engine and remove the
forward access plate at the top of the nacelle. Loosen the adjustment screw jam nut of the
forward regulator of the dual regulators in the right side of the nacelle and turn the screw
clockwise to increase pressure and counterclockwise
to decrease pressure. Tighten
adjustment screw jam nut.
Reissued: 10/12/79
INSTRUMENTS
3D9