Piper Navajo PA-31 Service Manual page 423

PIPER NAVAJO SERVICE MANUAL
3. Install the friction knob with washer on the end of the lever shaft at the right side
of the
pedestal.
4. Connect the engine control cables to their respective levers using clevis pins. Place washer
on
ends of clevis pins and secure cotter pins.
b. The switches may be installed on their mounting brackets by the following procedure:
1.
Connect the electrical leads to their respective switch terminals. (Refer to Electrical System
Schematic, Section XI, for wire installation.)
2. Place the switch and spacer block in its mounting bracket and install attachment screws.
It
will be necessary to swing the bracket of the other switch and spacer block forward
to install the
attachment screws. Install nuts on the screws and secure.
3. Position the pedestal cover plates on the pedestal, install screws and secure.
4.
Adjust the switches per Paragraph 7-39.
7-39.ADJUSTMENT OF GEAR WARNING SWITCHES. The gear warning horn switches
are installed in
the control pedestal, with each controlled by a throttle lever. Each switch actuates the
warning horn when
either or both throttles are reduced below 10 to 12 inches of manifold pressure. The
following is a
procedure for the adjustment of the gear warning switches:
a.
Ground Adjustment:
1. Start and run the engines with the propeller set for full increase RPM.
2. To set the throttle switches to actuate at a desired throttle setting, retard the throttles until
approximately five inches of manifold pressure is indicated above the desired in-flight pressure.
Mark the
throttle cover in some manner in relation to the throttle levers for the adjustment of the
gear up warning
horn switches.
3.
Shut down the engines.
4.
Set the throttle at the locations marked. With the adjustment screw on the switch bracket,
adjust each switch separately toward the actuator angle until the switch is heard to actuate.
(On airplanes
with an inactive switch, substituting for spacer block, adjust until the active switch is heard to
actuate.) The
adjustment screw may be reached by inserting a long screw driver through the travel slot
of the throttle
lever in the pedestal cover.
b. Horn Operational Check:
1. To check the horn operation, jack the airplane and retract the landing gear. With the master
switch on, retard either throttle until the gear up indicator horn sounds. Check the location
of the throttle
to the adjusting mark. The warning horn will operate when either or both throttles are retarded.
2.
With the warning horn operating, lower the gear to insure that the horn ceases to operate
when the gear is down and locked.
3.
Remove the airplane from the jacks.
c.
Flight Adjustment:
1.
Flight test the airplane to insure operation of the warning system when the gear is up and
power is reduced to the desired manifold pressure.
2. If the horn fails to operate at the desired settings, mark the throttles at the proper manifold
pressure and repeat the preceding adjustment procedure as described in Step a. The switches
may be
adjusted with the airplane in flight using caution not to let the presence of the screwdriver interfere
with
the operation of the controls.
Reissued: 10/12/79
LANDING GEAR AND BRAKE SYSTEM
2F21