Installation Of Gear Warning Switches; Adjustment Of Gear Warning Switches - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
switch and spacer block. First remove the nut from each screw, and allow the bracket of the other switch
and spacer block to swing full forward by turning the adjustment screw counterclockwise. Pull aft on the
switch bracket to be removed and push out the attachment screws.
3.
Disconnect the necessary electrical leads.
b. The switch mounting brackets may be removed by removing the control lever assembly as
follows:
1. Disconnect the engine control cables from the control levers by removing the connecting
clevis pins.
2. Remove the flush head screw at each side of the pedestal housing.
3. Remove the friction knob with washer from the right side of the pedestal.
4. Remove the cap bolts that secure the frame.
5. Pull the assembly from the pedestal housing.
6.
Remove the control keeper tube that holds the switch brackets in the control frame by
removing the tube attachment screws from each side of the frame.
7-40. INSTALLATION OF GEAR WARNING SWITCHES. (Refer to Figure 7-14.)
a.
The switch mounting brackets, as part of the control lever assembly, may be installed as follows:
1. Assemble the mounting brackets (switches and spacer blocks may be installed with
mounting brackets), tension springs and spacer washers in the control frame and secure with keeper tube.
Secure keeper tube in frame.
2.
Install control lever assembly in the pedestal housing and secure with cap bolts and screws.
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 7-41.
7-41. 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 screwdriver through the travel slot of the throttle lever
in the pedestal cover.
Reissued: 9/23/80 LANDING GEAR AND BRAKE SYSTEM
2F2