SX-16 Nightsun
®
Searchlight System
Maintenance Manual
Document 031734-1/Revision A
031734-1 Revision B
January 27, 2014
o
Stake the bearings in place using a center punch to deform the metal at the outer
edge of the bearing to retain the bearing.
o
Stake each spacer in four places.
•
If the old arm has any fixed pins that are pressed in as Elevation stops, drill the new arm (if
necessary) so that you can press in the stop pins.
•
Make sure that the Azimuth axis Roll Pin is installed at the top of the Gimbal if this stop
configuration is used. Cover the Roll Pin hole if the new stop configuration will be installed.
•
Install the elevation Gearbox assembly. Apply Loctite
®
to the fasteners and tighten the screws
fully.
•
Before the Azimuth Gearbox is reinstalled, make sure that both Roll Pins are in good
condition and not cracked or loose. Replace them if there is any question about their
condition.
•
Reinstall the Azimuth Gearbox assembly on the new arm:
o
Note the orientation of the Azimuth Gearbox to make sure that it replicates the
position of the removed Gimbal arm.
o
Install spacers and washers as they were on the removed arm.
o
Tighten the Azimuth shaft hex nut to 50 to 60 foot-lbs of torque.
o
Install the safety wire to the screw head by the side of the hex nut.
•
Make sure that there is a service loop in the wire that goes down from the elevation motor so
that the Azimuth Gearbox can move freely in the Gimbal without ripping the wires out of the
connector.
o
To verify the length of the service loop, clamp the Azimuth Gearbox in a bench vise
with the arm assembly sticking straight up.
o
By hand, apply enough torque to the arms to cause the Azimuth clutch to slip. Drive
the arms through their entire range of motion (in each direction) until they hit both of
the stop Roll Pins.
o
Verify that the wires do not pull at the connector or where they enter the motor boots.
•
Remove the small hardware from the removed arm and reinstall it on the new arm. This
includes some rubber-lined one-hole wire clamps and the Wing Bolts that attach the
Searchlight to the Gimbal.
•
If the RTV silicone adhesive used to seal the wires into the connector boss is not in good
condition:
o
Touch it up, or remove the old silicone and replace it with new silicone.
o
Let the silicone cure for 8 hours before using the Gimbal.
•
Reinstall the Gimbal on the aircraft.
o
Connect the cable to the Gimbal and perform an electrical test to verify that it works
properly.
o
Check the condition of the Gimbal to aircraft safety cable. This cable must be sound
and installed before flight.
•
Reinstall the Searchlight on the Gimbal. Connect the Searchlight to Gimbal safety cable. This
cable must be installed before flight.
•
Connect the Searchlight electrical cable.
•
Turn the system on:
o
Perform a full functional test of the Gimbal.
o
Start the Searchlight and let it run for 1 minute.
o
Turn off the Searchlight, but leave the system on so that the fan can cool the lamp.
•
In the aircraft maintenance log, indicate that the Gimbal arm was replaced and the existing
Gearboxes were reused (or if they were replaced).
4.15 Gimbal Drive Motors Inspection Schedule
Permanent magnet DC gear motors supply input power to the final drive worm gear reductions in both
the Elevation and Azimuth Gearboxes. Because these motors have a limited duty cycle (they do not
operate for long periods or very frequently), any maintenance they require is usually the result of
Source: Spectrolab, Inc.
25
The document reference is online, please check the correspondence between the online documentation and the printed version.
