Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 1 of 22

Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA AD 

2010-0183 Conformance 

SEE DOCUMENT ECR FOR APPROVAL SIGNATURES
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 2 of 22

CHANGE RECORD

REV AUTHORIZATION CHANGE DESCRIPTION APPROVAL 

NC SAUL VARGAS INITIAL RELEASE F. SANCHEZ 9/28/10 

 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 3 of 22

ITEM PART NUMBER QTY DESCRIPTION SOURCE 

1 033873 REV. B, OR LATER 1 

NUT, FLANGE 3⁄4-16UNF2B THREAD, WITH 

SAFETY WIRE HOLES 

SPECTROLAB 

2 017603 1 

NAME PLATE, (TO 

REIDENTIFY GIMBAL TO 

A 033295-3 OR -4 

CONFIGURATION) 

SPECTROLAB 

3 034377 AR 

MS35690-1230, 

MODIFIED 3⁄4”-16 HEX 

NUT (SAFETY WIRE 

HOLES). UNMODIFIED 

NUT EQUIVALENT TO 

MCMASTER-CARR 

91845A175. 

SPECTROLAB 

4 033732 1 OVERLAY, NAMEPLATE SPECTROLAB 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 4 of 22

The design change to the Nightsun® XP Searchlight System incorporated by this kit introduces a secondary 

mechanical positive locking mechanism to the Spectrolab Nightsun® XP 033295 series of gimbals that 

prevents the gimbal azimuth top nut from loosening and allowing the center shaft from rotating out. Briefly, 

Loctite® 262 is applied to the nut which is torqued to 120-140 ft-lbs and followed by safety wire. 

Once modified per this document, 034374, the Nightsun® XP gimbals will be re-identified as either 033295-3 

or 033295-4, white light and IFCO light, respectively. 

Note that a certain level of expertise in aeronautical work practices and knowledge is assumed of the personnel 

performing the work described below. 

Procedural Steps to rework 033295 series gimbals is mandatory and in a timely manner as prescribed by 

EASA and the TC/STC Holders. 

Implementation of this procedure should be less then three (3) man-hours. 

Reference 

1. Nightsun® XP Series Maintenance Manual, 033566-1 

!

Caution 

Personnel working with ESD sensitive devices should wear 

ESD safe garments. 

Procedural Steps to rework 033295 series gimbals. 

1. Remove the gimbal and searchlight system from aircraft. 

2. Separation of the gimbal from the searchlight is not a requirement but instead is left up to each 

installer based on their holding fixtures on hand. Refer to the Maintenance Manual for further 

instructions. 

3. Remove the applicable Dovetail from gimbal 

Reference Figures 1 through 3 of the Appendix: ParAvion dovetails are on the Nightsun® XP IFCO 

models, 033704 series, and Spectrolab dovetails are on the Nightsun® XP models (white light), 

033338 series. 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 5 of 22

4. Referencing Figures 4 and 5, remove the top shroud, taking note of its position relative to the rest of 

the gimbal. This is done in order to be able to properly reposition the shroud and spooler harness 

upon reassembly. 

a. Remove all screws under the Aircraft Adapter (5/16th and #10 screws) that attach the Shroud 

to the gimbal. 

b. Carefully unravel the spooler harness and set aside the gimbal, this harness will not be 

disconnected from the gimbal. 

5. Remove top nut 

An impact wrench maybe used to remove this nut, see Figure 6. 

This Kit contains the replacement nut. 

a. Note that there are two versions of this nut corresponding to two (2) different Upper 

Adapters (commonly referred to as Dovetail Adapter): 

i. 033293 dovetail adapter (1/4”-20): 

1. 3⁄4-16 Hex Nut is to be replaced with a 3⁄4-16 hex nut that has two (2) safety 

wire through holes. Item 3 of the Parts List, 034377. 

ii. 033673 dovetail adapter (5/16”-24): 

1. The 033873 Rev. B, or later, Flange Nut has two (2) safety wire through 

holes. Item 1 of the Parts List, 033873. 

6. Remove and save the washer shims, if any, located beneath the top nut (applicable to units equipped 

with the 1⁄4-20, 033293, dovetail adapter only). These washer shims must be reinstalled when the 

azimuth gearbox is ready to be reassembled. 

7. Remove the Dovetail Adapter and Round-off corner edge of inner legs (four places) 

a. Use a file, grinder, etc. to break edge of legs, see Figure 7 of the Appendix. The purpose is 

to provide a rounded surface for the safety wire to contour around. 

8. Reinstall the Dovetail Adapter 

a. Reinstall the washer shims previously removed (1/4-20, 033293 dovetail adapters only). 

b. Reinstall nut to hold the dovetail adapter onto the shaft. 

c. Apply Loctite® 262 and torque to 120-140 Ft-lbs. 

d. Install safety wire per standard practice, reference pictures 9 and 10 below. 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 6 of 22

e. CAUTION, when installing the safety wire, make sure to terminate the wire end away from 

any electrical connection and along the inner edge of the Dovetail Adapter legs (corner edge 

rounded off above). 

9. Reinstall the shroud and spooler harness. 

a. Rewind the spooler harness and place it over the gimbal in the same orientation as noted 

when removed. 

b. Test/verify proper alignment and winding direction of the spooler harness. 

i. Reference Figures 11 through 16 of the Appendix. 

ii. Rotate shroud in one direction and then in the other direction. The spooler is 

installed correctly if the shroud freely travels approximately 170 degrees in both 

directions. If not, remove shroud to verify that the shroud was wound in the correct 

direction and that the windings are correct, repeat step 9.a. 

10. Reinstall dovetail and apply a sealing bead of RTV 103 around the perimeter of the dovetail to the 

shroud. 

Safety-wire, loop 

end on short side of 

Dovetail adapter leg, 

as shown 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 7 of 22

11. Verify proper operation of the gimbal/searchlight system per standard practice. 

12. Reinstall the Gimbal/Searchlight System on to the aircraft and verify proper operation per standard 

practice. 

13. Remove existing overlay and label for the gimbal, 033295-X series, and replace with new nameplate 

and overlay identifying the gimbal as either 033295-3 or 033295-4. 

a. Peel off the overlay and nameplate 

b. Clean area with Isopropyl Alcohol (IPA) 

c. Apply the new Nameplate and overlay to the gimbal in the same vicinity as the previously 

removed. Apply the overlay symmetrically over the Nameplate. 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 8 of 22

Appendix: Photos of Process Steps

Figure 1: Aircraft Adapter (dovetail) 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 9 of 22

Figure 2: Loosening of Aircraft Adapter 

Figure 3: Removal of Aircraft Adapter from Gimbal (Dovetail) 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 10 of 22

Figure 4: Lift Shroud from Gimbal 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 11 of 22

Figure 5: Note Winding Orientation of Spooler Harness 

Figure 6: Remove Nut Holding Adapter 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 12 of 22

Figure 7: Break Edges 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 13 of 22

Figure 8: Two Styles of Nuts with Safety Wire Holes

Figure 9: Flange Nut with Loctite® 262, Torque and Safety Wired 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 14 of 22
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 15 of 22

Figure 10: 033292 Adapter with 3⁄4-16UNF-2B nut and safety wire 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 16 of 22

Figure 11: Re-align Spooler Harness 

Figure 12: Placing Gimbal Shroud on Chassis 

ELECTRICAL SIDE

CONNECTOR 

INTERFACE 

BOX 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 17 of 22

Figure 13: Positioning Gimbal Shroud 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 18 of 22

• Figure 14: Rotate Gimbal shroud clockwise to verify the spooler harness has 

enough travel without damaging connection terminations. The limit of 

rotation will be approached as the spooler harness gets tighter. The shroud 

should be able to reach the position illustrated with the dashed line after 

rotating through the external connector(s) housing.
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 19 of 22

• Figure 15: Rotate the Gimbal shroud counter-clockwise to verify the spooler 

harness has enough travel without damaging connection terminations. 

• Figure 16: Rotate the Gimbal shroud back to center position so the Gimbal 

is in the bore sight looking position. Align the shroud holes with the threaded 

#8 screw holes and fasten the shroud using the #8 screws. 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 20 of 22
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 21 of 22

Figure 17: Installation of Shroud onto Gimbal and Verification of Proper Travel 
Nightsun® XP Searchlight System 

Kit and Procedure to Incorporate EASA 

AD 2010-0183 Prescribed Conformance, 

034374 Revision NC 

__________________________________________________________________________ 

Source: Spectrolab, Inc.

Page 22 of 22

Figure 18: Reinstall Dovetail; screws attaching shroud to gimbal and the Dovetail using the 5/16-24 screws