SL0810-01b2.doc Page 1 of 3 

# Nightsun ® 

# XP Searchlight Safety and Service Bulletin # SL 0810-01

Amendment # 2 Date:09/24/2010



### Subject: Gimbal Azimuth Top Hex Nut

Affected Products: Nightsun ® XP Gimbal Assemblies (See Exhibit A for specific part numbers) used on Nightsun ®
XP Systems, including In Flight Change Over (IFCO) equipped systems.



### WARNING: TO AVOID A POTENTIALLY DANGEROUS SITUATION WHICH COULD CAUSE PROPERTY DAMAGE, ENSURE THAT THE
GIMBAL ASSEMBLY IS INSPECTED AND / OR REPLACED AS
DESCRIBED IN THIS BULLETIN.

Dear Nightsun ® XP Searchlight Product User:

Under certain conditions, the Gimbal’s Azimuth Top Hex-Nut may become loose. The Gimbal’s Azimuth Top Hex-Nut is located internal to the Gimbal under the top Shroud Cover in the dovetail mount location. A loose nut could cause; a gap between rubber edging of the top Shroud and the Gimbal frame; degradation of pointing accuracy and stability performance; and pose excessive

vibration on the aircraft. If the nut were to entirely disengage, the Searchlight/Gimbal could potentially disconnect from the aircraft and remain attached solely by the internal cable harness.Spectrolab, Inc. Safety and Service Bulletin # SL 0810-01 dated 08/12/10
Amendment # 2 dated 09/24/10

SL0810-01b2.doc Page 2 of 3 What you should do: Perform the inspection procedure described in this letter daily.

1. Ensure the Searchlight/Gimbal is vertically mounted to a fixed location.

2. Visually inspect the Gimbal for a gap between the Top Shroud rubber edging (P/N 033381) and the Side Covers (P/N 033286). When the Gimbal’s Azimuth Top Hex-Nut is properly fastened, the edging should be in physical contact with the Side Covers.

3. Try to move the Searchlight laterally (reference figure below). No gap should appear between the Top Shroud rubber edging (P/N 033381) and the Side Covers (P/N 033286) and no play should be felt.

4. If a discrepancy is encountered, remove the system from the aircraft and return to Spectrolab immediately for compliance updates described in the Corrective Action section of this letter. If a discrepancy is not encountered, please contact Spectrolab to schedule the compliance updates

.

Spectrolab, Inc. Attn: ILS Repair Station

12500 Gladstone Avenue Sylmar, CA 91342-5373 (818) 898-2807

Rubber edging should be making

contact with Side Cover and a gap

should not be

p resent here Gap should not appear when pressure is applied on the

Side Covers when trying to create

side-to-side

motion from

either side.Spectrolab, Inc. Safety and Service Bulletin # SL 0810-01 dated 08/12/10
Amendment # 2 dated 09/24/10

SL0810-01b2.doc Page 3 of 3 Corrective Action: To prevent the Gimbal azimuth top hex nut from coming loose a design change introduces two positive locking mechanisms. In addition to a torque value of 120-140 ft-lbs applied to the nut and Loctite® 262 applied to the threads of the shaf t, the nut will have two locations for safety

lock wire.

In order to track all Nightsun® XP gimbals that are in conformance the Gimbals modified, as described above, will be re-identified as either 033295-3 or 033295-4 (white light and IFCO light, respectively). A new revision will be assigned to the top level system part numbers, specified in Exhibit A, reflecting the modified and compliant Gimbal.

Exhibit A – Affected System Part Numbers

System P/N Nomenclature Affected Revisions

033338 Nightsun® XP Searchlight System D and prior 033338-3 Nightsun® XP Searchlight System D and prior 033338-4 Nightsun® XP Searchlight System D and prior 033704 IFCO Nightsun® XP Searchlight System C and prior 033704-1 IFCO Nightsun® XP Searchlight System C and prior

For questions on this Service Bulletin or to return the system, please call our Customer Service Department at 1-800-936-4888 for instructions and/ or a Return Material Authorization (RMA)

number.

Emilio Quezada

Director of ILS Operations Spectrolab, Inc. (A Boeing Company)