TB 1-1520-238-20-66
8. Inspection Procedures.
a. This task directs a special maintenance inspection of the BUCS subsystem. This requires a visual
inspection of each SPAD Assembly in the aircraft (8 places). This inspection focuses on the mounting security
and function of the SPAD micro switches. The proper function of the switches shall be determined by removing
the SPAD Shear Pins; manually engaging the BUCS mode (rotating the Mechanical Cam); and verifying
electrical continuity through both SPAD switches (2 per SPAD). Reference figure no. 2 of this TB for a
depiction of a typical SPAD Assembly.
(1) Perform a BUCS Self Test, I/A/W Reference c., pare 8-26, page 8-9. Follow message
prompts.
(2) Perform the DASE Interactive FD/LS Check (DASE02), I/A/W Reference b. task 4-2, page 4-5.
Follow the message prompts and/or any corrective action messages.
b. Copilot/Gunners Station SPAD Inspections:
c.
NOTE
Observe all task preconditions, notes, cautions and warnings or damage to the
personnel or the aircraft may result. Retain all fastening hardware for
reinstallation.
Inspect removed shear pins for straightness (bent/bowed) and deep material
scratches -- none allowed. Minor surface scratches along the pin shank are
permitted, as are tooling marks and gouges, resulting from the removal process
on the ends of the pin (head/taper).
CPG Directional SPAD
(1) Remove the 30mm Gun Barrel from the Gun Receiver I/A/W reference d., task 4-7-4, in
preparation for de-paneling.
(2) Gain access to the CPG's Directional SPAD Assembly by removing panel B60, L60 and
B65L (reference a., task 2.2). Refer to reference a., task 11.146 disconnect plug P118 to gain access to the
shear pin retainer.
NOTE
The following SPAD Switch inspection criteria is typical for all SPAD switches in
the aircraft. The tasks referenced throughout this procedure refer to TM 1-1520-
238-23 (reference a.), unless otherwise indicated. Use inspection mirrors and
flashlights as required.
If a shear pin(s) cannot be removed by conventional means after repeated
attempts from any of the SPAD Assemblies (CPG or Pilot), deliberately shearing
the shear pin is permitted. Ensure both ends of the pin are removed. Prevent
foreign object damage (FOD).
If either/both SPAD microswitches fail the following mounting security check or
electrical continuity test, contact the MDHC CFSR for optimized SPAD removal
and installation procedures.
(3) Visually inspect the SPAD microswitches (designated S1 & S2) for mourning security.
Confirm mounting security.
NOTE
The following inspector is for information and recording purposes only. If the
characteristics listed below are evident, or are not in evidence--these factors are
not cause for rejection of the SPAD Assembly.
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