TM 1-1520-238-23
Change 4
2-273
2.77.
MAIN LANDING GEAR RIGHT SHOCK STRUT STRUCTURAL SUPPORT
REMOVAL/INSTALLATION – continued
e. Check guide pins for corrosion, pits, scratches, cracks, and looseness. None allowed. Replace pin (para
2.77A).
NOTE
Magnetic particle inspection is to be performed by a qualified inspector in accordance with MIL-
STD-410E or having received appropriate training from an ATCOM authorized instructor.
f. Perform magnetic particle inspection on support.
(1) Inspection should be concentrated from an area around the sharp radius at shaft base continuing up shaft
approximately 0.25 INCH.
(2) No cracks, grooves, pits, or scratches are allowed inside the 0.25 INCH critical zone.
(3) Connect ultraviolet light to power source and allow it to warm up 15 minutes before using.
(4) Position center of coil around mount shaft. Ensure bottom of shaft rests on inside surface of coil as close
to shaft base as possible. Use demagnetizer.
NOTE
Energize coil by pressing the hand/foot switch for 2 to 3 seconds.
(5) Steady coil and magnetize mount by energizing coil.
(6) De-energize coil and remove from mount.
(7) Check magnetic field strength of threaded end of mount. Use magnetometer. A minimum reading of 5
marks (7.5 oersteds) deflection +/–. Repeat steps f.(4) thru f.(7) if minimum reading is not achieved.
(8) Immediately after magnetizing check, apply generous amount of well mixed magnetic particle compound
to shaft. Concentrate around lower portion of shaft and base. Use magnetic inspection compound
(item 60A, App F).
(9) Allow compound to set on mount for one minute prior to illumination with ultraviolet light.
(10) Illuminate mount and check for cracks. Use ultraviolet light.
(a) If cracks are found, go to step f.(11) to de-magnetize mount. Discard mount in accordance with normal
supply procedures and submit a Category 1 deficiency report.
(b) If no cracks are found, go to step f.(11).
(11) De-magnetize mount.
(a) Position center of coil around mount shaft. Ensure bottom of shaft rests on inside surface of coil as
close to shaft base as possible. Use demagnetizer.
(b) While coil is energized, slowly remove coil from shaft and clear end by minimum distance of two feet.
(12) Check mount for residual magnetism. Use magnetometer.
(a) If indicator does not exceed two marks +/– (3 oersteds), go to step f.(13).
(b) If indicator exceeds two marks +/– (3 oersteds), repeat steps f.(11) and f.(12).
(13) Clean inspection area and ensure all magnetic inspection compound is removed (para 1.47).
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