TM 55-2840-241-23
Section III. ABNORMAL FLIGHT MANEUVER INSPECTION
12-9. Hard Landing Inspection.
a. Replace the engine if landing forces ex-
ceed 10 g. Use the airframe condition to deter-
mine if the 10g force limit has been exceeded.
If the airframe landing skids and cross tubes
are deformed to a degree that the fuselage
touches (or shows evidence of having touched)
the ground, the 10g limit has been exceeded.
b. If the conditions of step a do not apply,
make an inspection of the engine for damage
as follows
(1) Check gearbox housing and flanges for
cracks. If cracks in the housing are suspected, refer
(2) Inspect magnetic chip detectors for
metal particle accumulation.
(3) Check engine mounting pads for cracks.
(4) Check air, oil, and fuel tube connec-
tions for tightness and leaks.
(5) Check all engine accessories for crack-
ed flanges, loose bolts and nuts, connections,
(6) Install vibration monitoring kit, tool
No. 171170-0104, in accordance with TM 55-
4920-243-15, and operate the engine on the
ground for 30 minutes. Check for vibration in
excess of the limits specified in table 10-1.
(7) Shut down and check the magnetic
chip detectors for metal particles.
12-10. Sudden Stoppage Inspection.
The following inspections must be ac-
complished whenever the main rotor or tail
rotor strikes a stationary object.
a. Inspect the engine mounts for cracks and
security. If stoppage was severe enough to
fracture an engine mount, send the engine to
overhaul. If cracks in an engine mount are
b. Check the magnetic chip detectors for
metal particles.
c. Inspect the compressor blades and vanes
for foreign object damage.
d. Inspect the engine inlet for foreign objects.
e. Motor the engine and check for unusual
noise.
f. Install vibration monitoring kit, tool No.
171170-0104, in accordance with TM 55-4920-
243-15 and operate the engine on the ground
for 30 minutes. Check that vibration is within
limits specified in table 10-1.
g. Shut down and check the magnetic chip
detectors for metal particles.
h. Reinspect the magnetic chip detectors
after eight hours of engine operation.
1 2 -
4 Change 23
to TM 1-1520-254-23, Technical Manual Aviation
Unit Maintenance (AVUM) and Aviation Inter-
mediate Maintenance (AVIM) Manual Nonde-
structive Inspection Procedure for OH-58
Helicopter Series.
and general condition. If cracks are suspected,
refer to TM 1-1520-254-23, Technical Manual
Aviation Unit Maintenance (AVUM) and Aviation
Intermediate Maintenance (AVIM) Manual
Nondestructive Inspection Procedure for OH-58
Helicopter Series.
If cracks are suspected, refer to TM 1-1520-254-23
Technical Manual Aviation Unit Maintenance
(AVUM) and Aviation Intermediate Maintenance
(AVIM) Manual Nondestructive Inspection
Procedure for OH-58 Helicopter Series.
suspected, refer to TM1-1520-254-23, Technical
Manual Aviation Unit Maintenance (AVUM)
and Aviation Intermediate Maintenance (AVIM)
Manual Nondestructive Inspection Procedure
for OH-58 Helicopter Series.
