5-65 Hard Landing
The hard landing inspection is listed in two parts. Part 1 concerns yielding (bending) of
the cross tubes due to hard landing such as hovering autorotations or run-on landings that
do not apply side loads to the landing gear. Part 2 concerns hard landings that, in addition
to yielding of cross tubes, have yielding of steel tube frames or fuselage primary structure.
NOTE
Buckling and bent steel tube structure are evidence of side loads
on the airframe.
1. Yielding of cross tube due to hard landing with no side loads:
a. Perform tail rotor drive shaft runout per § 65-21.
b. Visually inspect main rotor blades for oil canning of skins and buckling. Inspect
and repair main rotor blades per §§ 62-40 and 62-50.
c. Check landing gear cross tubes for yielding beyond serviceable limit. Place rotorcraft
on level ground, push up on tail rotor gearbox and release, allowing rotorcraft to
settle, then measure from tip of tail skid to ground. If less than 38 inches, one or
both cross tubes must be replaced.
d. Inspect front seat structure for yielding. Visually inspect, thru vent holes in seat
bottoms, the internal box structure for any deformation. Inspect aft seat structure
for yielding.
2. If yielding of steel tube frame(s) OR fuselage has occurred, inspect rotorcraft as
follows:
a. Perform Part 1 inspection.
b. Verify no yielding or cracks in steel tube frames.
c. Visually inspect fuselage, landing gear attach points, and firewalls for buckling or cracks.
d. Dye penetrant inspect upper steel tube structure and all welded joints.
e. Visually inspect tailcone for buckling or loose rivets.
f. Visually inspect landing gear skid tube-to-strut attach points for bending and cracks.
g. Hard landings can be accompanied by tail skid strikes, tail rotor strikes, main
rotor blade strikes, etc. To inspect for these conditions, refer to the appropriate
instructions in § 5-60. Refer to § 53-11 for cabin repairs. Any cracks, yielding or
buckling in steel tube structure or tailcone are cause for replacement.
h. Replace parts as required.
i. Check for symmetry if there is evidence of buckling of the cabin assembly per
Figure 5-5. Position helicopter on a hard, level surface with the weight of the
helicopter settled on the skids. Measure and record distances of lines A, B, C, and
D. Verify the difference between lines A & B is not more than 0.30 inch and the
difference between lines C & D is not more than than 0.40 inch. If the difference
between lines A & B or C & D is greater than the limits given, the cabin assembly
must be returned to RHC for repair.
MAY 2015 Chapter 5 Inspections Page 5.47
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