Rotorcraft had an unsuccessful mast moment during landing at hospital resulting in a broken left windshield and dented main rotor.
Air Methods Corporation
Date: 13-SEP-22
Time: 16:19:00Z
Regis#: N987RH
Aircraft Make: EUROCOPTER
Aircraft Model: MBB-BK 117
Event Type: INCIDENT
Highest Injury: UNKNOWN
Flight Crew: 1 Unknown Injuries
Pax: 1 Unknown Injuries
Aircraft Missing: No
Damage: UNKNOWN
Activity: INSTRUCTION
Flight Phase: LANDING (LDG)
Operation: 91
Aircraft Operator: AIR METHODS
City: ROCKFORD
State: ILLINOIS
Allright, sports fans - can anyone explain what "an unsuccessful mast moment" is?
ReplyDeleteThe BK-117 has a rigid rotor system, so it wasn't mast bumping. It would take a lot of control input to have a blade contact the fuselage, I think. Hard landing?
Mast moment is a particular limitation for the BK-117. Due to the rigid rotor, any time the helicopter is in contact with the ground and cyclic is applied, it produces a bending moment on the mast(mast moment). This can also happen in flight if the helicopter is subject to low G flight. In that case, the blades and rotor immediate change flight path, but due to loss of G loading, the fuselage doesn't immediately follow. This can also produce high MMs. How it came to have damage to the blade and forward fuselage is a bit of a mystery if simply caused by a mast moment exceeds. Probably a hard landing, MM exceedance, and some damage.
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