Primary finding
Probable cause
the ground resonance encountered by the pilot.
Investigator assessment
Analysis narrative
The helicopter impacted terrain during landing after entering into a ground resonance condition..
Source record
Factual narrative
On May 3, 2000, at 1755 central daylight time, a Hughes 269C, N456EM, owned and piloted by a commercial pilot, received substantial damage on impact with terrain during landing at Aberdeen Regional Airport (ABR), Aberdeen, South Dakota. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 proficiency flight was not operating on a flight plan. The pilot reported no injuries. The local flight originated ABR at 1730. In a written statement, the pilot reported, "...When landing, a condition I recognized as ground resonance began to exist. I then put the collective down and the condition did not seem to improve so I tried to lift the ship off the ground but rotor speed too slow".