On April 20, 2002, an Enstrom F-28C (registration N51769) was involved in an aviation accident near Hot Springs, MT. Investigators recorded the probable cause as: The pilot's inability to adequately compensate for a sudden wind shift from headwind to tailwind gust during takeoff. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter near its maximum gross weight took off in variable winds. As it moved forward from a hover, a tailwind gust occurred. The pilot could not compensate, leading to impact and main rotor contact with the tail boom.
Sequence of Events
The pilot was performing a takeoff in a helicopter that was operating near its maximum certified gross weight. The winds during the takeoff were variable. As the helicopter began to move forward out of a hover, the wind direction shifted suddenly from a headwind to a tailwind gust. The pilot attempted to compensate for this unfavorable wind change but was unable to do so adequately. Consequently, the helicopter impacted the terrain. The impact force was sufficient to cause the main rotor to strike the tail boom.
Aircraft and Operational Conditions
The helicopter was at or near its maximum certified gross weight at the time of the event. The wind conditions were reported as variable, and the shift occurred just as the aircraft transitioned from a hover to forward movement. No further details about the specific wind speeds or other environmental factors were provided in the investigation source.
Outcome
The helicopter sustained damage as a result of the impact and the subsequent contact between the main rotor and the tail boom. The source does not specify the extent of damage or any injuries to occupants.
Probable cause
The pilot's inability to adequately compensate for a sudden wind shift from headwind to tailwind gust during takeoff.