On April 20, 2003, a Robinson R-22 BETA (registration N2341Z) was involved in an aviation accident near Ardmore, OK. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during liftoff. A contributing factor was the inadvertent encounter of propeller blast from the other airplane starting at the time of takeoff. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During lift off, a helicopter unexpectedly moved forward, rolled over, and came to rest on its left side after a parked airplane behind it started its engine, creating an unanticipated tailwind.
Event Details
A helicopter was being prepared for flight when the pilot pulled it out of the hangar and positioned it facing north into a light wind. Behind the helicopter, an airplane was parked facing south. As the pilot began the lift off, the helicopter suddenly moved forward. A scraping sound was heard, and the helicopter rolled over, coming to rest on its left side.
Pilot Statement
The pilot reported that as the helicopter lifted off, the parked airplane behind it started its engine. The propeller blast from the airplane generated a tailwind that the pilot did not anticipate and could not compensate for. The unexpected tailwind caused the helicopter to become unstable, leading to the rollover.