On August 25, 1983, an Enstrom 280C (registration N999TP) was involved in an aviation accident near N. Hailey, ID. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter experienced a hard landing and rotor blade strike with the tail boom after the pilot allowed rotor RPM to drop below green during takeoff from a county road at 5,500 ft elevation. No mechanical malfunctions were reported.
Incident Overview
A helicopter pilot reported that during takeoff from a county road situated at an elevation of 5,500 feet, the rotor RPM was allowed to drop below the green arc. According to the pilot's account, the situation presented two options: either land the helicopter back on the road or continue flight down a slope to regain airspeed. The pilot chose to land on the road.
Sequence of Events
The rotor RPM had decelerated to the extent that the touchdown was hard, and subsequently, the rotor blades struck the tail boom. The density altitude at the time was approximately 8,000 feet.
Investigation Findings
No mechanical engine malfunctions were reported in connection with the incident.