On March 7, 1995, a Hiller UH-12C (registration N222TE) was involved in an aviation accident near Bonners Ferry, ID. Investigators recorded the probable cause as: ROTOR RPM WAS NOT MAINTAINED. FACTORS TO THE ACCIDENT WERE: INADEQUATE IN FLIGHT PLANNING/DECISION AND SUITABLE TERRAIN WAS NOT AVAILABLE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a student solo instructional flight, the pilot performed a pinnacle approach and hover at 3 feet, then transitioned to forward flight. Rotor RPM decreased, leading to loss of tail rotor authority. The helicopter landed hard and rolled onto its right side on a river bank. No mechanical failures were reported.
Event Summary
A student solo instructional flight ended with a hard landing and rollover on a river bank after the pilot experienced a loss of tail rotor authority. According to the pilot's report, the sequence began during a pinnacle approach. The pilot held a hover approximately three feet above the ground before transitioning to forward flight.
Sequence of Events
Immediately after transitioning to forward flight, the pilot observed that the rotor RPM began to decrease. The pilot noted that suitable terrain for a landing was not available, so he initiated a right 180-degree turn. During the turn, the rotor RPM continued to decay until tail rotor authority was lost. The pilot then performed a side slip maneuver toward the river bank. The helicopter subsequently landed hard and rolled onto its right side.
Additional Information
The pilot reported that there were no mechanical failures or malfunctions with the helicopter at the time of the accident. No further details regarding the aircraft, location, or injuries were provided in the source.