On July 18, 1992, a Schweizer 269C (registration N280CA) operated by Pacific Shore Aviation, Inc. was involved in an aviation accident near Simi Valley, CA. Investigators recorded the probable cause as: THE COMPANY'S MAINTENACE PERSONNEL IMPROPER ADJUSTMENT OF THE AIRCRAFT'S IDLE RPM AND THE FAILURE OF THE INSTRUCTOR PILOT TO MAINTAIN ADEQUATE ROTOR RPM AFTER THE ENGINE FAILED. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During autorotation practice, an engine failure forced a hard landing, substantially damaging the helicopter. Post-accident testing revealed the engine could not maintain idle RPM.
Accident Sequence
A helicopter instructor pilot and a dual student were conducting autorotation training exercises. The maneuvers involved autorotative approaches terminated with power recoveries at a 3-foot hover. On the sixth autorotative approach, the helicopter's engine failed, leading to a hard landing that substantially damaged the aircraft.
Post-Accident Findings
Following the accident, an operational test was performed on the engine. The test determined that the engine would not operate at idle RPM, indicating a malfunction that contributed to the loss of power during the approach.
Pilot Background
The certified flight instructor (CFI) had logged a total of 154 helicopter flight hours, of which 9 hours were in the accident helicopter make and model. Additionally, he had accumulated 20 hours of helicopter flight instruction experience.