N5251B – Willey Rotorway Exec 90 – 2008-03-08 NTSB Accident Report

On March 08, 2008, a Willey Rotorway Exec 90 (N5251B) was involved in an incident near Westport, OK. All 2 people aboard were uninjured. The aircraft sustained substantial damage.

The National Transportation Safety Board determined the probable cause of this incident to be: An unsuccessful precautionary landing due to an electrical system malfunction.

The certified flight instructor and the student pilot were on an instructional flight to practice autorotations and simulated engine failures. About 45 minutes into the flight the instructor noticed the engine tachometer read lower than the rotor tachometer. The student pilot checked the battery voltage and said that it was "low". The instructor reported that the engine's fuel pump and ignition systems were not independent and he did not want to risk a downwind autorotation landing. When the instructor saw the rotor tachometer drop to 90 percent, he initiated an autorotation, assuming the helicopter had or was about to lose engine power. During the landing the left skid sank into the soft terrain and the helicopter subsequently rolled on to its side.

This incident is documented in NTSB report DFW08CA079. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N5251B.