On December 10, 1991, a Mbb BO-105CBS (registration N750H) operated by Omniflight Helicopters, Inc. was involved in an aviation accident near DE Ruyter, NY. Investigators recorded the probable cause as: AN INFLIGHT COLLISION WITH TERRAIN AFTER THE PILOT EXPERIENCED SPATIAL DISORIENTATION. FACTORS RELATED TO THE ACCIDENT WERE THE NIGHT CONDITIONS, AND THE LACK OF VISUAL CUES. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.
A medivac helicopter cruising at night under overcast conditions suddenly entered a right turn followed by a descending left turn and impacted terrain. The pilot had a documented problem with night flying and navigation.
Accident Sequence
The medivac helicopter was cruising at an altitude of 2,700 feet (700 feet above ground level) when it suddenly entered a right turn of 95 degrees within 15 seconds while maintaining altitude. This was followed by a descending left turn of 60 degrees in less than 5 seconds. The helicopter impacted the ground in a skids-level, nose-down pitch attitude.
Conditions
The accident occurred at night over an unlighted area with overcast cloud conditions.
Pilot Background
Interviews and examination of company correspondence disclosed that the pilot had a documented problem with night flying and navigation.