Casualties unknown

1987-09-06: Bell 47G3B1 (N38CD) — AL Avn & Technical College — Enterprise, AL

Enterprise, AL, US

On September 6, 1987, a Bell 47G3B1 (registration N38CD) operated by AL Avn & Technical College was involved in an aviation accident near Enterprise, AL. Investigators recorded the probable cause as: The instructor pilot's delayed application of power to arrest the autorotative descent, which resulted in an inability to recover before ground impact. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During a routine practice autorotation, an instructor pilot delayed applying power to arrest the descent, leading to a crash despite no mechanical issues and both pilots being qualified.

What happened

The accident occurred during a training flight involving two certified flight instructors. The crew was conducting a practice autorotation, a standard emergency procedure used to land a helicopter safely after an engine failure. During the maneuver, the instructor pilot responsible for controlling the aircraft delayed the application of power needed to arrest the autorotative descent. A second pilot on board noted that the profile of the autorotation did not match previous successful attempts. Despite the lack of mechanical issues that would have prevented power recovery, the delay resulted in a crash.

The investigation

Examination of the flight crew revealed that both individuals were qualified and current as flight instructors. There were no reported aircraft problems or mechanical failures that would have hindered the ability to recover from the autorotation. The investigation focused on the timing of the power application during the critical phase of the maneuver.

Findings

The primary factor in this accident was the delayed application of power by the instructor pilot. This error prevented the timely arrest of the descent rate, leading to impact with the ground. The discrepancy in the autorotation profile reported by the other pilot suggests a deviation from standard operating procedures during the recovery phase.

Safety message

This incident highlights the critical importance of precise timing and adherence to established profiles during emergency procedure training. Instructors must ensure that power application occurs at the correct altitude and airspeed to guarantee a safe recovery.

Probable cause

The instructor pilot's delayed application of power to arrest the autorotative descent, which resulted in an inability to recover before ground impact.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X32000. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.