Helicopter impacts terrain during simulated autorotation training

Casualties unknown • Pontiac, MI, US

A helicopter crashed into terrain during a training maneuver after experiencing a total loss of engine power during the recovery phase.

What happened

During a training session conducted by a flight instructor, the pilot of a helicopter was performing a simulated autorotation. While attempting to recover from the autorotation, the aircraft experienced a total loss of engine power. This loss of power resulted in the helicopter impacting the terrain.

The investigation

Investigators examined the engine idle speed following the accident. The aircraft's checklist requires specific procedures to be performed at the end of the final flight of each day and prior to engine shutdown to ensure the engine idle speed is maintained within the range of 1,400-1,600 rpm. Investigation revealed that these required checks were not being conducted by the operator. Upon inspection of the engine after the accident, the idle speed was found to be only 700-800 rpm.

Probable cause

The failure to perform required engine idle speed checks at the end of each day, resulting in an improper idle speed that contributed to the loss of engine power during recovery from a simulated autorotation.

Frequently asked questions

What happened in the 2001-08-26 Hughes 269B accident near Pontiac, MI?

A helicopter crashed into terrain during a training maneuver after experiencing a total loss of engine power during the recovery phase.

What aircraft was involved and where did it happen?

The accident on 2001-08-26 involved a Hughes 269B, registration N9390F, at Pontiac, MI.

What was the probable cause of the accident?

The failure to perform required engine idle speed checks at the end of each day, resulting in an improper idle speed that contributed to the loss of engine power during recovery from a simulated autorotation.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20010904X01872. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.

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