Power loss, lack of CRM lead to accident

This May 2007 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Aircraft: Grumman S-2B.
Location: Cherry Point, N.C.
Injuries: 3 Serious, 1 Minor.
Aircraft damage: Substatial.

What reportedly happened: The aircraft was a retired military design owned by an aviation heritage group. The flight crew consisted of two pilots and a crew chief. The first pilot, who held an ATP certificate, had logged 13,500 total hours, including 11,000 in multi-engine airplanes, with 46 hours in the same make and model as the accident airplane.

The copilot, who held a commercial pilot certificate, had logged 6,200 hours, including 2,602 in multi-engine airplanes. He had eight hours in the same make and model as the accident airplane. The copilot was flying the aircraft at the time of the accident. The airplane was on approach for landing at an altitude of 1,100 feet MSL when there was a loss of engine power.

The crew chief pushed the throttles forward for full power. The pilot not flying asked the copilot which engine had lost power. The copilot replied that he was holding right rudder in. When there is a loss of power in a twin engine airplane, rudder is used to counteract adverse yaw created by drag from the “dead engine.” Thinking that the left engine had failed, the pilot not flying feathered the left propeller because this would reduce the drag caused by the windmilling propeller. This did not result in a reduction of drag as expected, so he unfeathered the propeller.

The flight crew did not comply with the memory items for engine failure, nor did they comply with the 11 “challenge and reply items” on the airplane’s checklist. The pilot flying was not able to maintain altitude and the airplane came down short of the runway. The airplane hit power lines, trees, terrain, and was destroyed in a post-crash fire ignited by the downed power lines.

Investigators determined that the left engine had been producing power at the time of impact. Examination of the right engine revealed a seized, inoperative magneto, which would have lead to a loss of engine power.

Probable cause: The flight crew’s failure to comply with the published emergency procedures following a loss of engine power on the right engine. The failure of a magneto in the right engine was a contributing factor.

For more information: NTSB.gov/ntsb/brief2.asp?ev_id=20070531X00668&ntsbno=NYC07LA107&akey=1.

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