Pilot Debrief

AIR TRACTOR INC AT 502B near Monroe, NE — 2015-08-27

Final reportCEN15LA389
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Date
2015-08-27
Location
Monroe, NE, USA
Aircraft
AIR TRACTOR INC AT 502B
Registration
N61267
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Maneuvering

Probable cause

Loss of propeller thrust for reasons that could not be determined, since examination of the airplane's engine, propeller, and associated accessories revealed no anomalies.

NTSB narrative

The commercial pilot was performing an aerial application flight when the airplane experienced a partial loss of engine power. The engine instruments showed that the engine was operating, but was producing less than idle power. The pilot applied full throttle with no effect. He subsequently turned the airplane into the wind, lowered the flaps, and when he heard corn hitting the bottom of the airplane, pulled the control stick full aft to stall the airplane. The left wing dropped and the airplane turned 90° as it impacted the ground. The engine continued to run until the pilot shut it down and exited the airplane. An examination of the airplane's engine, propeller governor, fuel control unit, and fuel pump revealed no anomalies. An engine data recorder showed an exceedance of the N1 upper limit, followed by a decrease in internal turbine temperature, N1, and propeller rpm, consistent with a lower output by the engine. The data were reviewed by the engine manufacturer, who concluded that the data were consistent with a feathered propeller; however, the reason for the propeller feathering could not be determined based on the available information.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted the maneuver upon first signs of engine power loss.

NTSB coding

Evidence available

  • FDR / data
  • 11 docket documents
View NTSB final reportView NTSB docket

Docket documents11

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