Pilot Debrief

DOUGLAS TA-4K near Las Vegas, NV — 2016-08-18

Final reportWPR16FA166
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Date
2016-08-18
Location
Las Vegas, NV, USA
Airport
LSV
Aircraft
DOUGLAS TA-4K
Registration
N140EM
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Approach

Probable cause

Foreign object debris in the engine's main fuel control unit, which restricted fuel flow and subsequently resulted in the loss of engine power. Contributing to the accident was the installation or addition of an extra seal during the main fuel control unit rebuild.

Contributing factors

Contributing to the accident was the installation or addition of an extra seal during the main fuel control unit rebuild.

NTSB narrative

The pilot of the experimental turbojet airplane, the lead airplane of a flight of two, was returning to the airport after providing combat training support. He led the formation to the overhead pattern, and shortly after the break to downwind, the engine lost power. The engine did not respond to throttle movements. The pilot started a turn toward the airport; however, he realized that he was unable to make the runway, so he turned left away from the runway toward a field and then successfully ejected from the airplane. The airplane subsequently struck terrain and was consumed by fire. No anomalies were noted during the initial airframe and engine examination that would have precluded normal operation. However, examination of the main fuel control (MFC) revealed foreign object debris (FOD) from a nonmetallic material inside the MFC unit. The material was identified as a nylon 6/6 material that was consistent with other seal material in the unit. However, all similar seal material inside the MFC was at its expected location. Further, the flow path made it unlikely that any nylon 6/6 material within the MFC could have migrated from known sources during the postimpact fire to where the FOD was located. Additionally, it was unlikely the nylon material was deposited into the MFC after the accident because examination of fuel components downstream of the MFC revealed no anomalies, obstructions, or nylon material. The MFC was rebuilt about 17 years before the accident, and the airplane had flown about 425 hours since then. It is likely that the FOD was part of an extra seal that was inadvertently installed or fell into the unit at the last maintenance overhaul. Subsequently, the FOD in the MFC eventually became positioned in such a way that restricted fuel flow and caused the loss of engine power.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted the approach after initial engine power loss.

NTSB coding

Evidence available

  • ATC audio
  • Video
  • ADS-B / radar
  • Photos
  • 29 docket documents
View NTSB final reportView NTSB docket

Docket documents29

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