Pilot Debrief

PACIFIC AEROSPACE CORP LTD 750XL near Raeford, NC — 2015-12-03

Final reportERA16LA059
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Date
2015-12-03
Location
Raeford, NC, USA
Airport
5W4
Aircraft
PACIFIC AEROSPACE CORP LTD 750XL
Registration
N216PK
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Descent

Probable cause

The pilot's failure to obtain the proper touchdown point and speed during a precautionary landing with the engine shut down. Contributing to the accident was an erroneous engine torque indication, which led the pilot to shut the engine down, for reasons that could not be determined during postaccident testing.

NTSB narrative

The commercial pilot of the single-engine turboprop airplane reported that he was preparing to release skydivers when he noticed that the engine torque indication was in the red arc. Specifically, the gauge was indicating a torque of 70 pounds per square inch (psi) when it should have been indicating about 25 psi; the maximum allowed torque indication was 64.5 psi. The skydivers jumped uneventfully. As the pilot was returning to the airport, the torque gauge was indicating 80 psi while the engine was at idle. At that time, the pilot decided to perform a precautionary engine shutdown and land with no engine power. During the landing, the airplane was fast and touched down about halfway down the 3,402-ft-long asphalt runway. The pilot applied heavy braking, but the airplane traveled about 1,000 ft beyond the departure end of the runway before coming to rest upright in a field with a collapsed left main landing gear. Two examinations of the engine did not reveal any preimpact anomalies or evidence of overtorque. A test of the torque-indicating transducer and gauge also did not reveal any anomalies. The examinations did reveal that an automotive-type wiring bundle was used to wire the torque transducer to the airplane's electrical system. Although it is possible that the wiring bundle could have caused an intermittent faulty torque indication, subsequent testing was unable to duplicate the problem. The airplane was manufactured about 10 years before the accident, and the torque meter manufacturer upgraded the wiring connectors about 4 years before the accident.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have continued to fly instead of shutting down the engine.

NTSB coding

Evidence available

  • Photos
  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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