Casualties unknown

1999-03-28: Mooney M20K (N12HW) — Medicine Bow, WY

Medicine Bow, WY, US

On March 28, 1999, a Mooney M20K (registration N12HW) was involved in an aviation accident near Medicine Bow, WY. Investigators recorded the probable cause as: A fluctuating turbine inlet temperature and resulting loss of engine power for undetermined reasons. Factors were the rough, unsuitable terrain on which to make a forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot experienced engine power loss during descent after leaning the turbine inlet temperature at 23,000 feet. Despite multiple descents and power reduction, the engine ran rough. A hard landing in a field damaged the right wing and landing gear. Investigation found no cause for the power loss.

Incident Overview

After reaching 23,000 feet mean sea level, the pilot leaned the engine's turbine inlet temperature (TIT). Approximately 5 to 10 minutes later, the TIT began to rise. The pilot requested and received clearance to descend to 17,000 feet. As the TIT continued to climb, he requested further descent to 12,000 feet and reduced power. At that time, the engine started to run very rough, popping and spitting, and not developing any power.

Emergency Descent and Landing

The pilot requested assistance for vectors to the closest airport. After locating the airport, he observed a tractor positioned in the middle of the runway. He selected a field approximately one-quarter mile east of the airport on which to land. The aircraft landed hard, damaging the right wing and landing gear.

Postaccident Engine Examinations

Several postaccident examinations of the engine were performed. Fuel was observed in the engine and in the fuel tanks, and was present in each of the fuel injector nozzles. When the fuel boost pump was turned off, the engine surged. The engine-driven fuel pump was bench and flow tested, and no discrepancies were observed. A replacement turbocharger was installed on the engine and test run, but the engine continued to run rough and surge.

Investigation Conclusion

Nothing was found during the investigation to determine what caused the loss of engine power.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001205X00316. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.