Casualties unknown

1990-10-03: Mooney M20K (N231AX) — Flagstaff, AZ

Flagstaff, AZ, US

On October 3, 1990, a Mooney M20K (registration N231AX) was involved in an aviation accident near Flagstaff, AZ. Investigators recorded the probable cause as: THE PILOT'S DECISION TO OPERATE THE AIRCRAFT WITH A KNOWN DISCREPANCY; INADEQUATE MAINTENANCE PROCEDURES; AND THE PILOT'S INFLIGHT LOSS OF CONTROL DUE TO SMOKE AND FUMES IN THE COCKPIT. 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 returned from an initial departure due to smoke, then borrowed tools to inspect the aircraft. After a second departure, the aircraft was seen trailing smoke and possibly fire, rolled inverted, and descended into trees. A fractured turbo clamp with intergranular corrosion was found.

Initial Events

The pilot had returned from an earlier departure due to smoke inside the airplane. He requested mechanic assistance but could not obtain it. He borrowed pliers from the FBO and inspected the airplane himself. Afterward, he returned the pliers and commented about the EGT probe to a line person.

Second Departure and Accident

Soon after the second departure, the airplane was seen returning toward the airport, trailing smoke and possibly fire. The airplane then rolled inverted and descended into trees.

Investigation Findings

The airport manager who responded to the scene located the exhaust tailpipe. A fractured turbo clamp was found at the wreckage. Metallurgical analysis determined that the cracking resulted from intergranular corrosion. Additionally, the turbocharger had been removed, repaired, and reinstalled on September 26, 1990.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X24477. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.