North American T28A N9862C accident near Ontario, Oregon

Probable cause

A total loss of engine power due to the improperly adjusted carburetor idle valve.

NTSB analysis

The pilot and one passenger were conducting a flight to test the landing gear. Following a low pass over the runway, the engine lost total power, and the pilot performed a forced landing to a field, during which he was fatally injured, and the passenger sustained serious injuries.

Postaccident examination of the carburetor revealed that, when the throttle arm was placed near the idle position, the internal idle valve was closed, which restricted fuel from flowing through the carburetor at lower power settings and likely resulted in the loss of engine power. It is likely that the pilot reduced the engine power during the low pass to a setting that would have allowed for the idle valve to close completely, thereby restricting the fuel flow. No additional anomalies were noted with the engine or airframe.

The airplane had not flown for about 8 years and had undergone maintenance for the previous 10 months before it first flew 6 days before the accident. One of the maintenance items performed included installation of a new carburetor. The mechanic who performed the annual inspection reported that he assisted in adjusting the idle setting on the carburetor. Whether any additional maintenance was performed on the carburetor before the accident flight could not be determined, and the engine logbook was not available for review.

Text from the NTSB. Open the NTSB docket for WPR19FA215 for the full record.