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ASN Wikibase Occurrence # 218698
Last updated: 13 June 2021
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Type:Silhouette image of generic RV4 model; specific model in this crash may look slightly different
Van's RV-4
Registration: N83SB
MSN: 1171
Fatalities:Fatalities: 0 / Occupants: 1
Other fatalities:0
Aircraft damage: Substantial
Location:Montrose, CO -   United States of America
Phase: Unknown
Departure airport:Olathe, CO (1CO4)
Destination airport:Olathe, CO (1CO4)
Investigating agency: NTSB
The commercial pilot departed on a local flight and began a 120-mph cruise climb. After the airplane cleared some high terrain, the pilot leaned the engine fuel-air mixture, but the engine began to operate roughly. The pilot enriched the mixture, and the engine began to operate smoothly but then lost total power. The pilot performed emergency procedures, which included an attempted engine restart. The pilot stated that he pumped the throttle twice and that the engine responded with “2 small bursts of 500-600 rpms,” but then there was no additional engine power. The pilot executed a forced landing to a nearby private airfield but was unable to reach the runway, and the airplane impacted terrain and farm equipment.
A postaccident examination of the airplane fuel system revealed no anomalies. The carburetor could not be tested because it was destroyed during the accident sequence. A postaccident engine examination showed no evidence of preimpact mechanical malfunctions or abnormalities. Thus, the reason(s) for the total loss of engine power could not be determined.

Probable Cause: The total loss of engine power for reasons that could not be determined because a postaccident examination of the engine did not reveal any mechanical malfunctions or failures that would have precluded normal operation.



Accident investigation:
Investigating agency: NTSB
Status: Investigation completed
Duration: 10 months
Download report: Final report

Revision history:

28-Nov-2018 14:46 ASN Update Bot Added

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