Pilot Debrief

RYAN NAVION A near Torrington, WY — 2011-07-25

Final reportWPR11LA346
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Date
2011-07-25
Location
Torrington, WY, USA
Airport
TOR
Aircraft
RYAN NAVION A
Registration
N4911K
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Descent

Probable cause

The carburetor’s failure to meet its operating limits at the low range, which resulted in a loss of engine power when the pilot reduced power for landing.

NTSB narrative

The pilot reported that he leaned the mixture while en route, but could not find the peak performance. He set the mixture control to what he thought it was appropriate for 5,000 to 6,000 feet altitude. As he entered the landing pattern at his destination, he lowered the landing gear and prepared for landing. As he reduced the throttle position, the engine lost all power, and the descent rate increased. The pilot determined that the airplane would not glide to a runway and maneuvered to an open area. The airplane touched down hard, and the landing gear collapsed. The airplane sustained substantial damage to the firewall and fuselage. Postaccident examination of the airframe and engine revealed no mechanical malfunctions or failures that would have precluded normal operation. The carburetor was removed and connected to a test cell. The unit was found out of limits at the low end of its operating range. Thus, with the fuel mixture leaned and a subsequent reduction in the power for landing, a temporary disruption of the fuel flow caused the engine to sputter and lose power.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have maintained richer mixture to prevent engine power loss.

NTSB coding

Evidence available

  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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