Pilot Debrief

BELLANCA 17-30A near Carson City, NV — 2017-03-01

Final reportWPR17LA072
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Date
2017-03-01
Location
Carson City, NV, USA
Airport
CXP
Aircraft
BELLANCA 17-30A
Registration
N39894
Category
Airplane
Highest injury
Serious
Fatalities
0

Probable cause

A total loss of engine power due to internal corrosion of the fuel manifold valve. Also causal was the pilot's decision to return to the runway following the loss of engine power shortly after takeoff, and his exceedance of the airplane's critical angle of attack during the turn, which resulted in an aerodynamic stall.

NTSB narrative

The airline transport pilot was conducting the airplane's first flight after about 1 1/2 years of inactivity and the completion of an annual inspection. A witness reported that the airplane took off normally, but the retractable landing gear remained extended. As the airplane neared the end of the runway, about 300 ft above ground level, the engine sounded as though it "decreased to idle." The airplane entered a right, 180o turn and descended rapidly before impacting the ground. During a postaccident test run, the engine operated normally at both idle and full power settings and during abrupt changes between idle and full power. However, it operated inconsistently at 2,100 rpm for about 30 seconds before stabilizing at that power setting. During this time, the fuel pump pressure fluctuated. Following the test run, the fuel manifold valve was disassembled, revealing rust on the screen, lower housing, and plunger, consistent with exposure to water. The diaphragm was removed and a small amount of fuel was found on the "dry" side of the valve; the vent extending from this section was examined and clear of debris. Examination of the airframe and engine maintenance logs revealed that the airplane flew a total of 73 hours and underwent 3 annual inspections in the previous 8 years. It is likely that water accumulated in the fuel system sometime during the airplane's prolonged periods of disuse, resulting in corrosion of the fuel manifold valve's internal components. Because the corrosion was internal, it would not have been detected without disassembly of the fuel manifold, which is not part of the annual inspection procedure. It is likely that this corrosion caused the manifold valve plunger to temporarily stick, which restricted fuel flow to the engine and resulted in the anomalous operation during the postaccident test run as well as the loss of power on the accident flight. Following the loss of engine power, the pilot initiated a turn back to the runway, during which the airplane exceeded its critical angle of attack and experienced an aerodynamic stall.

NTSB coding

Evidence available

  • 9 docket documents
View NTSB final reportView NTSB docket

Docket documents9

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