Pilot Debrief

Piper PA28R near Winter Haven, FL — 2019-05-04

Final reportWPR19LA136
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Date
2019-05-04
Location
Winter Haven, FL, USA
Airport
GIF
Aircraft
Piper PA28R
Registration
N2134T
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

A partial loss of engine power due to worn fuel valve O-rings, which allowed air into the fuel system and resulted in a forced landing to unsuitable terrain.

NTSB narrative

The instructional flight was in-bound to the initial approach fix to practice a simulated instrument approach when the engine began to fluctuate and sputter. The flight instructor switched fuel tanks and turned on the fuel pump to no avail. The airplane was unable to reach a nearby airport, so the flight instructor accomplished a forced landing in an open field. During the forced landing, the airplane’s left wing sustained substantial damage when the landing gear struck a rut in the field. Postaccident examination of the airplane revealed no pre-impact anomalies. During the first of several engine runs, the engine started uneventfully but subsequently surged and stopped. Pressure was applied to the fuel system and fuel was observed leaking out of the top two vent holes of the fuel selector. The fuel selector was subsequently bypassed, and the engine started and ran with no additional anomalies noted. The fuel selector was removed and examined. During a pressure test, when the fuel valve was positioned to the left or right tank position, a fuel leak occurred again from the vent holes. Subsequently, the fuel valve was disassembled to examine the housing, shaft, and four O-rings. No anomalies were observed to the housing or shaft. Microscopic examination revealed that two O-rings appeared to have frictional interactions with the inner surface of the housing bore, and the other two O-rings exhibited wear on the surfaces in contact with the inner surface of the housing bore. No additional anomalies were noted. The circumstances of the accident are consistent with air entering the fuel system where the fuel leaks occurred in the fuel selector valve. Air in the fuel lines would have interrupted the flow of fuel to the engine, resulting in a loss of engine power.

Analysis

Primary failure mode
Fuel management
First missed decision gate
Switching fuel tanks earlier could have prevented engine power fluctuation.

NTSB coding

Evidence available

  • Photos
  • 11 docket documents
View NTSB final reportView NTSB docket

Docket documents11

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