Engine failure and subsequent stall during mapping flight

No fatalities • Sumter, United States of America • Flight

A twin-engine aircraft experienced engine power loss and a subsequent stall during a low-altitude mapping mission, resulting in a crash in a field.

What happened

During a low-level mapping mission at approximately 300 feet above ground level, the crew of a twin-engine airplane was conducting routine flights. Two hours into the mission, the pilot, who was occupying the right seat, performed a fuel tank switch from the inboard tanks to the outboard tanks without notifying the copilot. Approximately 90 minutes later, while the copilot was acting as the pilot flying, the left engine experienced a surge and a loss of power.

In an attempt to address the emergency, the pilot initiated procedures for an engine failure in cruise flight, which included moving the fuel selectors back to the inboard tanks. However, power was not restored, and the aircraft began an immediate descent. The pilot assumed control of the aircraft as it lost altitude. Just prior to the impact, the copilot observed that both fuel quantity gauges indicated zero.

During the emergency landing in a field, the aircraft stalled near the ground. The right wing made initial contact with the terrain, followed shortly by an explosion of the right outboard fuel tank. Both the pilot and the copilot successfully exited the aircraft through the rear door. There were 0 fatalities and 0 injuries reported.

Findings

Investigation of the wreckage showed that neither engine was producing power at the time of impact. While the left outboard tank remained full, the left inboard tank was empty. The fuel crossfeed valve was found in the open position, and the left fuel selector valve was in the OFF position, with no fuel present in the lines leading to the gascolator.

It is believed that the engines were drawing fuel from the inboard tanks for the duration of the flight until they were depleted. The investigation suggests the pilot misconfigured the fuel valves during the mid-flight switch or during the emergency procedure. Because the fuel panel was positioned behind and between the seats, the pilot had to look away from the flight path to adjust the controls, and the lack of verbal communication meant the copilot was unaware of the initial change. The left engine lost power first, followed by the right engine shortly before the aircraft struck the ground.

Probable cause

The pilot likely misconfigured the fuel selector valves during a mid-flight tank switch or during emergency procedures, leading to fuel exhaustion in the active tanks.

Frequently asked questions

What happened in the 2020-08-01 Piper PA-31-310 Navajo accident near Sumter, United States of America?

A twin-engine aircraft experienced engine power loss and a subsequent stall during a low-altitude mapping mission, resulting in a crash in a field.

Were there any fatalities in the 2020-08-01 Piper PA-31-310 Navajo accident?

No fatalities were recorded in this accident.

What aircraft was involved and where did it happen?

The accident on 2020-08-01 involved a Piper PA-31-310 Navajo, registration C-GXKS, operated by Terraquest, at Sumter, United States of America.

What was the probable cause of the accident?

The pilot likely misconfigured the fuel selector valves during a mid-flight tank switch or during emergency procedures, leading to fuel exhaustion in the active tanks.

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