Engine failure and forced landing of Rans S10 near Fordingbridge

Casualties unknown • Near Fordingbridge, Hampshire, GB

A Rans S10 experienced an engine failure during a private flight near Fordingbridge, resulting in a heavy landing and subsequent aircraft damage.

What happened

On 31 July 1999, a Rans S10, registration G-BUGH, was conducting a private flight from Romsey to Henstridge. During the flight, the pilot noticed an unusual burning smell that did not appear related to engine heat. Shortly after, the Exhaust Gas Temperature (EGT) remained normal, but the water temperature reading dropped below the expected range, followed immediately by a total engine failure.

Due to the warm weather and high activity in the local heath and road areas, the pilot opted to perform a forced landing in a small nearby field. As the aircraft crossed a hedge, the pilot attempted to pull up for an uphill approach, but the left wing dropped. The resulting heavy impact caused the landing gear to collapse, pushed the engine fire wall back, and caused distortion to the fuselage around the landing gear mounts.

The investigation

Investigators examined the aircraft following the incident and determined that the engine had lost its cooling fluid. Although the pilot had verified fluid levels prior to the flight and ran the engine for a period before takeoff, a leak had developed. While no external leaks were visible during an initial inspection, investigators identified that the pipe connecting the expansion tank to the cooling system had become slightly porous.

Additionally, the investigation looked into the cockpit ergonomics. It was noted that the pilot's configuration made it difficult to access the magneto switches, which are located on the right side of the instrument panel. Because the pilot was wearing a shoulder harness, he was unable to reach the switches without unbuckling his straps, a factor that complicates emergency procedures during a forced landing.

Findings

  • The engine failure was caused by the loss of engine cooling fluid through a porous pipe connecting the expansion tank to the cooling system.
  • The heavy landing and subsequent structural damage were exacerbated by a wing drop during the attempt to flare for an uphill landing.
  • The cockpit layout presented an ergonomic challenge, as the magneto switches were inaccessible to the pilot while wearing a shoulder harness.

Probable cause

The engine ceased operation due to the loss of coolant through a porous connection pipe, leading to a forced landing in a field.

Frequently asked questions

What happened in the 1999-07-31 RANS S10 accident near Near Fordingbridge, Hampshire, GB?

A Rans S10 experienced an engine failure during a private flight near Fordingbridge, resulting in a heavy landing and subsequent aircraft damage.

What aircraft was involved and where did it happen?

The accident on 1999-07-31 involved a RANS S10, registration G-BUGH, at Near Fordingbridge, Hampshire, GB.

What was the probable cause of the accident?

The engine ceased operation due to the loss of coolant through a porous connection pipe, leading to a forced landing in a field.

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