Overview
On 6 November 2007, a Cessna 206 (registration ZS-PFS) experienced an engine failure while on a ferry flight from Hoedspruit Civil Aerodrome (FAHT) to Nelspruit Aerodrome (FANS). The pilot, the sole occupant, performed a forced landing in an open field near Acorn Hoek, South Africa. The pilot was not injured, and the aircraft sustained no damage except for a flat oleo. The aircraft was later recovered to FANS.
Incident Details
The flight departed Hoedspruit at 1312Z. When abeam Acorn Hoek, the engine began to run roughly and subsequently failed. The pilot attempted to restart the engine but was unsuccessful. He notified FAHT approach of his intention to execute a forced landing. After selecting a suitable field, he landed safely. The pilot held a valid commercial pilot license, was 29 years old, and had 525.9 total flying hours, with 254.8 hours on the Cessna 206.
Meteorological conditions at the time included visibility of 3 000 m, surface wind from the southeast at 15 knots, temperature 23°C, dew point 12°C, and 7/8 cloud cover with an overcast at 2 500 ft AGL.
Investigation
The last mandatory periodic inspection (MPI) was performed on 16 June 2007 at 9 328.5 flying hours. The aircraft had accumulated an additional 58.0 flying hours since then. After the incident, the engine was visually inspected by an aircraft maintenance organisation (AMO) at FANS; no fuel leaks or defects were noted. The engine was ground-run while still attached to the airframe. According to the AMO, it started almost immediately and ran smoothly. At full power (2 650 RPM), and during magneto testing at 1 700 RPM, no adverse RPM drop was observed on either magneto. The engine operated satisfactorily with normal magneto drop.
The report notes five general possibilities for engine failure—fuel starvation or exhaustion, inadequate or no ignition, poor fuel-to-air mixture, human error, or engine component failure—but none could be conclusively proven. The engine's satisfactory ground-run and absence of defects prevented identification of a specific cause.
Probable Cause
The probable cause was in-flight engine failure, the cause of which could not be determined.