What happened
On September 23, 2007, a chartered Reims Aviation C 172 N was conducting a sightseeing flight with the pilot and one passenger. The flight departed from Sömmerda-Dermsdorf and initially proceeded over the Elgersburg area. During the return portion of the flight, near the Martinroda motorway bridge, the passenger noted a continuous decrease in engine RPM. The pilot did not perceive any sounds indicating engine malfunction.
Seeking an alternative landing site, the pilot diverted to a nearby grass airstrip at Niederwillingen. The aircraft landed on the short grass runway 24 with significant momentum and performed a go-around. While executing a tight left-hand circuit, the Cessna 172 N failed to maintain altitude and struck an open field at approximately 15:15 local time.
The investigation
The BFU examined the aircraft and the flight conditions. The investigation confirmed that the aircraft's center of gravity was within limits and the takeoff weight was approximately 890 kg, well below the maximum allowable mass. Meteorological conditions at the time of the accident were visual meteorological conditions (VMC) with visibility of approximately 8 km and light winds.
Post-crash inspection of the engine revealed that the throttle was set to full power and the mixture was set to rich. An endoscopic examination of the cylinders showed normal combustion chamber traces, and no further engine investigations were deemed necessary. The aircraft sustained heavy damage, including a deformed cockpit and a bent propeller blade, resulting in the total destruction of the airframe.
Findings
- The pilot and passenger sustained serious injuries.
- The primary factor in the loss of altitude during the circuit was the continuous reduction in engine RPM that occurred prior to the diversion.
- The aircraft was operated on a high-momentum landing and subsequent go-around on a short grass runway, which contributed to the inability to maintain altitude during the tight circuit.