What happened
On 17 August 2009, a Colomban Cri-Cri MC-15, registration G-CDNJ, was performing left-hand circuits at Coonagh Airfield, Co. Limerick. While the pilot was descending from 1,000 ft to 500 ft in preparation for landing, the left engine suddenly ceased operation.
Following the failure, the pilot attempted to maintain flight by applying full power to the remaining engine and selecting a flap setting of 12. However, the aircraft's airspeed dropped rapidly from 180 km/h to approximately 110 km/h. Due to the low altitude, the pilot was unable to complete the planned approach to the runway and instead executed a forced landing into a field adjacent to the airfield. The aircraft struck rough, soft terrain, causing the nosewheel and right undercarriage to fracture. The aircraft sustained substantial damage, including broken landing gear and extensive damage to the wings, fuselage, and propeller. The pilot escaped the wreckage without injury.
The investigation
The AAIU investigation examined the mechanical state of the aircraft, the fuel used, and the regulatory status of the flight. Investigators found that the aircraft was being operated using Mogas (motor gasoline) rather than Avgas. While the fuel was approved for use, the investigation noted that the aircraft lacked a carburettor heat system to manage icing risks.
Furthermore, the investigation established that at the time of the accident, the aircraft did not possess a valid Permit to Fly or a valid maintenance release. Records indicated that maintenance for the aircraft had not been documented since its importation, and the aircraft was not officially released for flight by a qualified person.
Findings
- The engine failure was probably caused by carburettor icing.
- The use of Mogas increased the aircraft's susceptibility to icing, as the higher volatility of Mogas leads to greater temperature drops within the carburettor.
- The aircraft was not equipped with a carburettor heat system to mitigate such risks.
- The aircraft was operating without a valid Permit to Fly or a current maintenance release.