Synopsis
A Europa XS aircraft, registration G-CHOX, experienced an engine failure due to oil starvation caused by the engine oil filter working loose. The pilot executed a successful forced landing into a field of unharvested wheat. The reason why the filter worked loose could not be determined.
History of the Flight
On 10 August 2008 at 1500 hrs, shortly after takeoff from Sherburn-in-Elmet, while climbing through approximately 2,000 ft, the passenger commented on a smell of burning. Almost immediately, smoke appeared in the cockpit. The pilot checked the electrical system but found no anomaly. Oil became visible on the windscreen. The pilot turned back toward the airfield and transmitted an emergency call. Just before the engine stopped, the pilot selected a suitable field for a forced landing. A glide approach was made, followed by a successful landing in a field of unharvested wheat. The nosewheel sustained damage during the landing.
Inspection and Findings
Following the incident, inspection of the engine revealed that the oil filter had worked loose, allowing oil to escape under pressure. A strip examination showed that the engine had suffered seizure of a connecting rod big end, which caused extensive secondary internal damage, rendering the engine beyond economic repair. It was deduced that the seizure resulted from oil starvation.
The oil filter is screwed on and does not have any locking device. Detailed fitting instructions are provided in the engine maintenance manual. The UK distributor of the engine is aware of only one other case of an oil filter working loose on this engine type. In that previous instance, there was evidence that the threads had been damaged when installing the filter.
Probable Cause
The probable cause was engine failure due to oil starvation caused by the engine oil filter working loose.