What happened
On March 22, 2014, at 17:3/local time, a Cessna 205, registration EC-GQB, was performing a private flight from Villarrubia, Córdoba, to Ontur, Albacete. The aircraft was being used for skydiving operations. While cruising at approximately 8,000 feet, the engine suddenly lost power and oil pressure dropped. The cabin quickly filled with smoke and the smell of burning oil.
The pilot identified a suitable landing site in a cultivated field near La Donal, Yeste. During the emergency approach, the pilot successfully avoided power lines but had to descend steeply to reach the field. The aircraft made initial contact with the nose gear, which detached, and the main gear followed. As the aircraft taxied across the soft terrain, it struck an irrigation canal running perpendicular to the landing path, causing the aircraft to capsize and come to rest in an inverted position. The pilot and one passenger sustained two minor injuries and were able to exit the aircraft through a window.
The investigation
The CIAIAC investigation focused on the engine failure and the maintenance history of the aircraft. Investigators examined the engine, which featured a Continental IO-470-S engine. The inspection revealed significant damage, including holes in the crankcase and broken components. The investigation ruled out oil contamination, fuel issues, or errors in recent maintenance tasks, such as the oil change performed two days prior to the accident.
Engine teardown revealed that the failure originated at the connecting rod bearing number 2. While the lubrication system was not blocked, the bearing showed signs of extreme overheating. Investigators also noted that the engine contained non-original parts installed during a previous overhaul, and the aircraft's maintenance program had not been adjusted to account for the high-stress nature of skydiving operations.
Findings
- The primary cause of the engine failure was inadequate and ineffective lubrication at the connecting rod bearing number 2, likely caused by the degradation of the bearing which created excessive clearance.
- The failure of this bearing led to the breakage of connecting rod number 2, which subsequently caused the destruction of other engine components, including connecting rod number 1 and the magnetos.
- A contributing factor was the failure to reduce the time between engine overhauls, despite the aircraft being used for skydiving and the engine containing non-manufacturer parts, both of which are conditions specified in the manufacturer's Service Information Letter (SIL 98-9C) as requiring more frequent inspections.