What happened
On September 20, 2008, at approximately 16:30 UTC, a VM-1 Esqual ultralight aircraft, registered EC-ZIE, was conducting a local leisure flight along the coast near Ovar, Portugal. The flight, which included a pilot and one passenger, proceeded normally until the aircraft passed near the village of Furadouro, when the engine suddenly ceased operation due to a progressive loss of oil pressure.
Recognizing the emergency, the pilot performed a 180-degree turn and prepared for an emergency landing on the sand at Praia do Furadouro. The pilot approached the southern area of the beach, choosing a section with fewer beachgoers. While attempting the landing, the aircraft struck the structural supports of beach stalls and a flagpole. The impact caused the aircraft to capsize and come to rest in an inverted position.
Because the occupants were trapped inside, the canopy had to be broken to allow for their escape. The passenger was uninjured, while the pilot sustained minor abrasions to the forehead from striking the canopy during the egress. The aircraft sustained damage to the left wing, the propeller, and the canopy.
The investigation
The GPIAAF investigation focused on the engine's lubrication system and the circumstances of the engine failure. Investigators examined the engine and found that the rubber hose connecting the engine to the oil radiator had disconnected from its metal fitting. This disconnection allowed the engine oil to be expelled into the atmosphere until the system was empty.
As the lubrication level depleted, engine temperatures rose significantly, leading to increased friction and the eventual seizure of the engine. The investigation also noted that the physical accessibility for securing this specific hose was extremely limited, and the type of clamp used was difficult to tighten properly and appeared to be of fragile material.
Findings
- The primary cause of the incident was the engine failure in flight, which necessitated an emergency landing on unprepared terrain.
- A contributing factor was the rupture of the engine oil line, which led to a total loss of lubricant.
- The design of the engine compartment made the oil line connection difficult to access, and the existing clamping mechanism was inadequate for ensuring a secure, permanent seal.
- Inadequate maintenance practices likely contributed to the failure of the connection.