What happened
On July 31, 2012, at 18:25 UTC, a BRM Land Africa Impala ultralight aircraft, registration CS-URY, departed from the José Ferrinho Aerodrome in Leiria, Portugal, for a recreational flight. The aircraft, carrying a pilot and one passenger, was flying at a low altitude along the coastline near Vieira de Lepland.
According to the pilot's account, the aircraft entered a stall while flying at a slow speed, causing it to strike the water. This impact caused the nose gear to fracture and detach, while the main landing gear was partially torn away, remaining attached only by the hydraulic brake lines. Despite the damage, the pilot managed to maintain control and proceeded to perform an emergency landing back at the Leiria aerodrome, approximately 16km away.
Upon touchdown, the main landing gear detached completely from the airframe. The aircraft slid approximately 50 meters along the runway, resulting in significant damage to the lower fuselage, the tail cone, and the propeller blades, which made light contact with the pavement. Both occupants exited the aircraft uninjured.
The investigation
The GPIAAF examined the aircraft's structural components and the flight history. The investigation noted that the pilot had 100 total flight hours, with 41 hours in this specific aircraft. The aircraft was operating near its maximum takeoff weight of 450kg.
Investigators analyzed the fracture patterns on the landing gear. The damage to the nose gear occurred at the weld point of the main mast, a known structural weak point. The main gear failure involved the shearing of bolts and clamps. Notably, the investigators found that the mechanical forces required to cause such specific fractures—acting in a longitudinal, front-to-rear direction—were inconsistent with a typical wave impact on the sea, which would generally involve more widespread damage to the fuselage. Furthermore, the damage to the propeller tips suggested an impact with a solid or dense object rather than water.
Findings
- The investigation could not confirm the pilot's claim that a stall led to the sea impact, as the aircraft's characteristics and weight should have allowed for recovery without a significant loss of altitude.
- The physical evidence of the landing gear fractures indicated high-magnitude longitudinal shear forces, which did not align with the expected dynamics of a water impact.
- The true cause of the incident remains undetermined due to a lack of corroborating witnesses and inconsistencies between the reported sequence of events and the physical damage found on the airframe.
Safety action
While no specific safety recommendations could be formulated due to the undetermined cause, the GPIAAF emphasized the necessity of strict adherence to existing operational procedures and legal regulations to prevent deliberate disregard for safety standards.