What happened
On March 5, 2015, a Beechcraft E55, registration PT-LSS, was performing a local flight at the Teruel Ipanema Estância Aerodrome (SSIE) in Mato Grosso do Sul, Brazil. The aircraft was operated for private purposes with a pilot and one passenger on board.
During the landing roll, the aircraft's landing gear—consisting of two main legs and a nose gear—unexpectedly retracted. This caused the aircraft to drag along the runway, resulting in substantial damage to the airframe. Despite the impact, both occupants emerged from the aircraft uninjured.
The investigation
CENIPA investigators examined the mechanical and operational aspects of the occurrence. The investigation focused on the landing gear system, which is electrically operated with a manual emergency extension capability. Investigators found no evidence of mechanical failure or malfunction in the landing gear components, specifically noting that the down-locks were functioning correctly and could not have caused an inadvertent retraction.
The analysis centered on the pilot's actions during the landing roll. The investigation revealed that the pilot performed post-landing procedures without consulting the aircraft's checklist and out of the prescribed sequence. The cockpit layout features a high density of controls in close proximity, including the landing gear lever on the center console alongside various other switches for flaps, lights, and fuel pumps.
While the aircraft was equipped with a safety switch on the main shock strut designed to interrupt the gear command circuit when the strut is compressed (indicating the aircraft is on the ground), the manufacturer's manual explicitly warns that this device should not be relied upon to keep the gear extended while on the ground. The manual states that the landing gear lever must never be moved to the 'UP' position while the aircraft is on the ground.
Findings
- The pilot failed to use the aircraft checklist during the post-landing phase.
- The pilot performed post-landing procedures out of the correct sequence.
- The inadvertent command of the landing gear retraction lever during the landing roll was the primary factor in the gear retraction.
- The proximity of various controls on the center console increased the risk of accidental activation.
- The aircraft's safety switch on the main strut is not a reliable safeguard against manual gear retraction while on the ground.