What happened
On April 9, 2018, an Airwing AS Beechcraft King-Air B200, registration LN-NOA, was performing a commercial flight from Oslo Gardermoen to Stavanger Sola to transport medical equipment. During the approach to Stavanger, the crew transitioned to manual flying after the aircraft drifted off the localizer.
Upon touchdown, the aircraft's landing gear collapsed, causing the propellers to strike the runway surface. The aircraft slid approximately 277 meters along the runway, sustaining damage to the nose gear mechanism, bent propellers, and scrapes along the fuselage and flap trailing edges. There were no injuries to the two crew members on board.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the aircraft's electromechanical landing gear system and the crew's actions. While the captain suggested that an accidental upward movement of the gear lever—potentially influenced by low blood sugar—caused the collapse, the investigation found no mechanical failure in the gear's drive mechanism that could have caused the gear to retract spontaneously.
Technical analysis revealed that the 60A fuse for the motor had tripped, indicating that the gear was likely in transit (moving) while the aircraft was on the ground. The investigation also noted that the landing gear safety switch, which is designed to prevent retraction when the gear is weight-on-wheels, was functioning correctly. The NSIA concluded that the landing gear was likely in the process of being extended just as the aircraft hit the runway, causing the mechanism to jam and the motor to overload.
Findings
- The primary cause of the accident was that the landing gear was not fully extended and locked at the moment of touchdown.
- The crew's attention to standard checklists and procedures may have been compromised due to the high mental workload required for manual flying in low-visibility conditions (IMC).
- The captain's reported low blood sugar level may have contributed to a lapse in situational awareness or procedural execution.
Safety action
- The NSIA noted that while permanent runway camera surveillance is not a regulatory requirement in Norway, such systems could provide vital evidence for future accident investigations.
- The investigation highlighted the importance of maintaining physiological well-being (such as nutrition) to ensure optimal decision-making during high-workload phases of flight.