L2016-02 Landing gear failure during landing run at Oulu Airport on 3 October 2016

A Reims F406 Caravan II aircraft (OH-OTL), operated by the Finnish company Lapin Tilauslento Oy, departed for a routine cargo flight from Rovaniemi Airport to Oulu on 3 October 2016. The aircraft had a crew of two pilots and carried mail as cargo.

When the landing gear was retracted after take-off, the warning lights for the landing gear and hydraulic system remained on. The gear was then selected back down, and the three green lights indicating that the gear was down and locked illuminated normally. The crew continued the flight to Oulu in good weather with the gear extended. When approaching at Oulu, it was already dark.

When landing at Oulu, the aircraft touched down at the beginning of the runway. The landing run was normal at first. After the speed had decreased and the pilot-in-command started braking, the right main landing gear failed and the aircraft tilted to the right. The aircraft stopped quickly after the landing gear had collapsed, within a distance of about 80 m, but remained on the runway. The aircraft sustained significant damage in the area between the right propeller and the inner wing flap on the right-hand side. There were no injuries to persons.

Before the accident flight, the aircraft main landing gear had been subjected to maintenance, for which the gear had to be removed and reinstalled. When the right main landing gear was installed, its forward pivot pin had been secured incorrectly. As a result of this error the pivot pin moved out of its place, eventually causing the gear to collapse at landing.

The investigation revealed shortcomings in the main landing gear installation instructions, and the order of actions was found to be impractical in places. Therefore they did not support the correct performance of maintenance actions and related inspections. These factors have contributed to the accident besides human factor elements.

The Safety Investigation Authority, Finland recommends that the type certificate holder of Reims F406 aircraft review and update the maintenance instructions so that any deficiencies in main landing gear installation instructions are rectified. In addition, it is recommended that the type certificate holder of Cessna 404 aircraft, which has a similar type of landing gear, also review the corresponding instructions, including those for other similar aircraft types.

The recommendations are issued to improve safety, to prevent similar accidents in the future, and to minimise any damage resulting from such accidents.

Final report L2016-02 (pdf, 0.33 Mt)