Incident Overview
On Saturday, January 10, 2004, at approximately 17:00 UTC, a Cessna 310-Q registered as EC-CNC was involved in an incident at the Cuatro Vientos Airport. The aircraft, operated by Aerofan and powered by two Continental IO-470V0 engines, was conducting a general aviation instrument instruction flight with dual command.
Sequence of Events
The flight departed around 15:30 UTC with an instructor and two students on board. After completing basic maneuvers and simulated VOR-DME approaches, the crew returned to the airfield. While in the final third of the downwind leg for runway 28, the crew attempted to lower the landing gear but observed that the nose gear did not extend. They immediately notified the tower and abandoned the circuit.
Multiple attempts to deploy the gear using both normal and emergency procedures failed. The pilot declared an emergency and coordinated with air traffic control to avoid diverting other traffic due to approaching dusk. Given the poor condition of the unpaved runway, the pilot elected to land on the asphalt surface.
Landing and Damage
Approximately 40 meters before touchdown, the pilot cut the mixture, closed the fuel valve, and disconnected the electrical system and magnetos. The aircraft landed with full flaps deployed, touching down on the main gear while keeping the nose elevated until maximum deceleration was achieved. All three occupants exited the aircraft unharmed.
The aircraft sustained significant damage, including deformation and rupture of the nose gear doors, bending of the nose gear articulation bar, and breaks in the longerons and ribs within the nose gear housing. Additionally, both propeller blades were deformed, and the nose cone, antenna, and pitot tube were damaged.
Investigation Findings
Post-incident inspection revealed that a connecting bar between the initial gear mechanism and the housing was bent. Functional testing identified that one of the two bearings in the folding/unfolding articulation was locking at specific points due to poor lubrication. After greasing the bearing, the gear system functioned correctly both electrically and manually.
Review of maintenance requirements indicated that the Cessna 310-Q service manual did not mandate inspection or lubrication of these specific bearings at the time of the incident. Subsequently, on August 2, 2004, Cessna issued a temporary revision requiring lubrication of these bearings every 1,000 hours or three years.