What happened
On October 22, 2009, a De Havilland DHC-8-315, registration PH-DXB, operated by Denim Air for Air Nostrum, departed Barcelona Airport for San Sebastian. Shortly after takeoff, the crew noticed that the landing gear was not locked in the up position. After a visual confirmation from the flight attendant, the crew decided to return to Barcelona to attempt an alternate gear extension.
During the attempt to use the alternate system, the crew noticed the Landing Gear Alternate Release Door was open. They closed the door, which triggered loud, alarming noises, prompting them to reopen it. As the aircraft approached for landing, the cockpit indicators showed that while the main gear was down and locked, the nose gear remained unsafe. The crew declared an emergency and requested firefighting services.
Upon landing on runway 25R, the nose gear failed to support the aircraft, and the nose contacted the wet runway for approximately 12 seconds before the plane came to a stop. The incident resulted in minor damage to the aircraft's nose gear doors and fuselage. All 32 passengers and 3 crew members were evacuated, though the process was complicated by passengers attempting to bring hand baggage with them.
The investigation
The CIAIAC investigation focused on the technical functionality of the landing gear and the crew's performance. Investigators found that the aircraft's landing gear system was fully functional and had no mechanical defects or malfunctions. The investigation also examined the crew's use of Standard Operating Procedures (SOPs) and Crew Resource Management (CRM).
Technical analysis revealed that the crew exceeded the maximum speed limits for the gear-down configuration during the flight. Furthermore, the investigation scrutinized the cockpit environment, noting a lack of standardized checklists and a breakdown in communication between the pilot in command and the first officer. There were also observations regarding the pilot in command's performance, including potential subtle incapacitation and a failure to follow established flight deck protocols.