What happened
On March 1, 1999, a Lockheed Electra L-188C, registration N-285F, was operating a scheduled cargo flight from Cologne, Germany, via Dublin, to Shannon Airport, Ireland. During the final approach to runway 24, the crew attempted to land using a 78% flap setting rather than the standard 100%. As the aircraft neared the runway, the crew realized the undercarriage had not been extended. Upon touchdown, the propeller blades struck the runway surface, prompting an immediate go-around.
During the subsequent climb, the number 3 engine suffered a catastrophic failure, disintegrating and separating from the airframe. Debris from the departing engine struck the number 4 engine and punctured the aircraft's fuselage. The loss of the engine caused a significant loss of electrical power and left the crew struggling with severe directional instability and insufficient climb performance. Despite the loss of power and the damaged airframe, the crew managed to stabilize the aircraft and perform a second landing on runway 24, where they evacuated without injuries.
The investigation
The AAIU investigation focused on why the landing gear was not deployed and why the engine failure occurred. Investigators examined the aircraft's maintenance records, which showed the plane had been recently serviced and had no deferred maintenance items. The investigation also reviewed the cockpit's warning systems, specifically the Ground Proximity Warning System (GPWS) and the landing gear warning horn.
Technical analysis revealed that the aircraft's configuration—specifically the use of 78% flaps—interacted with the warning systems in a way that contributed to the crew's oversight. The investigation also looked into the flight crew's performance, noting that while the landing checks were missed, the subsequent emergency handling was effective.