What happened
On March 20, 1999, an Iberia MD-87, registration EC-GRL, was operating a scheduled flight from Barcelona to Geneva with 101 passengers and 6 crew members. During the initial gear retraction after takeoff, the crew noted that the nose wheel indicator light remained illuminated longer than usual before eventually turning off.
During the approach to runway 05 at Geneva, the crew observed that the nose gear had failed to extend, accompanied by an audible cockpit alarm. The pilots immediately executed a go-around and notified air traffic control. Following a visual inspection by ground controllers, which confirmed the nose gear doors were partially open and the gear remained retracted, the crew entered a holding pattern to consult with maintenance personnel in Madrid.
To mitigate the risks of a gear-up landing, the captain requested that the runway be covered with a foam carpet. The aircraft performed a controlled landing, touching down on its main gear and maintaining a nose-high attitude until it reached the foam section. The forward lower fuselage made contact with the runway, and the aircraft came to a stop approximately 400 meters later. All 101 passengers and 6 crew members evacuated via emergency slides without injury.
The investigation
Investigators examined the nose gear assembly and the failed component, known as a deflector. Upon lifting the nose of the aircraft with specialized equipment, the crew was able to manually extend the gear. The investigation revealed that the deflector had suffered a double fracture.
Metallurgical analysis performed by a federal laboratory determined that the primary failure was caused by severe corrosion. The analysis found that the right side of the deflector had broken away from its mounting, causing it to shift out of its guide rail during the gear retraction process. This misalignment created a mechanical blockage that prevented the nose gear from extending via hydraulic or gravity-based emergency methods.
Findings
- The primary cause of the incident was a deliberate landing with the nose gear retracted due to an irreversible blockage.
- The blockage was caused by a fractured deflector that moved into the path of the retraction mechanism.
- The fracture originated from significant corrosion on the aluminum structure, which was exacerbated by the presence of chlorides.
- A lack of protective coating on the connection surfaces allowed corrosive elements to penetrate the material, leading to intergranular corrosion.
- The secondary fracture in the component occurred due to structural overload following the initial corrosive failure.
- The defect was nearly impossible to detect during standard ground inspections because the component appeared normal from the outside.