What happened
On October 19, 2002, a Boeing 737-300, registration G-IGOX, operating a charter flight from Naples Capodichino to London Stansted, experienced significant structural vibrations during its initial climb. At an altitude of 5,500 feet and an indicated airspeed of 250 knots, both the flight crew and passengers felt medium-intensity vibrations throughout the cabin.
While the crew found flight controls and systems to be operating normally, they decided to perform a precautionary landing at Milan Linate. During the flight, Milan Air Traffic Control informed the crew that debris, including rubber fragments and a panel presumably from the aircraft's landing gear, had been discovered on the runway in Naples. To verify the integrity of the landing gear, the crew performed a low-altitude flypast of the Milan Linate control tower. Although onboard indications suggested the gear was extended and functional, a subsequent inspection revealed substantial damage to the aircraft.
The investigation
The ANSV investigation focused on the source of the vibrations and the debris left on the Naples runway. Post-flight inspections of G-IGT0X revealed that the outer tire of the right main landing gear had burst. This failure caused a landing gear bay panel to detach, which subsequently struck the aircraft's structure, creating a 40x20 cm hole at the wing-to-fuselage junction and causing impact marks on the right flap.
Investigators examined the damaged tires and found that both the failed tire and another tire on the same gear had been recently retreaded. The investigation determined that the limits applied during the retreading process were inadequate for this specific tire type, originally manufactured by Bridgestone. As a result, the manufacturer, Dunlop, implemented new restrictions limiting retreaded tires to a maximum of three reguilds.
Findings
- The burst of the outer right main landing gear tire during the takeoff roll was the primary cause of the event.
- The tire failure led to the detachment of a landing gear bay panel.
- The detached panel and tire fragments struck the aircraft, causing a hole in the wing-fuselage junction and damage to the right flap, which generated the vibrations felt by the crew and passengers.
- The investigation identified that the procedures for tire retreading were insufficient for the specific tire model involved.