Alitalia MD-82 Engine Failure Incident (I-DACU)

Incident Overview and Flight Details On 25 September 2003, an Alitalia McDonnell Douglas MD-82, registration I-DACU, was operating a scheduled passenger flight from Naples Capodichino (LIRN) to Milan Linate (LIML). The aircraft departed at 10:33 UTC. During the climb phase, while crossing flight level 160, the crew reported a loud noise from the rear of the aircraft, and the right engine instruments indicated zero. The aircraft was located over the vertical of Teano VOR at the time of the event. ## Emergency Response and Landing The flight crew applied the emergency procedure for “ENGINE FIRE SEVERE DAMAGE OR SEPARATION.” After completing the procedure and isolating the failed engine, the crew declared an emergency and requested to return to the departure airport. At 10:50 UTC, the emergency declaration was cancelled, and the aircraft landed at 10:55 UTC without further issues. There were no injuries or damage to the aircraft or passengers. ## Aircraft and Engine Information The aircraft, serial number 53055, was built in 1991 and had a valid airworthiness certificate. The right engine was a Pratt & Whitney JT8D-217C, serial number 718517, installed on 20 June 2002. At the time of the incident, the engine had 27,025 hours and 26,048 cycles since new, and 2,248 hours and 2,526 cycles since the last overhaul. ## Investigation Findings The investigation was conducted on a documentary basis because the event was reported by a passenger nearly two years after the incident, which limited the availability of radar data and communications. Maintenance records showed that the engine had been serviced by certified organizations according to approved schedules. A significant prior event was foreign object damage (FOD) to two fan blades on 19 September 2003, but a borescope inspection on 21 September 2003 found no further internal damage, and the engine was returned to service. ## Engine Damage Analysis Upon disassembly, investigators found no significant damage to the compressor or the first and second stages of the low-pressure turbine (LPT). However, all rotor blades on the third and fourth LPT stages were broken at the root, and the third and fourth LPT stator clusters were severely damaged. The LPT casing was perforated at the third-stage LPT plane of rotation. Fractography of the remaining blade fragments showed typical brittle fracture morphology without evidence of progressive fatigue or FOD. The possibility of high-cycle fatigue (HCF) with evidence erased during the failure was noted. ## Historical Context and Corrective Actions The incident was part of a known pattern of third and fourth LPT rotor blade failures on JT8D-217 and -219 engines. Worldwide, approximately 200 similar cases were reported between 1991 and 2003. Alitalia recorded 14 such cases in its fleet of 178 engines during the same period. The manufacturer had issued several service bulletins to address shroud wear and blade fatigue, including SB 6090, SB 6149, and SB 6402. Despite these modifications, HCF failures continued, and the manufacturer introduced shroud wear limits and periodic inspections for older engine series.