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On August 11, 2002, about 1920 eastern daylight time, a Boeing 747-256, Spanish registration EC-DNP, operated by Iberia Airlines as flight 6250, sustained a number 2 engine fire during the initial climb after takeoff and performed an emergency landing, with a subsequent evacuation, at the John F. Kennedy International Airport (JFK), Jamaica, New York. Four flight crewmembers, 12 flight attendants and 333 passengers were not injured. One flight attendant and 34 passengers sustained minor injuries and 2 passengers were seriously injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the flight destined for Madrid, Spain. The scheduled international passenger flight was conducted under 14 CFR Part 129.
The flight crew reported that shortly after takeoff, when the airplane was climbing between 1,300 and 1,500 feet, the number 2 engine fire warning light illuminated. The crew discharged both number 2 engine fire extinguisher bottles; however, the light remained illuminated. The flight crew declared an emergency, and performed an emergency landing on runway 13R. After landing, the flight crew initiated an emergency evacuation and intended to utilize the five evacuation slides on the airplane's right side.
During the evacuation, the slide/rafts at doors 4R and 5R did not operate as intended. The 4R slide/raft partially deployed and did not reach the ground. The 5R slide/raft partially deployed and reached the ground. Neither exit was used during the evacuation and all 369 passengers and 17 crewmembers evacuated through doors 1R, 2R, and 3R.
On site examination of the airplane revealed that the number 2 engine sustained an under cowl fire in the area of the accessory gearbox. The majority of the accessory gearbox case was consumed, while the underside of the engine exhibited signs of damage due to the fire. Examination of the engine fan, compressors, turbines and cowlings did not reveal evidence of any uncontained failures.
The majority of the rear accessory gearbox housing was missing, from the constant speed drive and main oil pump, to the outboard hydraulic pump. The front gearbox housing was missing from the alternator to the outboard hydraulic pump. The gearbox housing was missing in the area of the fuel pump/fuel control pad and all that remained were the attachment bolts.
The number 2 engine, the 4R and 5R slide/rafts, the cockpit voice recorder, and the flight data recorder were retained for further examination.
The accident occurred during the hours of daylight approximately 40 degrees, 38 minutes north latitude, and 73 degrees, 46 minutes west longitude.
INJURIES TO PERSONS
Ten passengers were transported to local medical facilities for treatment. One flight attendant was treated at the scene and released. A male passenger was admitted with respiratory failure after he became non-responsive to medical personnel in the triage area of the terminal. A female passenger sustained a fractured ankle.
The pilot-in-command was a check airman, who was originally seated in a jumpseat to observe the captain in training, seated in the left seat. Prior to the landing, the check airman switched seats with the co-pilot, who was seated in the right seat, and assumed control of the airplane. All pilots held a Spanish first class medical certificate, and an airline transport pilot certificate. The cockpit crew also included a flight engineer who occupied his normal position.
The accident airplane, serial number 22764, line number 554, was delivered directly to Iberia Airlines on February 26, 1982.
The airplane was maintained under an approved continuous airworthiness inspection program. The airplane had accumulated about 81,955 total hours, and approximately 593 hours since an "A-check" was performed, on June 29, 2002.
The airplane was equipped with four Pratt & Whitney JT9D-7Q, two-spool, high-bypass ratio, turbofan engines. Each engine consisted of a fan and four-stage low-pressure compressor (LPC), and an eleven-stage high-pressure compressor (HPC) driven by a four-stage low-pressure and two-stage high-pressure turbine, respectively.
The number 2 engine had accumulated 71,293 hours and 11,030 cycles, since new. The engine had accumulated 2,474 hours, and 326 cycles, since overhaul.
The weather reported at JFK, at 1851, included: winds 180 at 14 knots, visibility 10 statue miles, clear skies, temperature 77 degrees F, dew point 66 degrees F, altimeter 30.06 inches-hg.
The airplane was equipped with a Sundstrand digital flight data recorder (DFDR) and cockpit voice recorder (CVR). The DFDR was downloaded and captured the accident flight; however, the CVR exhibited sounds consistent with "bulk erasure" of the recording, and did not contain any useful information.
TESTS AND RESEARCH
The 4R and 5R slide/rafts were shipped to their manufacturer, Goodrich, in Phoenix, Arizona, where they were examined on September 17 and 18, 2002, under the NTSB Survival Factors Group.
The 4R slide/raft was manufactured in 1979, and most recently overhauled on October 5, 2001. The inflation bottle was also overhauled and hydrostatically tested during the slide/raft overhaul. Teardown examination of the 4R slide/raft revealed a fractured inflation hose in the area of the regulator end swivel wire groove. The fractured hose was submitted to the Safety Board's Materials Laboratory for examination. The Materials Laboratory Factual Report stated, "all features associated with the hose fracture were indicative of a recent overstress separation. No evidence of fatigue cracking or other type of preexisting defect was noted."
The investigation revealed Goodrich had issued service bulletin 25-241, on September 30, 1991, which recommended that operator's "replace any hoses with Manufacturing/Test dates prior to May 30, 1983...at the next scheduled maintenance action." The replacement hoses were modified to increase their side loading capabilities and had demonstrated an improved side load capability of more than a factor of two.
Iberia Airlines personnel reported that they chose not to implement the service bulletin because compliance was not mandatory, and their fleet had not experienced any problems with the hoses. Within 48 hours of the accident, Iberia tested all inflation hoses installed on their Boeing 747 fleet with the same or equivalent part number. All hoses tested meet the appropriate slide/raft maintenance manual requirements. Iberia airlines subsequently elected to comply with SB 25-241, which was performed on all applicable airplanes.
Teardown, and "flat fire" testing of the 5R slide/raft did not disclose any abnormalities, which would have precluded normal operation.
Number 2 Engine Teardown
The number 2 engine was shipped to Iberia's Madrid Maintenance Center, Madrid Spain, where it was examined on September 10, 2002, under the supervision of the NTSB Powerplants Group.
The examination revealed in part, that the High-Pressure Compressor (HPC) forward air seal stack had become disengaged from the hub. The key washer and retaining nut were found disengaged from the threads on the HPC rear shaft. There was evidence of light, grooved scoring on the HPC shaft in the area were the retaining nut was found loose on the shaft. The key washer anti-rotation slots in the HPC hub, exhibited signs of contact marks. Dimensional measurements of the HPC rear hub were within specification; however, the HPC hub snap diameter for the front air seal revealed it was worn out-of-limits.
The threads for the air seal stack retaining nut on the HPC shaft, were intact and did not exhibit any evidence of the nut being "pulled" off of the threads. There was a thread-like wear pattern in the HPC shaft that extended approximately 0.5 inches aft of the retaining nut threads. An area of thermal distress that was approximately 0.070 inches deep also accompanied this wear pattern.
The airplane was released on August 14, 2002, to a representative of Iberia Airlines.