History of Flight
On September 21, 2014, at about 1405 eastern daylight time, Delta Air Lines flight 295, a Boeing 747-451, N669US, experienced a loss of power followed by an in-flight undercowl fire in the No. 4 engine (Pratt & Whitney PW4056 turbofan) shortly after takeoff from Hartsfield-Jackson Atlanta International Airport (ATL), Atlanta, Georgia. The airplane was making a maximum power takeoff from runway 27 Right. The pilots reported normal engine operation during the takeoff roll until just after liftoff. At about 400 feet above ground level (AGL), the pilots heard a loud bang, the airplane yawed, and cockpit instruments indicated a loss of power in the No. 4 engine. The pilots performed the quick reference handbook (QRH) engine failure checklist and shut down the No. 4 engine. At about 1,300 feet AGL, the No. 4 engine fire warning activated. The pilots performed the QRH engine fire checklist and discharged the A fire bottle into the engine nacelle. When the fire warning did not extinguish after one minute, the pilots discharged the B fire bottle; the warning extinguished about 20 seconds later. The pilots dumped 280,000 pounds of fuel and returned to ATL for a three-engine landing on runway 27 Right without further incident. The airplane stopped on the runway; after the fire department determined the engine was safe, the airplane taxied back to the gate. The flight was a regularly scheduled international passenger flight under 14 CFR Part 121 from ATL to Narita International Airport, Tokyo, Japan.
Injuries to Persons
There were no reported injuries to the 4 pilots, 13 flight attendants, or 316 passengers.
Damage to Airplane
The airplane received minor thermal damage to the interior surfaces of the left and right core cowls. No other damage was sustained.
Other Damage
No other damage was reported.
Airplane Information
The airplane was a Boeing 747-451, serial number 24224, manufactured in 1990, with 103,501 hours since new. Maximum takeoff gross weight was 870,000 pounds; at the time of the incident, gross weight was 866,200 pounds. The No. 4 engine, serial number 727873, was manufactured in January 1990, had 56,240 hours and 7,080 cycles since new, and had been installed on the airplane on February 9, 2014, after an overhaul, with 2,738 hours and 320 cycles since installation.
Flight Recorders
The digital flight data recorder (DFDR) showed that at 14:03:28, all four engines' parameters increased from idle to maximum power by 14:03:42. Takeoff occurred around 14:04:29. At 14:04:44, the No. 4 engine's parameters were normal. At 14:04:46 (about 364 feet AGL), parameters dropped significantly, indicating loss of power. At 14:04:50, fuel flow reached zero. The fire warning activated at 14:05:51 (about 1,100 feet AGL) and continued until 14:09:05.
Fire
The No. 4 engine experienced an undercowl fire with soot and heat damage on the right side of the engine, particularly aft of the intermediate case. The fuel line was intact but showed thermal distress. The hydraulic pressure line B-nut at the pulsation damper was found to be loose, dripping fluid when the engine was removed.
Tests and Research
The No. 4 engine was disassembled and examined. One 5th stage compressor blade was fractured transversely through the blade neck due to high cycle fatigue originating at the aft concave side corner. The blade showed evidence of grit blasting on the neck, contrary to repair procedures. The overhaul facility, Turbine Overhaul Services (TOS) in Singapore, had deviated from the required grit blasting distance (2 inches instead of 4–6 inches).