Event Details

Title:Contained engine failure on a Douglas DC-9-32 on climbout from Dallas-Fort-Worth, December 12, 1995
Micro summary:A contained failure of the #2 engine occurred on this Douglas DC-9-32 on climb.
Event Time:1995-12-12 at 903 CST
File Name:1995-12-12-US.pdf
Publishing Agency:National Transportation Safety Board (NTSB)
Publishing Country:USA
Report number:FTW96IA066
Site of event:DFW Airport, TX
Departure:Dallas-Fort Worth International Airport, Dallas & Fort Worth, Texas, USA
Destination:Dallas-Fort Worth International Airport, Dallas & Fort Worth, Texas, USA
Airplane Type(s):Douglas DC-9-14
Flight Phase:Climb
Operator(s):Valujet Airlines
Type of flight:Revenue
Serious Injuries:0
Other Injuries:0
Executive Summary:

NTSB short summary:

fatigue failure of a first stage, high pressure, turbine blade.

NTSB synopsis:

After takeoff, Valujet Flight 224, a McDonnell Douglas DC-9-32, was climbing through about 5,000 feet, when a contained failure of the #2 engine occurred. The flight crew secured the engine and declared an emergency, and the airplane was vectored back to the airport, where a single engine landing was made without further incident. Examination and teardown of the Pratt & Whitney JT8D-9A engine revealed that a turbine blade (part number 823201) in the first stage high pressure turbine assembly had failed due to fatigue. The blade part number indicated that the leading edge of the blade had been reworked in accordance with Pratt & Whitney Service Bulletin 4345 to remove cracking. The engine had accumulated a total of 32,028 flight hours and 25,603 cycles, since last overhaul, it had accumulated 2,794 flight hours and 2,329 cycles.

NTSB factual narrative text:

On December 12, 1995, at 0903 central standard time, a Douglas DC-9-32, N930VV, registered and operated by Valujet Airlines Inc., as Flight 224 under the provisions of Title 14 CFR Part 121 on a regularly scheduled domestic flight, experienced a contained failure of the number 2 engine during initial takeoff climb from the Dallas/Ft. Worth International Airport. Visual meteorological conditions prevailed at the time of the incident and an IFR flight plan was in effect. The airplane was not damaged and there were no injuries to the 54 passengers and 5 crewmembers aboard the airplane. The flight's intended destination was Atlanta, Georgia.

According to the flight crew, the airplane was passing through 5,000 feet during the initial takeoff climb, when a loud bang was heard, followed by a moderate vibration. The captain retarded the number 2 engine to flight idle and the vibration continued. The flight crew secured the engine, declared an emergency, and the airplane returned to DFW where a landing was made on Runway 17L at 0930 without further incident.

Initial examination of the Pratt & Whitney JT8D-9A turbofan engine confirmed that the failure was contained and no evidence of internal or external fire was found. A preliminary boroscope inspection by contract maintenance personnel revealed that a first stage turbine blade failed. The airplane was released to the operator and the engine retained for further examination and teardown at a contract engine facility operated by Air New Zealand, in New Zealand.

Examination and teardown of the engine revealed that a blade (part number 823201) in the first stage high pressure turbine assembly (part number 587501, serial number 8B2545) failed due to leading edge fatigue. Since the last overhaul, the turbine disk had accumulated 2,794 hours and 2,329 cycles. Markings on the failed blade identified the vendor as Chromalloy Southwest. The teardown was observed by members of the Transport Accident Investigation Commission in Wellington, New Zealand. A written report was not rendered.

Total time on the airplane was 41,206 hours/33,846 cycles. The number two engine, serial number 667136 was manufactured on April 28, 1975, and had accumulated a total of 32,028 hours/25,603 cycles. Total time since last overhaul/installation was 2,794 hours/2,329 cycles.

Aircraft serial number 47723 (N930VV) was purchased by ValuJet from Turk Hava Yollari (THY), Turkish Airlines, on October 3, 1994, as part of a formal sales agreement for the purchase of nine DC-9-32 airplanes, five spare engines, and approximately 4,400 spare parts. A review of the maintenance documentation by the FAA inspector did not reveal any anomalies or uncorrected defects prior to the flight.

Aircraft serial number 47723 was the first of nine DC-9s to be flight delivered to ValuJet. Engine serial number 667136 was installed on the right (number 2) position as specified in the sales contract. The engine remained in that position until the time of this incident.
Learning Keywords:Operations - Bang, pop, crack, sizzle!
Operations - Maintenance
Systems - Engine - Contained Engine Failure


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