Aircraft Survivability: Transport Aircraft Safety and Survivability, Spring 2005

On December 6, 1995, Pakistan International Airlines PIA flight 722, a Boeing 747-240 Combi airplane, experienced an uncontained failure in the Low-Pressure Turbine LPT area of the No. 2 engine shortly after takeoff from John F. Kennedy International Airport JFK, New York. The flight crew reported that as the airplane was climbing through 1,000 feet, they heard a loud thud and grinding noise and that the airplane then yawed to the left. The flight engineer reported that immediately after he heard the thud, he noted that the No. 2 engine oil-pressure and oil-quantity gauges both indicated zero. The flight crew continued the climb and later shut down the No. 2 engine. The airplane returned to JFK and landed without further incident. None of the 240 passengers and 15 crew members on board were injured. The airplane was operating on an Instrument Flight Rules IFR flight plan under the provisions of Title 14, Code of Federal Regulations CFR, Part 129, as a regularly scheduled international passenger and cargo flight from JFK to Charles de Gaulle Airport, Paris, France. The examination of the No. 2 engine revealed that most of the LPT module was missing. The airplane had punctures to its left-wing leading edge slats and to a landing-gear door. The No. 1 engine also had hard-body impact damage to 18 of the 38 fan blades, and the fan cowl had impact damage from the debris ejected from the No. 2 engine. The Survivability Division of Naval Air Warfare Center, Weapons Division NAWCWD has been working with the Federal Aviation Administration FAA under the Aircraft Catastrophic Failure Prevention Program ACFPP to transfer vulnerability-assessment computational models to conduct commercial safety analysis to assess aircraft hazards resulting from uncontained engine failures.