Airbus A330 Safety Record

Delta Air Lines flight crew’s incorrect evaluation of the clearance between their airplane and the airplane directly ahead of them as they made a 90 degree right turn onto an adjacent taxiway.

The flight crew’s delayed landing after an in-flight engine fire, which reignited after both fire bottles were discharged and resulted in substantial damage to an engine pylon. Contributing to the delayed landing was likely the flight crew’s perception that the fire had been extinguished due to the disappearance of the primary engine fire warning indications after the fire detection loops were damaged and that a landing as soon as possible was not perceived to be necessary. Contributing to the duration of the fire was the contamination of an engine fire isolation system component which resulted in hydraulic fluid leaking into the designated engine fire zone after the engine was shutdown and the fire button was pressed.

The loss of control of the left-hand engine and the subsequent thermal damage to the left wing on landing during engine reverse operation was due to a blockage of the variable stator vane torque motor filter that resulted in the engine’s electronic engine control to improper schedule maximum fuel flow resulting in flames out the engine’s exhaust tailpipe that impinged the wing. Contributing to the event were: - The presence of water containing dissolved aluminum sulfate (alum) in the airplane fuel system that initiated a sudden blockage of the engine VSV TM SP filter. - The maintenance provider omitted to sump the fuel tanks during the 10-day period of inactivity of the airplane. - While the engine was in an internally stalled condition during the reverse and post-reverse thrust operation, the electronic engine control logic allowed the fuel metering unit to supply maximum fuel flow despite the throttle at idle speed.

A No. 1 engine fire caused by a fuel manifold supply line high cycle fatigue crack which led to a fuel leak that subsequently ignited on hot engine case surfaces. The fatigue crack originated and progressed due to elevated fuel manifold assembly vibration levels. Engine vibration testing identified a combustor tone that excites a natural (resonant) frequency of the fuel manifolds at specific engine speeds on Pratt & Whitney PW4000-94 and -100 inch fan series engines that feature a TALON II combustor.

Brief and temporary blockage of the pitot probes in cruise flight, most likely due to ice crystals aloft, leading to erroneous airspeed indications and airplane automation degradation as designed. Contributing to the incidents were design features of the Thales AA probes which left them more susceptible to high altitude ice crystal icing than other approved pitot probe designs.