Airbus A330 Investigation Report

Airbus A330 Investigation
Investigating an engine oil system can be a daunting task. According to Anderson, considerable variations exist between failure progressions in this system (2009). These variations must be considered by all investigators, and the pursuit of non-typical causations should be considered. “The engine oil system has a relatively large number of indicated parameters by regulations (pressure, temperature, quantity, filter clogging)” (Anderson, 2009, p. 9.58). Although these indications are useful to both pilots and investigators, the lack of these fault indications does not necessarily mean the engine oil system is operating within its parameters. This investigation will progress through the standard processes and procedures,
The flight departed at 0145 eastern standard time, 10 minutes later while climbing through flight level 230 the crew reported a master warning system indication and requested a return to Miami International. In addition to the warning indication, they crew reported a message on the electronic centralized aircraft monitoring system indicating a number one engine turbine exhaust gas temperature (EGT) overheat. As an investigator this is the first clue as to what may be happening within the engine. According to Anderson “EGT is also used to monitor engine health and mechanical integrity. Excessive EGT is a key indicator of engine stall, of difficulty in engine starting, of a major bleed air leak, and of any other situation where the turbine is not extracting enough work from the air as it moves aft (such as severe engine damage)” (2009, p.
According the NTSB, damage was noted to the thrust reverser, left wing, and fuselage of the aircraft (2006). Further examination revealed the number one engine intermediate pressure turbine case rupture had left a gap between the intermediate and low pressure turbine cases and fractured the disk rear drive arm and all blades were missing from the blade slots. During this initial inspection it was also noticed that the high pressure and intermediate pressure turbine bearing chamber external vent tube had two holes burned through outboard of the intermediate pressure turbine connection. According to Anderson “Most turbine failures are the result of over-temperature which is usually caused by hot starts, compressor stalls, or excessive fuel” (2009, p. 8.60). As an investigator the next step will be to identify causal factors for a turbine failure and continue the