What happened
Shortly after departing Calgary International Airport on a flight to Amsterdam, the crew of a Boeing 767 operated by Martinair Holland N.V. heard a loud bang following takeoff. Flight instruments immediately indicated a loss of engine pressure ratio on the right engine. Upon reviewing emergency checklists, the crew identified that the right engine oil pressure had fallen below minimum limits, prompting an intentional shutdown of the engine.
To avoid the need for fuel dumping, the captain decided to perform an overweight landing at approximately 172,000 kg. The aircraft returned to Calgary and landed on runway 34. During the landing process, the aircraft's brakes became overheated. While the aircraft stopped on a taxiway, the heat caused three tire fuse plugs to melt, resulting in the deflation of three tires. Passengers were eventually deplaned via an air-stair and transported to the terminal by bus.
The investigation
Investigators examined flight data recorder (FDR) information, which showed that the right engine's exhaust gas temperature spiked and the oil pressure dropped to zero during the failure. Analysis of the right engine, a PW 4060, revealed that a blade in the 6th stage of the high-pressure compressor had fractured and separated at its root attachment. A second blade was also found to have a crack at the root.
Further laboratory analysis of the components determined that the cracks were the result of high-cycle fatigue, likely caused by stresses from the variable guide vanes, though the specific origin of these stresses remained unidentified. Additionally, the investigation noted that communications between the flight crew, air traffic control, and the airport emergency response team were hindered by congestion on the Calgary ground frequency.