The Federal Aviation Administration (FAA) is investigating cracks found on three of American's Boeing 767 aircraft. The cracks appeared near the pylon that joins the wing and engine, and investigators believe the engine could eventually have fallen off at least one of the planes.
The FAA has now asked American to examine dozens of planes in its fleet, and could order tests of 767s at other airlines based on what American finds. One of the pylons has reportedly been sent to a metallurgist, presumably to test for inherent weaknesses in the pylons themselves.
According to the AP, "The cracks came as a surprise to American and FAA officials because they happened well within the FAA’s required time frame for inspection of the pylons."
News of the cracks came just days after the parking brake failed on one of American's Boeing 777 aircraft. According to American, "The crew had completed the parking checklist and were preparing to exit the aircraft when the [plane began rolling] backwards. The Captain quickly returned to his seat and applied brakes. The first application reportedly had little resistance and did not slow the aircraft. His second application had no resistance with pedals fully depressed. The aircraft continued to roll aft into the middle of ramp exit 122 and almost into the terminal B ramp. Once momentum slowed, the aircraft rolled forward toward terminal D finally coming to a stop."
Understandably, passengers may be a bit unnerved by the timing and nature of these two problems, but we'll have to wait and see what the investigations turn up. If the pylon issue is endemic to Boeing aircraft, well, we have a problem.