Investigators examine engine wear in jet tragedy
Incident similar to one on a Southwest plane 2 years ago.
The investigation into a deadly engine failure on a Southwest jet is focusing on whether wear and tear caused a fan blade to snap off, triggering a catastrophic chain of events that killed a passenger and broke a string of eight years without a fatal accident involving a U.S. airliner.
From investigators’ initial findings, the accident appears remarkably similar to a failure on another Southwest plane two years ago — an event that led the engine manufacturer and regulators to push for ultrasonic inspections of fan blades on engines like the one that blew apart at 32,500 feet over Pennsylvania on Tuesday.
When investigators from the National Transportation Safety Board examined the broken engine in Philadelphia just hours after it made an emergency landing, they immediately saw that one of the left engine’s 24 fan blades was missing.
“This fan blade was broken right at the hub, and our preliminary examination of this was there is evidence of metal fatigue where the blade separated,” said NTSB chairman Robert Sumwalt.
Metal fatigue is a weakening of metal from repeated use and involves microscopic cracks. It can occur in fan blades, the aluminum skin on most planes, or other metal parts.
Investigators will focus on whether the fan blade broke off at cruising speed — around 500 mph — and started an “uncontained” engine failure that sent debris flying like shrapnel into the plane, where it broke a window.
A woman sitting near the window was sucked partially out of the plane before other passengers managed to pull her back in.
A registered nurse and emergency medical technician on board jumped in to try to save the gravely injured woman. But Jennifer Riordan, a Wells Fargo bank executive and mother of two from Albuquerque, New Mexico, died later. Seven other victims suffered minor injuries.
The pilots of the twin-engine Boeing 737 bound from New York to Dallas with 149 people aboard made an abrupt turn toward Philadelphia and began a rapid descent after the engine blew. Oxygen masks dropped from the ceiling, and passengers prayed and braced for impact.
“It sounded like the plane was coming apart, and I think we pretty quickly figured out that something happened with the engine,” retired nurse Peggy Phillips told WFAA-TV in Dallas.
She said they started losing altitude and the masks came down, and “basically I think all of us thought this might be it.”
Then she heard commotion a few rows behind her.
“It was a lot of chaos back there — a lot of really upset people and a lot of noise, and a big rush of air, a big whoosh of air,” Phillips said.