Southwest’s white-knuckle ride in focus as NTSB probes engine

Bloomberg

Passengers aboard a crippled Southwest Airlines Co. jetliner endured a tense, bumpy, 22-minute ride after an engine failed and hurled a hail of shrapnel that blew out a window, causing the death of a woman.
The plane banked hard to the left by 41 degrees moments after the engine shutdown and its smooth exterior tore loose, dramatically increasing wind drag, said National Transportation Safety Board Chairman (NTSB) Robert Sumwalt. That’s about twice the maximum bank that a traveler is likely to experience on a typical flight, he said in Philadelphia.
Pilots on Flight 1380 from New York to Dallas were able to level the aircraft quickly, but its damaged wing and engine cover created high vibrations for the rest of the flight, which ended with an emergency landing in Philadelphia. Jennifer Riordan, a passenger who had been seated near a window, was partly sucked out of the plane before passengers pulled her back in.
Philadelphia’s medical examiner found that she died of blunt impact trauma to her head, neck and torso, the Associated Press reported.
Investigators are studying every moment of the brief flight, along with the maintenance history of the engines that powered the 17-year-old Boeing Co. 737-700 aircraft. Early indications point to metal fatigue where a fan blade on the afflicted engine had snapped off.
“We are very concerned about this particular event,’’ Sumwalt said. “Engine failures like this should not occur obviously.’’ Southwest is stepping up engine inspections as it grapples with its first accident to result in a passenger’s death. Examinations of the fan blades on its CFM56-7B engines will be completed within 30 days, the Dallas-based company said. The discount airline operates the world’s largest fleet of 737 jetliners, relying on the turbofan to power most of its more than 700 planes.
The Federal Aviation Administration said late Wednesday that it would issue an airworthiness directive for the CFM engine within the next two weeks. The directive will require “an ultrasonic inspection of fan blades when they reach a certain number of takeoffs and landings. Any blades that fail the inspection will have to be replaced,” the FAA said. The directive finalises actions the agency proposed last August.
The NTSB probe hasn’t uncovered any systemic issue with Southwest aircraft or planes at other airlines that requires immediate action, Sumwalt said. The NTSB has the power to move quickly to raise alarms if such problems are found.
On that plane, also a 737-700, a fan blade on a jet engine snapped off and sent debris slamming into the fuselage, safety-board investigators determined. They found evidence of a crack “consistent” with metal fatigue in the titanium-alloy blade. The jet was forced to make an emergency landing in Pensacola, Florida, after the plane lost cabin pressure and passengers tweeted pictures of themselves with oxygen masks on.
Regulators recommended an ultrasonic inspection of fan blades in CFM56-7B turbofans, while CFM issued bulletins to its operators outlining testing that’s needed.
Inspections of about 690 engines are “well underway,” United Continental Holdings Inc. said. American Airlines Group Inc. already finished inspecting its 304 Boeing 737-800s with the same engine type, a spokesman said. Delta Air Lines Inc. said it “will take appropriate action as this ongoing investigation continues.”
Southwest completed inspections of its CFM56-7B engines earlier, and was partway through its own program to check the turbines on all of its 737-700s and -800s when the accident occurred, said spokeswoman Brandy King. The CFM56 series turbofan, one of the most widely used jet engines and the sole engine for Boeing’s 737 New Generation family, has amassed more than 350 million flight hours on 6,700 aircraft since entering the market in 1997.