Wednesday, April 18, 2018

Southwest Engine Failure Kills Passenger

A Southwest Airlines flight from New York's LaGuardia airport to Dallas suffered a catastrophic engine failure yesterday that left one woman dead. The fatality was the first US airline death in nine years.

Southwest 1380 was a Boeing 737-700 twin-engine airliner operated by the Dallas-based, low fare airline. The flight is typically scheduled to take just under four hours. The aircraft left the gate at LaGuardia at 10:27 a.m., three minutes early, and took off 16 minutes later.

As the airplane climbed to its planned cruising altitude of 38,000 feet, it suffered what appears to be an uncontained failure of the left engine. Radar data from shows that the plane only attained an altitude of about 32,000 feet before it started its descent. By this point, the plane was northwest of Philadelphia and about 20 minutes into the flight.

Generally, when pilots say they “lost an engine” they mean they lost power on the engine. In this case, it looks as though the Southwest crew lost large pieces of their engine. Pictures of the engine show the cowling at the front the engine nacelle peeled back or missing with much of engine's interior exposed.

On the portion of the air-traffic audio that has been released, a Southwest pilot tells the controller, “We have a part of the aircraft missing, so we're going to need to slow down a bit.” This indicates that the crew suspected structural damage after the engine explosion and didn't want to stress the airplane with high speed flight.

Jet engines contain a number of fans and turbines that spin at a high rate inside the engine cowling. In the case of Southwest 1380, it appears that finely-machined guts of the jet engine came apart violently, turning fan blades and other engine parts into shrapnel that peppered the fuselage. One of the pieces of engine hit a cabin window, causing a small hole and injuring a female passenger. A passenger reported that the crew was trying to plug the hole when the window completely shattered, pulling the female passenger partly outside the plane.

The woman's head and arms were outside the window and “passengers right next to her were holding onto her. And meanwhile, there was blood all over this man's hands. He was tending to her,” passenger Marty Martinez told CNN.

Airline cabins are pressurized by excess air from the engines. Contrary to popular belief, it takes a large hole to affect the cabin pressure. There are even holes built into the fuselage called outflow valves that allow excess cabin air to be dumped overboard to prevent overpressurization. In the case of window breaking, the engine air cannot keep up with the pressurization demands of the cabin and the airplane experiences a rapid decompression.

In a rapid decompression, the air inside the airplane rushes out quickly with a loud noise and the temperature quickly drops to below freezing. Wind and engine noise through the open window add to the chaos.

A rapid decompression is a maneuver that jet pilots routinely train for in the simulator. The pilots first don their oxygen masks since the thin air at high altitudes will render a person unconscious in a matter of seconds. The next step is to put the airplane into a steep dive to a safe lower altitude while making sure that the passenger oxygen masks have deployed in the cabin.

This steep, controlled dive may have given some passengers the incorrect idea that the airplane was descending out of control. FlightAware shows that the airplane descended from 30,000 to 10,000 feet, which is considered a safe altitude for an unpressurized aircraft, in about five minutes as it turned toward Philadelphia.

As the crew approached the airport, the pilot said, “Could you have the medical meet us there on the runway as well? We've got injured passengers.” She said that airplane was not on fire, but repeated, “Part of it's missing.”

“They said there's a hole and someone went out,” she added.

The plane landed uneventfully in Philadelphia about 20 minutes after the engine failure. One passenger was killed, but there were no other serious injuries reported among the 143 passengers and 5 crew members. Seven passengers reported minor injuries. The entire flight lasted only 40 minutes.

The only fatality was Jennifer Riordan, of Albuquerque, N.M., the New York Daily News reported. Riordan, vice president of community relations at Wells Fargo, is assumed to be the female passenger who was pulled partially out of the window, but this has not been confirmed.

US airline accidents have become exceedingly rare. The last fatal accident was in 2009 when the crash of Colgan 3407 left 49 passengers and crew dead as well as one person on the ground.

There have been similar accidents in US history where the endings were more tragic than Southwest 1380. In 1989, an engine exploded on a United Airlines DC-10, severing the flight controls and leaving the crew airborne with no way to control the airplane. Using the throttles for the remaining engines, the crew of United 232 was able to steer the plane to a crash landing in Sioux City, Iowa that left 111 of the 296 passengers and crew dead.

A year earlier in 1988, Aloha Airlines Flight 243 suffered a rapid decompression when a section of the cabin ceiling peeled off the aircraft at 23,000 feet. A flight attendant was sucked out of the 737-200 over the Pacific Ocean near Maui and her body was never recovered. The crew safely landed the airplane with no further deaths.

Southwest CEO Gary Kelly said that the engine had been inspected on April 15 and had flown about 40,000 cycles. It had been about 10,000 cycles since the engine's last overhaul.

“I'm not aware of any issues with the airplane or any issues with the engine involved,” Kelly said.

The cause of the catastrophic engine failure is not known. While extremely reliable, jet engines are not infallible. National Transportation Safety Board Chairman Robert Sumwalt said that board sees “about three or four [uncontained failures] a year, but not all involve US airlines. With airlines flying about 17 million hours annually, three or four failures is about as close to error-free as any transportation system can get.

In fact, aviation machines are so reliable that the weak link often lies with pilots and maintenance personnel. Southwest has been fined several times by the FAA for maintenance violations, but this is not unusual in itself. Many of the violations are technical and other airlines such as United and Delta have also been fined by the FAA.

In modern times, our machines are so reliable that we forget that flying five miles above in the earth in a pressurized metal tube that hurtles along 500 miles per hour is inherently dangerous. Things can and do go wrong, sometimes for no apparent reason and with no one to blame. It is at that time that the pilots truly earn their pay. The pilots of Southwest 1380 certainly earned theirs.

Originally published on The Resurgent

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