Southwest Airlines Structural Failure Points to Flaws In Commercial Aviation System

by James T. Crouse on April 4, 2011

in Commercial Air Travel

The key language in the flurry of posts surrounding the Southwest Airlines 737-300 fuselage fatigue on Saturday is what Mike Van de Ven, Southwest’s chief operating officer, said in a statement: “Prior to the event regarding Flight 812, we were in compliance with the FAA-mandated and Boeing-recommended structural inspection requirements for that aircraft. What we saw with Flight 812 was a new and unknown issue.”

First, it is terrifying to think that neither the FAA regulations nor the Boeing maintenance and inspection requirements were sufficient to describe procedures by which this flaw could have been detected. Fatigue cracks and aircraft structural flaws have been around for years—since we left wood and fabric behind in aircraft design and manufacture. The reasons for these metallurgical phenomena are well known, especially in the age of aircraft pressurization. It was not so long ago—1988—that Aloha Airlines Flight 243, Boeing 737-200, lost a major portion of its roof and killed a flight attendant. Months later, in 1989, United Boeing flight 811 a Boeing 747 lost a 12 x 25 section of its fuselage over the Pacific, killing nine and injuring twenty-three.These three aircraft have a vital factor in common (besides being made by Boeing), age—they were 15 years old (Southwest) 19 years old (Aloha) and 19 years old (United). Unlike automobiles, age on aircraft is not necessarily a bad thing—it proves design concepts, maintenance and inspection procedures, etc. But it is astonishing that after the high-profile fuselage separations which occurred in recent memory, someone at the FAA or Boeing did not think that fatigue issues in aging commercial passenger transport aircraft skins were important enough to address by regulation or inspection procedure, respectively.

One organization has suggested that it is the fault of self-regulation—allowing the airlines to self-police. They might have a point—ever notice those stories of how the FAA eventually find maintenance errors after several years and hundreds episodes?

But that’s if procedures exist and the airlines aren’t following them. If, on the other hand, procedures for inspecting commercial transport aircraft do not exist which would allow inspectors to find these sorts of faults, they need to be developed before these separations occur. On-aircraft inspection equipment exists to make this sort of inspection relatively simple and sure. Effective means to utilize that equipment need to be developed so that these aircraft can be inspected at regular intervals before more separations occur.

What happened with Southwest Flight 812 was not a “new and unknown” issue as Mr. Van de Ven states. He should know better.

Just two years ago, in July 2009 Southwest Airlines Flight 2294 – a Boeing 737-300- had a foot-long hole open in the top of the airliner at 30,000 feet, forcing an emergency landing in West Virginia. Also in 2009, the airline was fined $7.5 million by the FAA for almost 60,000 flights where airliners were used that had not undergone required inspections for fuselage cracks.

Fatigue cracking of aircraft skins has been known ever since metals skins were introduced. It should be well known by any airline—but certainly Southwest. To say it is unknown in light of aviation history is to claim ignorance, or worse, which will eventually result in the loss of an aircraft.

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