AIN Blog: Linguistic Restraint

 - May 2, 2011, 12:31 PM

The Southwest Airlines 737-300 that lost some fuselage skin last month must surely have provided its occupants with some horribly tense minutes, but the airplane made it safely back to terra firma. 

The general media were all over the story because the incident proved to the millions of people who don’t know airplanes intimately that, by jove, those things are indeed up there only by the grace of God and this one burst. Burst it did, yes, but in many quarters, some of them informed and educated about things aeronautical, the incident was described as a “catastrophic loss of cabin pressure/decompression/structural failure.”

In fact, it was far from catastrophic, a term that should remain reserved for what have been genuinely catastrophic and utterly disastrous losses of cabin pressure/decompressions/structural failures. Some examples:

• The original de Havilland Comet, in 1952 the world’s first jetliner to enter service. In 1954, fatigue from pressurization loads fractured the structure around square cutouts in the pressure vessel for windows or antennas and brought down two BOAC airplanes on January 10 and April 8, killing all aboard in both cases.

• March 3, 1974. A THY Turkish Airlines DC-10 came down in the forest of Ermenonville near Paris after its rear baggage door let go, causing such a massive pressure differential between the passenger cabin and underfloor baggage areas that the floor collapsed, in turn severing the flight controls. The airplane dived rapidly and uncontrollably back to earth not long after takeoff from Paris Charles de Gaulle Airport, killing all 346 aboard.

• Aug. 12, 1985. The Japan Air Lines 747SR whose improperly repaired aft pressure bulkhead came apart, sending enough air pressure into the tailcone to damage the vertical stabilizer and sever the flight-control hydraulics. The airplane flew around for 32 minutes, unleashed and aimless, until it hit two mountain ridges, clipping the first before hitting the second. The crew of 15 and all but four of the 509 passengers aboard perished.

• April 28, 1988. The Aloha Airlines 737 that lost its upper fuselage from forward of the wing to the front of the cabin, providing all of its 95 occupants with an infinitely more terrifying ride than the recent Southwest incident did. The airplane landed safely but not before one flight attendant was lost overboard in flight, the sole fatality. The airplane had logged more than 89,000 cycles. As with Southwest but on a much higher terror scale, cool piloting saved the day.

• Oct. 25, 1999. The Payne Stewart Learjet “ghost plane” accident. Pressurization failed, as did the flow of emergency oxygen, and all aboard succumbed to hypoxia. The aircraft flew northwest from Florida on autopilot until, its fuel supply exhausted, it eventually crashed in South Dakota.

Those were genuinely catastrophic accidents, in that they were sudden events that had disastrous (on a scale of one to 520 fatalities) and rapidly inevitable endings.

That was not the case with Southwest. Boeing’s structure proved itself failsafe in that the damage did not escalate; Boeing is not off the hook, however, with scrutiny coming to bear on the riveting technique its workers used during manufacture of that vintage of 737. Also, the Southwest pilots did what they were trained to do: they flew the airplane and got it back on the ground pronto. In other words, after a troubling failure, the system worked just the way it should this time–catastrophe averted.