Friday, August 22, 2008

Crash of Spanair MD-82 Could Have Been Prevented

One hundred fifty-three people were killed when a fully-loaded Spanair MD-82 crashed on takeoff from the Madrid airport on August 20, 2008. Witnesses describe an explosion in the left engine and the aircraft falling to the runway, veering off and then exploding into an inferno.

About one hour before the crash, the crew was reported to have aborted a takeoff because of a high temperature warning, known as an overtemp, from the left engine. Troubleshooting took place and the aircraft was again dispatched for a three-hour flight to the Canary Islands. The aircraft was full of fuel and the outside temperature was a warm 86 degrees Fahrenheit.

It is inexplicable and horrendous that an aircraft such as this was cleared for service without an engine change when they couldn’t possibly have known what damage resulted from the overtemp. This situation in a jet engine is a serious matter requiring extensive investigation, not merely an hour’s worth of troubleshooting. It does not happen without good, and usually serious, cause including imminent failure of hot section components, failure of compressor and fan assemblies or likely turbine disintegration.

Jet engines nearly always telegraph their imminent failure and this one surely did. It was ignored. The Pratt and Whitney JT8D engine has had a long and satisfactory service history starting with the Boeing 727, 737, DC-9 and all the MD-80's. While generally reliable, it has exploded all too frequently and is the subject of numerous service bulletins and airworthiness directives by the Federal Aviation Administration as well as aviation safety agencies in other countries. Some have exploded so violently that the containment rings that are designed to prevent penetration of debris into other critical aircraft components have proved to be insufficient.

When the MD-82 was built and certified, it was supposed to be able to safely fly with one engine if the other failed after reaching V1 (the speed at which it becomes safe to continue the takeoff in spite of the failure of an engine). However, the claim was substantiated by test pilots who know the engine will be simulated to fail, and not by flight crews who are totally surprised by the event on a hot day while fully loaded.

It is not surprising that the airplane didn't fly because expecting humans to perform to perfection is unreasonable, and the temperature and weight were likely well beyond the test parameters. At the controls were Spanair test pilots who were also victims of a cascade of events that came together to create this tragedy.

At this stage of aviation history, there is no reason for this disaster and both the horror and pain it has caused to so many families. Airline travel can and ought to be 100 percent safe if people do their jobs. This was an unnecessary accident.

Arthur Alan Wolk
August 22, 2008