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Saturday, March 1, 2003

Safety News

In the Spotlight: Will the loss of the space shuttle Columbia add to public scrutiny of maintenance this year?

It became clear that maintenance will be in the spotlight after an Air Midwest Raytheon 1900D crashed on takeoff in Charlotte, North Carolina January 8, killing all 21 on board. Initial National Transportation Safety Board findings are that the elevators were mis-rigged. The flight may also have been tail-heavy.

The accident occurred nine flights after the elevators had been worked on at a Raytheon Aerospace facility under a long-term contract with Air Midwest. The NTSB is looking closely at the experience and training of the mechanic who worked on the elevators, the workload of the supervisor who oversaw that work, the adequacy of the supervisor's oversight, and the clarity of the rigging procedures.

The accident came on the heels of the safety board's report on the January 2000 crash of an Alaska Airlines MD-80 that cited major lapses in structural design and the maintenance and oversight essential to ensure those structures stay safe. Such lapses may lie at the root of the Columbia disaster and the deaths of its crew of seven.

NASA officials spent the weeks after the February 1 breakup playing "cause of the day"–it was a patch of foam from the external tank, no it was space debris, naw, it was foam AND ice–and trying to convince us that an investigation controlled and staffed by the space agency really is independent. But the basic problem is that the orbiter's left wing failed and appears to have overheated before it did so. That points to the robustness of its design and the maintenance and inspection procedures for keeping it safe.

The nature of spaceflight demanded that the shuttle architects and crews accept a design with possible single-point failures. But the safety margins were eroded over time by the chiseling of Washington budgeteers and the mismanagement of NASA bosses.

The central concern in the Columbia disaster is insulation–the stuff that may have broken off the big, orange external tank and the glass tiles lining the orbiter's belly that may have been damaged by the stuff from the tank.

The 25,000 or so tiles are critical to keeping the orbiter aerodynamically clean and minimizing heat build-up during re-entry. But they are installed by hand by technicians who in the past have been underpaid (according to one study) and harassed (according to another). A standard practice at the Kennedy Space Center in Florida where the orbiters are processed, for instance, has been to give technicians who err several "days on the beach"–days off without pay. Tile insulation has been faulty at times. But that management practice doesn’t help unmask and correct errors. It helps bury them.

If investigators look beyond Columbia's wing to examine what contributed to its failure, they may find the training and treatment of the shuttle maintenance workforce is as critical to safety as any design element, and that NASA and Washington may have been taught a key safety lesson: you get what you pay for.–Jim McKenna

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