aircraft maintanance and metal fatigue

[Guest scott fletcher]

a very intresting article this one .

 

If you have ever unwound and bent a paper clip to and fro until it snapped, you understand the concept behind metal fatigue.

 

Railroad engineers in the late 19th century were the first to recognize the problem. As NASA's Brent Wellman wrote in 1997, "A large number of accidents involving train axles which SHOULD have easily handled the loads on them, led engineers to describe the parts as being 'tired,' or 'fatigued.'"

 

Metal fatigue entered the Jet Age with the tragic tale of the de Havilland Comet. The first commercial jetliner disintegrated in flight in 1954, killing all the passengers and crew. After a massive and expensive effort, investigators determined cracks formed near the Comet's windows causing the pressurized cabin to fail which lead to a catastrophic in-flight breakup.

 

http://www.pbs.org/newshour/rundown/2011/04/southwest-cracks-in-the-system.html