Editing Airframe (section)

== Safety ==

Airframe production has become an exacting process. Manufacturers operate under strict quality control and government regulations. Departures from established standards become objects of major concern.<ref>{{cite news |author= Florence Graves and Sara K. Goo |title= Boeing Parts and Rules Bent, Whistle-Blowers Say |newspaper= Washington Post |date= Apr 17, 2006 |url= https://www.washingtonpost.com/wp-dyn/content/article/2006/04/16/AR2006041600803.html |access-date= April 23, 2010}}</ref>

[[File:DH106 Comet 3 G-ANLO FAR 1954.jpg|right|thumb|DH106 Comet 3 G-ANLO demonstrating at the 1954 [[Farnborough Airshow]]]]

A landmark in aeronautical design, the world's first [[jet airliner]], the [[de Havilland Comet]], first flew in 1949. Early models suffered from catastrophic airframe [[metal fatigue]], causing a series of widely publicised accidents. The [[Royal Aircraft Establishment]] investigation at [[Farnborough Airport]] founded the science of aircraft crash reconstruction. After 3000 pressurisation cycles in a specially constructed pressure chamber, airframe failure was found to be due to stress concentration, a consequence of the square shaped windows. The windows had been engineered to be glued and riveted, but had been punch riveted only. Unlike drill riveting, the imperfect nature of the hole created by punch riveting may cause the start of fatigue cracks around the rivet.

The [[Lockheed L-188 Electra]] turboprop, first flown in 1957 became a costly lesson in controlling [[oscillation]] and planning around [[metal fatigue]]. Its 1959 crash of [[Braniff Flight 542]] showed the difficulties that the airframe industry and its [[airline]] customers can experience when adopting new [[technology]].

The incident bears comparison with the [[Airbus A300]] crash on takeoff of the [[American Airlines Flight 587]] in 2001, after its [[vertical stabilizer]] broke away from the [[fuselage]], called attention to operation, maintenance and design issues involving [[composite material]]s that are used in many recent airframes.<ref>{{cite web |author= Todd Curtis |title= Investigation of the Crash of American Airlines Flight 587 |work= AirSafe.com |date= 2002 |url= http://www.airsafe.com/events/aa587.htm }}</ref><ref>{{cite web |author= James H. Williams Jr. |title= Flight 587 |publisher= Massachusetts Institute of Technology |date= 2002 |url= http://web.mit.edu/jhwill/www/Flight587.html |author-link= James H. Williams, Jr }}</ref><ref>{{cite news |author= Sara Kehaulani Goo |title= NTSB Cites Pilot Error in 2001 N.Y. Crash |newspaper= Washington Post |date= Oct 27, 2004 |url= https://www.washingtonpost.com/wp-dyn/articles/A63850-2004Oct26.html |access-date=April 23, 2010}}</ref> The A300 had experienced other structural problems but none of this magnitude.