Due to its crucial structural role, the wingbox is subjected to considerable analysis and scrutiny in order to be certain of its capabilities, as well to achieve optimum performance. As such, various techniques to calculate and verify the stresses involved have been devised by aerospace engineers and employed by aircraft manufacturers. The use of increasingly capable calculations and tests has been directly credited with enabling the production of lighter and more efficient wings. Destructive testing of wing elements has been around since the earliest days of aviation, although the specific techniques employed have become increasingly sophisticated, particularly since the invention of the
strain gauge in 1938, which has been in widespread use within the aerospace industry since the
Second World War. Non-destructive testing is also performed not only during the initial certification process but often throughout an individual aircraft's life to safeguard against fatigue failure and inspect potential damage inflicted. Common techniques include visual inspection,
ultrasonic testing,
radiographic testing,
electromagnetic testing,
acoustic emissions, and
shearography. Sometimes, via such techniques, the need to replace an individual aircraft's wingbox is identified; although this is a quite intensive and costly procedure, leading to operators often choosing to end an aircraft's operating life instead, such replacements are occasionally performed. During Summer 2019, the
United States Air Force was compelled to ground over 100 of its
Lockheed Martin C-130 Hercules transport aircraft for inspection and remedial work upon discovering excessive wingbox cracking. Aircraft intended for lengthy service lives have often received replacement wingboxes as a part of life extension programmes. ==See also==