Editing McDonnell Douglas DC-10 (section)

===Cargo-door problem===
{{main|American Airlines Flight 96|Turkish Airlines Flight 981}}
The DC-10 has cargo doors that open outward; this allows the cargo area to be completely filled, as the doors do not occupy otherwise usable interior space when open. To overcome the outward force from [[pressurization]] of the fuselage at high altitudes, outward-opening doors must use heavy locking mechanisms. In the event of a door lock malfunction, there is greater potential for [[explosive decompression]].<ref name=waddington_p85-6>{{harvnb|Waddington|2000|pp=85–86}}</ref>

On June 12, 1972, [[American Airlines Flight 96]] lost its [[aft]] cargo door above [[Windsor, Ontario]]. Before takeoff, the door appeared secure, but the internal locking mechanism was not fully engaged. When the aircraft reached approximately {{convert|11750|ft|m}} in altitude, the door blew out, and the resulting explosive decompression collapsed the cabin floor.<ref name=aci>"Behind Closed Doors". ''Air Crash Investigation, Mayday (TV series)''. [[National Geographic Channel]], Season 5, Number 2.</ref> Many control cables to the [[empennage]] were cut, leaving the pilots with very limited control of the aircraft.<ref name=fielder_birsch_p94>{{harvnb|Fielder|Birsch|1992|p=94}}</ref><ref>[http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR73-02.pdf "NTSB-AAR-73-02 Report, Aircraft Accident Report: American Airlines, Inc. McDonnell Douglas DC-10-10, N103AA. Near Windsor, Ontario, Canada. June 12, 1972"] {{Webarchive|url=https://web.archive.org/web/20171025060546/http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR73-02.pdf |date=October 25, 2017}}. ''[[National Transportation Safety Board]]'', Washington, DC, February 28, 1973.</ref> Despite this, the crew performed a safe emergency landing.{{sfn|Waddington|2000|p=67}} U.S. [[National Transportation Safety Board]] (NTSB) investigators found the cargo-door design to be dangerously flawed, as the door could be closed without the locking mechanism fully engaged, and this condition was not apparent from visual inspection of the door nor from the cargo-door indicator in the cockpit. The NTSB recommended modifications to make it readily apparent to baggage handlers when the door was not secured and also recommended adding vents to the cabin floor so that the pressure difference between the cabin and cargo bay during decompression could quickly equalize without causing further damage.<ref name=aci /><ref name="fielder 3">{{harvnb|Fielder|Birsch|1992|p=3}}</ref> Although many carriers voluntarily modified the cargo doors, no [[airworthiness directive]] was issued, due to a [[gentlemen's agreement]] between the head of the FAA, [[John H. Shaffer]], and the head of McDonnell Douglas's aircraft division, Jackson McGowen.<ref>{{Cite news |last=Witkin |first=Richard |date=1974-03-27 |title=Change on DC-10 Called Optional |language=en-US |work=[[The New York Times]] |url=https://www.nytimes.com/1974/03/27/archives/change-on-dc10-called-optional-faa-aide-says-an-accord-with-builder.html |access-date=2023-10-31 |issn=0362-4331 |archive-date=October 31, 2023 |archive-url=https://web.archive.org/web/20231031151352/https://www.nytimes.com/1974/03/27/archives/change-on-dc10-called-optional-faa-aide-says-an-accord-with-builder.html |url-status=live}}</ref> McDonnell Douglas made some modifications to the cargo door, but the basic design remained unchanged, and problems persisted.<ref name=aci /><ref name="fielder 45">{{harvnb|Fielder|Birsch|1992|pp=4–5}}</ref>

On March 3, 1974, in an accident circumstantially similar to American Airlines Flight 96, a cargo-door blowout caused [[Turkish Airlines Flight 981]] to crash near [[Ermenonville]], France,<ref name=aci /><ref name="fielder 5">{{harvnb|Fielder|Birsch|1992|p=5}}</ref> in the deadliest air crash in history at the time—346 passengers and crew died.<ref>[https://news.google.com/newspapers?nid=888&dat=19740304&id=p-tRAAAAIBAJ&sjid=RnMDAAAAIBAJ&pg=4842,3446994 "Plane crash in France kills 346"] {{Webarchive|url=https://web.archive.org/web/20191213002438/https://news.google.com/newspapers?nid=888&dat=19740304&id=p-tRAAAAIBAJ&sjid=RnMDAAAAIBAJ&pg=4842%2C3446994 |date=December 13, 2019}}. ''St. Petersburg Times'', March 4, 1974. Retrieved: May 30, 2012.</ref> The cargo door of Flight 981 had not been fully locked, though it appeared so to both cockpit crew and ground personnel. The Turkish aircraft had a seating configuration that exacerbated the effects of decompression, and as the cabin floor collapsed into the cargo bay, control cables were severed and the aircraft became uncontrollable.<ref name=aci /> Investigators found that the DC-10's relief vents were not large enough to equalize the pressure between the passenger and cargo compartments during explosive decompression.<ref name=TA_Flt_981>[http://www.aaib.gov.uk/sites/aaib/cms_resources/8-1976%20TC-JAV.pdf "Turkish Airlines DC-10, TC-JAV. Report on the accident in the Ermenonville Forest, France on March 3, 1974"] {{Webarchive|url=https://web.archive.org/web/20090316163103/http://www.aaib.gov.uk/sites/aaib/cms_resources/8-1976%20TC-JAV.pdf |date=March 16, 2009}}. ''UK Air Accidents Investigation Branch (AAIB)'', February 1976.</ref> Following this crash, a special subcommittee of the [[United States House of Representatives]] investigated the cargo-door issue and the certification by the [[Federal Aviation Administration]] (FAA) of the original design.<ref name=Endres_p55/> An airworthiness directive was issued, and all DC-10s underwent mandatory door modifications.<ref name=Endres_p55>{{harvnb|Endres|1998|p=55}}</ref> The DC-10 experienced no more major incidents related to its cargo door after FAA-approved changes were made.<ref name=aci />