A linkage is an assembly of rotating bars that is used to transmit or transform motion. They appear in all sorts of different mechanisms, including suspension systems, windshield wipers, and airplane doors... In this video we explore what linkages are, how they work, and how a linkage in the cargo door of the McDonnell Douglas DC-10 aircraft was responsible for the crash of Turkish Airlines Flight 981. **---** **Attribution:** _3d Models_ "Dc10" by manilov.ap (modified), https://skfb.ly/YRnB, Licensed under CC BY 4.0: http://creativecommons.org/licenses/by/4.0/ "Forest landscape" by Lassi Kaukonen, https://skfb.ly/oVAtE, Licensed under CC BY 4.0: http://creativecommons.org/licenses/by/4.0/ _Terrain and Imagery Data_ Copernicus Global Digital Elevation Model (30 m). European Space Agency (2024). Distributed by OpenTopography. https://doi.org/10.5069/G9028PQB. Accessed 2026-07-29. © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved. Aerial imagery: Source: IGN – BD ORTHO. Licensed under Licence Ouverte / Open Licence 2.0 (Etalab): https://www.etalab.gouv.fr/licence-ouverte-open-licence/ Satellite imagery: Contains modified Copernicus Sentinel data 2026.