thumb|350px|Schematic descent profile of a conventional approach (red) and a continuous descent approach (green). '''Continuous descent approach''' (CDA), also known as '''optimized profile descent''' (OPD), is a method by which aircraft approach airports prior to landing.<ref name=":0">{{Cite web |title=Continuous Descent {{!}} SKYbrary Aviation Safety |url=https://skybrary.aero/articles/continuous-descent |access-date=2025-09-29 |website=skybrary.aero}}</ref> CDAs avoid long segments of flight at a level altitude by allowing aircraft to descend continuously at a constant angle. It is designed to reduce fuel consumption and noise pollution compared to other conventional descents.<ref>{{Cite web |date=2021 |title=CAP 2302 - A Low Noise Arrival Metric |url=https://www.caa.co.uk/publication/download/19348 }}</ref><ref>{{Cite web |date=2020-11-06 |title=Continuous climb and descent operations (CCO / CDO) {{!}} EUROCONTROL |url=https://www.eurocontrol.int/concept/continuous-climb-and-descent-operations |access-date=2025-09-29 |website=www.eurocontrol.int |language=en}}</ref>
A continuous descent approach starts from the top of descent, i.e., at cruise altitude, and allows the aircraft to fly its optimal vertical profile down to runway threshold. Some airports apply constraints to this individual optimal profile.<ref name=":0" />
==United Kingdom== CDAs were first used at London airports, including Heathrow<ref name="Heathrow2004">{{Cite journal |author=BAA Heathrow |date=2004–2005 |title=Flight Evaluation Report 2004/05 |url=http://www.heathrowairport.com/assets//B2CPortal/Static%20Files/New2005Booklet.pdf |url-status=dead |archive-url=https://web.archive.org/web/20051126064156/http://www.heathrowairport.com/assets//B2CPortal/Static%20Files/New2005Booklet.pdf |archive-date=2005-11-26 |accessdate=2 November 2007}}</ref> and Gatwick<ref>{{Cite journal |author=BAA Gatwick |title=Flight Evaluation Report 2006/07 |url=http://www.gatwickairport.com/assets//B2CPortal/Static%20Files/FEU%20Report%202006-07.pdf |url-status=dead |accessdate=26 January 2008 |archiveurl=https://web.archive.org/web/20080227080554/http://www.gatwickairport.com/assets//B2CPortal/Static%20Files/FEU%20Report%202006-07.pdf |archivedate=27 February 2008}}</ref> in the early 2000s.
==See also== *List of aviation, avionics, aerospace and aeronautical abbreviations *Index of aviation articles *QTOL *Nap-of-the-earth
==References== {{reflist}}
Category:Air traffic control