Editing Air traffic control (section)

===Congestion===
Constrained control capacity and growing traffic lead to [[flight cancellation and delay]]s.<ref>{{Cite news |last=Harkoftaki |first=Matina |date=2 April 2025 |title=Air traffic congestion over Athens causes delays |url=https://www.ekathimerini.com/economy/1265935/air-traffic-congestion-over-athens-causes-delays/ |publisher=ekathimerini |access-date=13 May 2025 }}</ref><ref>{{Cite news |last=Davies |first=Phil |date=3 March 2025 |title=Air traffic control delays and congestion hit Norse Atlantic performance |url=https://travelweekly.co.uk/news/air-traffic-control-delays-and-congestion-hit-norse-atlantic-performance |publisher=Travel Weekly |access-date=13 May 2025 }}</ref>

* In America, delays caused by ATC grew by 69% between 2012 and 2017.<ref name="Economist15jun2019" />  ATC staffing issues were a major factor in congestion.<ref>{{Cite web|last=Gilbert|first=Trish|date=15 June 2016|title=Air traffic control staffing shortage must be addressed|url=https://thehill.com/blogs/congress-blog/technology/283328-air-traffic-control-staffing-shortage-must-be-addressed/|website=The Hill|access-date=12 August 2022}}</ref><!--ref name=Economist15jun2019-->
By then the market for air-traffic services was worth $14bn.<!--ref name=Economist15jun2019-->  More efficient ATC could save 5-10% of aviation fuel by avoiding [[holding pattern]]s and indirect [[Airway (aviation)|airway]]s.<ref name="Economist15jun2019" />

The military takes 80% of Chinese airspace, congesting the thin corridors open to airliners.<!--ref name=Economist15jun2019-->  The United Kingdom closes its military airspace only during [[British Armed Forces|military]] exercises.<ref name=Economist15jun2019/>