The Airport Operations Plan (AOP) is a concept that was defined by the SESAR Joint Undertaking, a working group of the European Commission that is responsible for optimising European airspace. In order to support airports and air traffic controllers in the implementation of such initiatives to improve European aviation, they can apply for subsidies. In 2017 Brussels Airport Company joined forces with 11 other airports and 2 air navigation services providers in order to coordinate and jointly elaborate an AOP in each airport.