Collision-risk restructuring of Zurich airspace temporarily limits arrival capacity

Swiss air traffic controllers are to impose temporary capacity reduction at Zurich airport, in order to implement a new airspace structure which has been based on collision-risk modelling. The redesigned airspace – intended to minimise infringements – will come into effect from 20 March. Swiss air navigation service Skyguide will reduce Zurich arrival capacity by 20% for four weeks, and also restrict general aviation activity in the vicinity of the airport. The redesign features changes such as a revision of terminal airspace zones. It covers not only Zurich but the military airspace around Dubendorf airfield, and also involves adjustments to gliding areas. Skyguide says the “far-reaching” change is the largest to the airport’s airspace in “several decades”, but adds that it is “committed to minimising the impact”. The redesign has been spurred by a number of airprox incidents at Zurich but, in particular, a serious occurrence in March 2011 when two Swiss Airbus A320s were cleared for take-off on intersecting runways within 46s of one another. As the jets accelerated, the crew of the A320 on runway 28 – having seen the other A320 converging from runway 16 – aborted the take-off at 135kt. The abort was initiated 550m before the runway intersection and just as the other aircraft was lifting off at 162kt. Swiss investigators stated that the situation involved a “high risk” of collision. The inquiry found that the airport’s complex operation on intersecting runways was subject to only “a small error tolerance” during periods of high-volume traffic.<br/>