Lateral Error on Airways

Extract

A. White's study of navigational accuracy near Strumble is artificial and draws some wrong conclusions. He seems to assume that it is a crime to be outside the airway. But this airway is isolated, with no mountains near cruising altitude, and no one infringed a neighbouring airway. In a terminal area I am sure accuracy is much higher, because it needs to be. Airway widths vary from one country to another and are unimportant and the boundaries are not evident to pilots, who try to stay not within the arbitrary boundaries but not too far from the centre line. The area just outside the official airway is just as safe and good as the airway, and indeed safer than the centre line where traffic density is highest and only an altitude mistake by controller or pilot is needed to promote a collision—natural dispersion is still safer than extreme accuracy. Crews generally fly only as accurately as necessary, reserving their energy for the most important tasks: the study of Strumble shows adequate accuracy. Incidentally routes and airways should follow the curved path of aircraft instead of the right-angled bends, for instance the standard inbound route to Gatwick: Lydd-Cliff-Mayfield.