Purple Corridor
In United Kingdom aviation, a purple corridor is an area kept free from commercial or other aircraft to allow for the passage of royal or other VIP aircraft.
Separation distance
It includes a stipulation that no plane takes off or leaves within 20 minutes of a royal plane.[1]
It had a vertical clearance of 3,000 ft, and horizontal clearance of 20 miles in 1960.[2]
Incidents
On 25 October 1960, after a visit to Germany and Denmark, a Queen's Flight (32 Sqn) de Havilland Comet aircraft was 'buzzed' by two West German North American F-86 Sabre aircraft, at 30,000 ft, 20 miles north of Groningen Airport Eelde, near the German-Dutch border. The British pilot was Flight Lt Frank Stevens, who saw 'two aircraft with iron crosses' pass 50 feet above the Comet.[3] Three West German Air Force officers arrived at RAF Lyneham, on 26 October 1960, to discuss the incident.[4] RAF investigation staff arrived at RAF Wildenrath, for a meeting of the Second Allied Tactical Air Force at JHQ Rheindahlen in Mönchengladbach.[5] The Germans had been told that the Comet would fly in the Amber airway from Heligoland to Groningen.[6]