in the 1980s Mike Bloodworth carried out work of some scholarship on the above subject. Mike’s work was treated with great respect, even admiration, from bodies such as GATCO, GAPAN and BALPA. Mike also received considerable support and feedback from pilots, airlines and manufacturers. The work was treated with some concern and suspicion by CAA and NATS, not least because they were concerned that it was not a procedure that all controllers could apply with equal understanding and skill.
Thirty five years later we are becoming used to the idea of working with aircraft trajectories through the availability of controller tools. Mike’s work anticipated that but was perhaps too soon for the technology that was to come. Click on the link below to read the paper.