Concorde preferential treament?
Yes of course it does, but not necessarily at Heathrow. There are basically two westbound oceanic tracks for concorde, called in short, Sierra Mike and Sierra Oscar; they are leftover from an initial and more comprehensive set of routes when it was thought that a lot of airlines would purchase them. SM is the preferred track with SO a little less economical. For the last quarter century the rules in the ATC manual at the London Area Control Centre have been written so that the BA flight will always be given the most advantageous track whenever the French flight is operating about the same time. This problem no longer occurs since the new timetable came into force. Over 25 years that must have saved a fair bit of fuel. Just as an afterthought I should mention that it made the mental arithmetic and the separation a lot easier to do it that way because London is north of Paris and track SM is to the north of track SO. Concorde flies in a higher height band than most other aircraft and so a more economical cruise climb clearance can be issued due to there being virtually no other traffic to separate from . It is quite normal for an eastbound concorde to still be climbing slowly when it calls London Control, up until the time it wishes to descend. Hope that is some use to you.