Concorde – An alternative view.
I have to admit that as a UK ATCO that has to control Concorde (London Centre) I’m not overly ecstatic about its return.
Fantastic though it may be, it’s a pain to control both outbound and inbound.
Outbound whilst initially it has a low rate (angle) of climb as it accelerates, once the speed builds up, it climbs around 4000 ft/min to it’s initial subsonic cruise around FL 260-280, and needs plenty of warning as it doesn’t like to have to stop off at intermediate levels.
To get to it’s supersonic acceleration point over the Bristol channel, it has to cross through the London TMA inbound flow, effectively going the wrong way down a one way street.
Once given its clearance to climb and accelerate to supersonic speeds it won’t take any vectors, everything that’s in its way has to scatter. Trying to decide what is in its way is not as easy as you might think. London centre doesn’t have ground speed read out on the radar (can you believe that!) so as it starts it acceleration from subsonic to 1500 mph, working out if traffic a 100 miles away crossing its track is going to come close can be tricky. Especially in view that when Conc first started it was unusual to have traffic above FL 370, whereas now FL410 is common place.
Also because the British and French Concordes depart to KJFK at similar times, much brainpower is engaged even whilst the aircraft are on the ground to decide if they both can have the optimum oceanic track. As they cruise so high above the jetstreams they have a fixed route system. We need 15 mins between them at 15 degrees west, (from memory, will re-read procedures before next shift, honest), if we don’t have it, amazingly the Air France Conc takes track “SO” which involves a longer routing.
Out of interest although we clear the aircraft to FL600, it never actually gets there with a commercial load, but cruise climbs its way across the pond. Coming eastbound towards the UK it’s usually passing around FL573 going towards FL590 when it asks for descent.
Inbound to UK it fairly quickly drops to FL 370 and subsonic speeds and for a while it’s fine. The problem then is that it likes to leaves its descent as late as possible (we all know fuel is tight), whilst converging towards a two-way air-route. All westbound traffic on this Air-route between Flight levels 150-350 are potential conflicts, and our normal solution of parallel headings can’t be applied until it hits the Air-route. Trying to think of a safe initial level to descend to isn’t always easy.
Finally, it motors in at around 370 kts indicated, which is fine if you want to overtake traffic, but trying to slow it down is next to impossible.
I would like to say that my heart lifts when I hear Conc getting airborne (it’s very audible even from London Centre about 5 miles from Heathrow, the only aircraft I can hear take-off), the reality is I start scouring the radar for traffic hundreds of miles west of the UK trying to workout which are best re-routed and which I’m likely to miss.
I’m just thankful there are so few of them.
I’d be interested to know how the controllers in New York centre deal with it, are you glad it’s back?