Heathrow SIDs
Not really a professional quwstion so asking here not ATc.
LHR SIDs havent changed materially all that much over a good few years in terms of tracks but I have often wondered that with improved aircraft climb performance the former Clacton now Brookmans Park SID doesnt mirror the Dover departures of the 27s which have a hard left of about 120 degree turn close to the airport boundary LHR and then a further turn south of Staines .
departures headed north easterly though make only a small 30 degree or so right turn for Burnham north of Slough and then another turn over a notional point, Chiltern, then head NE passing just north of Watford and on eastwards. so roughly similar but with a much wider radius for those going via BP
Obviously there is a good reason for them being different I just wondered what it is
PB