Interesting bit of nostalgia for me this thread .
I remember from my enthusiast/spotter days hearing Clipper flights cleared on as I recall ' a non standard polar departure crossing Epsom at 2000 and Biggin at 4000. I thought these were off 09R as it was because a heavy 747 turning for Epsom off 28L/R would probably have scared everyone in Staines to death but I may well be wrong. I also remember the same aircraft getting a 'non standard Lyneham west departure -to leave airways west of Lyneham'. Was that for the same reason
I assumed these were due to the early 747s being unable to climb as required by SIDs
I ddint know anyone used circling departures at LHR-some years later Iwas on an Air France 747-100 Combi departing beijing for Paris and that performed an enormous circle overhead the airport in order to gain height to cross the mountains north of the city-quite exciting .
On the subject of long trips South African had a Mondays only 747-100 departure direct to Jo'burg- pretty impressive if you stood at the departure end of 28L and watch them rotate just before the block 79? intersection
Happy days-at least if you lived near LHR and put up with the noise you could watch the fun in peace without fences and security
PB