Originally Posted by
ETOPS
I took part in those trials - in 1996 ! The type was B737-436 and the route was Aldergrove to Heathrow. The reason was the Boeing FMC had an "extra" page titled RTA - Required Time of Arrival. Departure clearance from BFS contained a time over BNN which was entered as RTA/BNN which would automatically adjust the cruise Mach number. We found the problem from the outset as cruise speeds below or above normal limits were being demanded
I understand the Lockheed Tristar had that feature from 25 years beforehand, although it could be set for all the limits to be complied with as well. It was apparently accurate for arrival time at a fix to the second. Designed, by the way, principally by someone from Hatfield who Burbank tempted away when Hawker Siddeley gave up developing the Trident further.
Not sure but there is currently Dash 8 cruising at 24,000ft 390kts and a flight time to EDI of 1hr 20. Getting in 20 mins early.
I once left Belfast City on consecutive runway departures with a colleague, he to Heathrow on a super-whizzy jet A320, me to London City on a trundling propeller Q400. I landed, exited, got in car, drove the short distance home, walked into house, phoned him up ... he was just waiting to disembark at LHR, after what sounded like n times round Bovingdon.