If I recall correctly, BEA's Vanguards, which were pretty fast for turboprops, were scheduled at 1:40 on the Heathrow-Edinburgh route. Current BA A319/A320 flights are scheduled at 1:20
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I recall from the mid-1970s that the timetable allowed 70 minutes from LHR to EDI or GLA for a Trident 3, the captain always came on during taxi out to say the flight time would be 1 hour, and we were normally in the air for 50 minutes.
I don't recall how long the Vanguard took, but it allowed for a fairly decent cooked breakfast for around 140 passengers between GLA and LHR.