"Yes, I believe that's the case, possibly as a result of criticism ten years previously when a second Whiskey Echo (a 767) was added to the fleet, the original WE (707) having been destroyed in a fatal accident at LHR about 4 years before the Trident disaster."
Or, if you've got a longer memory, there was G-ALWE, a Viscount that crashed fatally at Manchester in 1957.