Bristol airports runway is 2011m which is more than capable of handling short to medium range ops with a 747 with limited passenger and/or fuel loads. it wouldn't be long enough for the longer routes. I think the biggest problem Bristol currently has it is the weight restriction on the parking stands. The three recently constructed stands may have a greater PCN allowing larger aircraft to park.
I've never known a B 747 land at Bristol - Filton was the nearest the city ever saw 747s and 380s on the ground.
Maybe big g or conns757 or alphagolf might know if BRS could take a 747. I've always been led to believe it would be too heavy. Another thing - would the airport have steps available to unload the passengers?
Here's the figures for a maximum weight 747 operation but it's perfectly possible to operate the aircraft on shorter runways with reduced weight, ie reduced fuel. In fact many aircraft operating at maximum take-off weight would struggle including the 737 as daft as it sounds.
Reminds me of the time about 15 years ago when we returned from Phoenix, Arizona to Bristol via Minneapolis and Amsterdam with KLM and then partner Northwest to find no hold baggage awaiting us at BRS. Wasn't the first time the notorious AMS baggage handling system had temporarily mislaid our hold baggage.
Except that this time it wasn't their fault.
The check-in agent at Phoenix had put BRU instead of BRS as final destination on our suitcases which meant they had enjoyed a visit to Belgium en route. After that I've always taken a close interest in the tags affixed by the check-in staff.
Another time we were checking in with KLM/Northwest at Denver, Colarado for a final destination at BRS. I asked the check-in agent what sort of aircraft we would be flying in on the first leg from Denver to Detroit.
"An Airbus", she replied, "built by the French".
"Partly, madam", I replied. "The British also had a hand in it; in particular the English city to which we're now flying". At least that ensured the final destination tag was correct.
From what I understand it will be fine to land there and as been mentioned it's only a short hop to MAN so should be fine to take off.
I guess with BRS having had an A330 visit in the past there would be no problem with a 744, my only thinking would be if it landed on 27 it would have to backtrack as its engines would over hang the road that runs between the taxiway and golf course.
With regards to steps I think the ones Servisair use for the 767 would fit but I'm sure who ever gets the handling job would get equipment in if they didn't have it.