ISTR is was nothing normal. Supposedly RR kitted it out with good engines, it had special ATC clearances throughout, was towed to the runway (?), minimal load etc. Certainly not a commercial flight as we know it. Apparently it was touch and go whether the flight would be abandoned short of its destination due fuel.
Even the fuel was special. And yes, the aircraft was towed to the runway and only started its engines after that.
It would have been a pity, though, if after all of that planning and preparation, the stronger-than-forecast winds had led to the flight having to divert for fuel reasons.