Saw it a number of times at air shows. Loudest engines by far.
Just refueled on the tarmac, it leaks fuel in several places. When it gets to speed, the skin expands from heat/air friction, and seals itself. Needs refueling from that fuel loss on its journey. It must nearly fall out of the sky, loping along with a KC Tanker, until its tanks are full again.
I saw them take off from Homestead AFB, just south of Miami, back in the mid-70s. State Police had highway blocked-off for miles in each direction, but we got close enough to see it clearly, thanks to a Trooper friend.