My first airline was Evergreen. We did our 747 training at United's Training Center, in the same sim (747-200) that the Air Force uses for the E-4B (Looking Glass/NAACP). My Evergreen IP was a retired Air Force E-4B pilot.

One day, we finished early and he told the Instructor Engineer working the sim panel "Hey, bring up the KC-135!" Sure enough, a KC-135R-model pops into view, one mile ahead. I was amazed at the sim detail; it even had the lower TACAN antenna that we used as a visual reference in the F-4.

He taxied in and plugged, took a few thousand pounds, and disconnected.

Knowing my background, he said (with a sly grin) "You've done this a few times....you try it."

At this point, I had somewhere between 700 and 800 air refuelings in the Phantom. I thought to myself "Well, it won't be pretty, but I can get on the boom."

I lost track of how many times I hit the tanker. The big differences were:

1. Throttle lag. The F-4 is turbojet; not much lag. JT-9Ds: lots of lag, and once the behemoth starts moving forward, lots of inertia.

2. Receptacle location. In the F-4, top of the fuselage, roughly over the aerodynamic center. It means when the nose is raised or lowered, the receptacle doesn't really move.

Receptacle in the 747: in front of the windscreen, about 100-120 feet in front of the aerodynamic center. Move the pitch half a degree? The receptacle just moved 1-foot vertically.

3. Inertia. Big airplanes have inertia in pitch, roll, and speed. Once started, hard to stop.

I had watched a KC-10 get refueled by a KC-135A on an ocean crossing once (I was in the F-4). I couldn't believe how much the -10 was moving, and I swear I could see the fuselage flexing.

I never did get a contact. I had a new respect for refueling a heavy.