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What might have been. A few were ordered by the Shah of Iran's Air Force in the 70's.

Man, the City of Everett was used for everything; similar to the Dash 80. Workhorses.

A tanker in TWA colors. Awesome.

One of my favorite "could have beens", along with the YF-12A and the XB-70.

How about this one?

What about wake turbulence? How is it possible that wake turbulence from a 747 can bring down an Airbus yet it was thought that a jet can get within 40 feet of it and refuel?

The wing tip vorticies are the real bear there. There is a rumble, but it has been demonstrated. The heavier the airplane, the better the ride.

Also, the faster the aircraft the less induced drag and therefore the less wake turbulence. The receiving aircraft is between the wingtip vortices and below most of the other wing/fuselage interference wake turbulence.

It actually works the other way, too. A large aircraft like a C-5 coming up behind a KC-135 will cause the rear of the KC-135 to be pushed upward by the bow wave of the C-5 and the KC will have to retrim.

How about the tail engine of a KC-10 hitting the T-tail of a C-5?

GQfluffy wrote:How about the tail engine of a KC-10 hitting the T-tail of a C-5?

You've still got quite a bit of height difference, the KC-10 is at steady-state cruise thrust, not takeoff thrust so there's not much speed differential between the air coming out of the engine and the air mass the aircraft are passing through, and it's still more or less 300 feet back from the exhaust of the KC-10 to the tail of the C-5. It's just not a problem. Although I'm sure the fuel would be a little sweeter coming out of a KC-747.

Heh...laying in wait.

You so sure about the height difference?

This seems to be the best picture I can find-

Looks like about 75-100 feet down to me, combine that with the 15-20 feet above your head up to the engine and I'd say it's just not much to worry about.