KC-46...?

[PHall]

The *whole* thing full of fuel? The lift, the landing gear, the emergency return landing ..  Yuck.

Any airliner you're flying on has a "wet wing".  The top and bottom skins plus the forward and aft wing spars form the tanks.
Been that way since the fifties.

[SarDragon]

OK, fixed it.

[a2capt]

Any airliner you're flying on has a "wet wing".  The top and bottom skins plus the forward and aft wing spars form the tanks.Been that way since the fifties.

I realize that. My initial comment was in the context of "an entire cylinder of an airplane .. filled end to end with fuel". Combined with the typical need to plan for an emergency landing and dump fuel or circle around and burn it, the thing would never be able to land fully laden if it were "one big fuel tank" in the sky. Whatever. It's long been established that it's obviously not. Just an attempt at a humorous first thought from way way back.

[MercFE]

Any airliner you're flying on has a "wet wing".  The top and bottom skins plus the forward and aft wing spars form the tanks.Been that way since the fifties.

I realize that. My initial comment was in the context of "an entire cylinder of an airplane .. filled end to end with fuel". Combined with the typical need to plan for an emergency landing and dump fuel or circle around and burn it, the thing would never be able to land fully laden if it were "one big fuel tank" in the sky. Whatever. It's long been established that it's obviously not. Just an attempt at a humorous first thought from way way back.

Well, to be fair an emergency return landing doesn't care what your fuel load or aircraft weight is.  Max landing weight on our E-6B is 250,000.  However, we can take off, and return, as high as 341,000.

If you have time to dump, it's not a true emergency...

[PHall]

The "normal" max landing weight of the C-141 was 257,500 lbs, however, you could land at the max takeoff weight of 323,500 lbs if you touched down with a vertical velosity of no more than 600fpm.

This is typical of modern large aircraft.

[BuckeyeDEJ]

It shouldn't take long to get the KC-46 through development, since the platform is tried and true, and so's the technology. The Air Force made the right choice, going with Boeing. While the '46 may differ from the 767 tanker derivatives flying elsewhere, I can't imagine it's so greatly different that it'll take a decade to get it through testing.

Can't wait to see them here at MacDill, but it's going to be a while. You really have to hand it to the builders and maintainers on the C-135/C-137/E-3/E-8/et al — to think that airframe was last built for anyone in 1977 and most were built in the 1950s and 1960s, and they're all still flying strong.

New wing. New 787 style cockpit. New updated KC-10 style boom. 
That's going to be a LOT of testing to be completed before it's cleared for service.
One of the biggest delays for both the KC-767 and the KC-30 was software integration...

True, but the technology has been out there. It's not an entirely new refueling system, the avionics aren't revolutionary at this point, if at all (the 78's already flying), and if the wing isn't sourced from a previous design, sounds to me like that might be the biggest thing in testing. I don't doubt that integrating software to a different platform may have its pitfalls, but it's not like it's from-the-ground-up new stuff. Knowhatamean?

[PHall]

It shouldn't take long to get the KC-46 through development, since the platform is tried and true, and so's the technology. The Air Force made the right choice, going with Boeing. While the '46 may differ from the 767 tanker derivatives flying elsewhere, I can't imagine it's so greatly different that it'll take a decade to get it through testing.

Can't wait to see them here at MacDill, but it's going to be a while. You really have to hand it to the builders and maintainers on the C-135/C-137/E-3/E-8/et al — to think that airframe was last built for anyone in 1977 and most were built in the 1950s and 1960s, and they're all still flying strong.

New wing. New 787 style cockpit. New updated KC-10 style boom. 
That's going to be a LOT of testing to be completed before it's cleared for service.
One of the biggest delays for both the KC-767 and the KC-30 was software integration...

True, but the technology has been out there. It's not an entirely new refueling system, the avionics aren't revolutionary at this point, if at all (the 78's already flying), and if the wing isn't sourced from a previous design, sounds to me like that might be the biggest thing in testing. I don't doubt that integrating software to a different platform may have its pitfalls, but it's not like it's from-the-ground-up new stuff. Knowhatamean?

Went through the "fun" of debugging the Glass Cockpit on the C-141C. 
Sure, the airframe has been around for 25 years, but the new avionics have never been paired with this airframe.
This aircraft is getting a 787 style cockpit. That's never been done with the 767 airframe. So there WILL be systems integration problems. Trust me.
The only questions are how far behind and how far over budget will the program end up.