Henry J Cobb wrote:

sameolesid wrote:
Reengineering the 7E7 for this role will entail some serious costs and
time. The smarter move for Boeing would be to invest in the BWB.

There's a win-win here.

http://seattlepi.nwsource.com/local/...%2 0New%20747
This time, Boeing is gauging interest in the 747A - for "Advanced" -
that would be slightly larger and more technically advanced than the
most current model, the 747-400ER. The plane would blend technology
from the 7E7 with the 747's size in a package Boeing claims would be
far cheaper to fly than the A380.

If the USAF would sign a contract to buy six KC-747A tankers a year for
the next decade (displacing the F/A-22 in the budget), each with one
center boom/drogue and a pair of wing mounted drogues you'd get a tanker
that carries a huge amount of fuel while flying very efficently thereby
doing the job of two old tankers while helping Boeing start a brand new
production line rather than getting some dead end airframes from an old
production line.

Why on earth would the USAF buy 747 tankers when they're far larger than the "takes up too much ramp
space" A330s that they rejected in favor of the 767? There's a nice graphic here showing the
relative sizes of the 767 and A330:

http://www.airpictorial.com/pages/Boeings767Tanker.html

and the 747's considerably bigger than the A330. Not to mention that the USAF rejected a KC-747 in
favor of the KC-10 way back when, as the 747 was larger than they needed. A 747 is an excellent
deployment tanker (what Carlo Kopp calls a Strategic tanker), but it takes up a lot of space on the
ramp and requires long, strong runways, while providing no more refueling stations than a far
smaller 767 or 135. The Air Force is looking for a replacement for the latter, not their KC-10s.
The maximum number of refueling stations per a/c per airfield is what's important to them for the
tactical tanking role, _not_ which a/c has the largest fuel offload per plane.

This is aside from the fact that the a/c might be too long to have a boom (that's why Boeing went
with the 767-200 rather than the -300; the latter would be too limited in rotation angle with a
boom, increasing t/o and landing distances. And then there are serious doubts that the a/c will
ever get built -- as the article mentions, 'new', larger versions of the 747 (-500, -600, 747X that
I can remember) have been mooted by Boeing for the past 10 years at least, with little customer
interest. I expect the 747 production will continue to wind down, but it hasn't done badly for an
a/c that was originally expected to only carry passengers for 5-10 years or so (the SST was going to
take over from it in that role) before being converted into a freighter. It makes an excellent
freighter, but there are plenty of used -200s, -300s and -400s out there to convert.

Guy