"Guy Alcala" wrote in message

Do you happen to know why the -300s have less drag? Offhand I'd expect
the
opposite, given the larger wetted area.

Better fineness ratio.


Thanks for the info. I suspect FL330 is probably a good 8,000 feet higher
than
F-111s are likely to be cruising, or loaded F-18s. Certainly, that's far
higher
than the typical refueling altitudes the US uses in combat (FL210-250
being
quite typical), and most trans-oceanic ferry flights by U.S. fighters also
seem
to be done at FL250, presumably to prevent the need for constant climbs
from and
descents to refueling altitude.

I know. I chose the figure as it was about as high as they would reasonably
go at max weight. None of the engines are at their best when kept down low
though. I was a little surprised at just how well the PW compared in that
circumstance.

JB