In article ,
(Jeb Hoge) writes:
"Jim Doyle" wrote in message ...
Recently I've been reading about the UK BVRAAM project.

One question really:

Originally it had four mid-fuselage wings for manoeuvrability, now it has
none. This seems a little odd, since it makes sense that the more agile
missile will have a greater number of control surfaces.

Since then I've found that the new design shall use bank and turn at long
range, and in the immediate short term prior to the kill - skid turns. How
do you skid a missile at 2M+? Exhaust deflection? If anyone can explain, I'd
be very grateful!

Cheers,
Jim Doyle

And to add to this, do all missiles roll to fly with wings in a
horiz/vert (+) attitude or are there some types that fly at in an "X"
attitude? Darn things always are moving so fast that it's hard to
say, but since they obviously can come off the rail or ejectors in
either attitude, I'd assume that there's some sort of correction in
one of the two cases.

At a guess, I'd say that most post-1960 missiles try to orient
themselves into the 'X' position. in addition to allowing control
surfaces on all 4 wings (or canards or tail controls) to contribute to
the maneuver, you gain a factor of 1.4 in structural strength, since
the lift forces are spread among all 4 wings. As an example, the Nike
Herculese SAM originally started out with a '+' orinetation in flight,
and a 10 G strucural limit. Restringing the control laws to allow an
'X' orientation upped the G limit to 14, without structural
modifications.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster