On Fri, 30 Apr 2004 15:29:22 -0000, "karel adams"
wrote:

Does this imply that a slow & sturdy aircraft does not
profit as much from the composite advantages
and hence can better be built from aluminium?
And that likewise a sleek fast tourer better be composite?

KA (learning slowly)

That sounds pretty right Karel. Real world laminar flow did not
really begin to happen until the advent of super smooth composite
airplanes. Laminar flow isn't something an airplane that does not
cruise faster than 130 kts or so needs.

The P-51 Mustang is well known as one of the first fighters to make
use of a laminar flow wing. Many ascribe it's long range and high
speed to the wing design. In fact it very likely did (then and now)
not achieve much laminar flow for several reasons. It was discovered
that even slight imperfections in the wing caused the laminar flow to
trip to turbulent. Dents, scuff marks from ground crew, patches, butt
joints in the aluminum sheeting all caused the laminar flow to trip to
turbulent. In addition, it was found that the area within the
propwash was not laminar. The Mustang had a mighty big prop that
washed about a quarter to a third of each wing.

So achieving laminar flow isn't easy. Getting attached laminar flow
is one of the big reason (as I understand it) why Burt Rutan designed
the rear engined EZ series of airplanes.

Corky Scott