On Fri, 09 Jan 2004 18:43:43 GMT, "Gary Drescher"
wrote:

"Roy Smith" wrote in message
...
"Gary Drescher" wrote:
(The calculations should be made with regard to CAS rather than IAS,
but the difference is usually small.)

Careful about that. CAS is usually very close to IAS near cruise, but
at the low end of the scale, they may differ significantly.

True. It depends a lot on the aircraft. Lately I've been flying Arrows,
for which the discrepancy is tiny even near stall speed. But that's not
always the case.

Right! For a C-172 (most models/years) the error gets pretty large at Vs0
-- 50 KCAS = 33 KIAS. That difference is certainly NOT trivial.


--Gary