Thanks John. I'll look for your book. Probably pretty pricey here in
Australia, but seems like a good one from all the mentions.

"John T Lowry" wrote in message
ink.net...

"xerj" wrote in message
...
I understand the theory vis a vis lowest L/D TAS and the power
available/power required chart, but let's say you're in flight in a
normally aspirated prop plane, your destination is blown up, your
alternate is unservicable for some reason or other and you need to stretch
the fuel you have the farthest distance possible.

What are the quick and dirty steps to working out the optimum alt and
speed? I mean in the cockpit, not in the comfort of home.

Thanks in advance.



Unfortunately, there's no quick & dirty way. The usual (Bruguet) theory is
deficient in its assumptions, and the usual cruise table is deficient in
that the wrong independent variables were selected by the GAMA committee.
At those lower speeds, you can't depend on propeller efficiency being
independent of air speed. For details and an example of what to do, see
the cruise chapter of Performance of Light Aircraft.

John Lowry
Flight Physics