"David O" wrote in message
...
Big John wrote:

Also in cruise you would climb several
hundred feet above your cruise altitude and in a shallow descent back
to that altitude pick up 10 mph + which the bird would hold if you
were careful and held a constant attitude. Was told (bar talk) that
was a characteristic of a laminar flow wing????

With all due respect, John, I rather think it is a characteristic of
people's ability to fool themselves. For my part, I'll believe that
Mustangs and/or Mooneys have a cruise "step" when an organization such
as NASA or CAFE documents the phenomena.

The following post by Dr. Philip Bridges of the Aerospace Engineering
Department at Mississippi State University echoes my sentiments on the
subject,

http://tinyurl.com/x48p

For the record, Dr. Bridges has recently retired from the ASE
department at Mississippi State.

Regards,

David O -- http://www.AirplaneZone.com

WRT the "step" on powered airplanes, I wouldn't dast say. But Richard
Johnson, in his testing of sailplanes, has documented "bi-stable" polars --
measurably different drag at the same constant airspeed, depending on
whether the airspeed was approached from above or below. IIRC, he attributed
the difference to the formation (or not) of a laminar bubble at the
transition from laminar to turbulent flow. Gliders typically have lower
Reynolds numbers than power planes, so this probably doesn't apply to the
P51 and the Mooney.

Tim Ward