Scott, I'm curious what the numbers look like cruising at max endurance in the
360... set the AOA at L/D max (green bar w/ the "x" in it), and then set the
power to maintain a constant altitude.  I wonder where the airspeed winds up
and what the endurance is at that setting.  Next time you have a chance...
Thanks....

Marv,

 

All references I have state that, for recips, generally max endurance is 75% of the max range velocity (no wind) which is obtained at max L/D (for reasonable GA aircraft).  I will try to get both at power settings low enough to go LOP.  While our reflexed wing is designed to reduce drag, I may have to take it out of reflex for the max endurance test.  Also, I will try Lindbergh's claim that high MAP, low RPM is more efficient than low MAP, high RPM for the same power setting.  Then we must consider another value of AOA since the angle of attack for max L/D may vary with the weight of the airplane - and that will happen as fuel is burned.  Say a fully fueled 320 weighed 1800# and reached 1620# by burning off 30 gallons (180#) of fuel - By the time it reached that 10% reduction in weight there would be a 5% decrease in velocity, a 15% decrease in the power required and an 11% increase in range (if you started at that new weight) when the max L/D condition was maintained for the flight.