Vance Jaqua wrote:

Why is 393 pounds of thrust out of the fixed pitch
prop hard to believe? :-)

Because it is taking the O-320 Lancair 27 seconds
instead of 9 seconds
to get to 100 feet per second with a fixed pitch
prop. That is why 393 pound
of thrust out of the fixed pitch prop is hard to
believe regardless of the
minor change in disk loading. These are real
measured numbers ostensible.

Where did I go wrong explaining this? :-) Is my math
wrong someplace?

Paul Lamar

Your math is not wrong -
The Lancair chart you are using is bogus! just ask any
Lancair 320 owner with a fixed pitch prop. they are
way better than that. You could not take off at Santa
Paula with that kind of performance.
Our original Cruiser with a fixed pitch prop on a 180
Lyc could not be held by the brakes at full throttle -
27 seconds when you are running down a runway is an
eternity - Cessna 152 's are off quicker than that -
those guys are purely trying to sell you a $7000 prop
- Vance

OK Vance we have our feelers out for real world data. We shall
see what numbers we get on the takeoff time and do the math.

Paul Lamar
 
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