Propellors vs Rotors

snipped in places...
--------------and snipped some more-----------


Wilbur and Orville used the largest props that would fit on their
airframe. In 1903 those were 8' 6" each and turned between 300 and 350
rpm depending on how hot the engine was. At an average of 8.56hp (the
engine only made 11.78hp for a few seconds dead cold), the twin props
produced an average of 96 lbs of thrust. or 11.22 lbs of thrust per hp.
Not bad on the first try.

96 pounds of thrust from 11 horse?

Actually from the 8+ horsepower. Based on 1 horsepower = 1 pound of thrust
at 315 knots, the figure sounds like a reasonable static thrust value. The
thrust may have been a little less in flight.

What did that whole rig weigh?


I vaguely remember reading something like 600 pounds, plus the pilot of
course. Orville and Wilbur were both small and slight, so the gross weight
was probably only a little more than 700 pounds...