X-Mozilla-Keys:                                                                                 

Ron Caraway in the Cosman at 149 smoked the

second place

Kim Prout in the Europa at 133 in the 90 HP class

despite

Ron haveing only 65 HP. That Cosman is a slick

little

airplane. 

We're thinking that Ron should solve his gear
flutter problem and wrest
Mike Arnold of his record.  Ron won the race on 2/3
throttle.  He's got
a resonnace in the prop/engine/gear that shows up at
2050 rpm.  
R&D time

Kevin Walsh wrote:

Based on my numbers (from the old John Roncz
spreadsheets) Mike Arnold would still have him beat.
If you run the numbers for the Cosman at 2/3 power
(44HP) and reasonable numbers for prop efficiency,
etc. you get an equivalent flat plate drag area of
1.047 ft^2.  A very respectable number, but much more
than the AR-5 at 0.88 ft^2.  In order to get the
Cosmon past the AR-5 you'd likely have to push it with
78.5 HP.  Not an unreasonable amount, but it does
point out that the Cosmon is a less efficient airplane
than the little AR-5 with a 65hp Rotax.

If anyone is really interested, the AR-5 is for sale,
and you could stuff your favorite 1 rotor 100HP mill
in there and probably run the gates at around  239mph.
 Now a plane like Lars Giertz's ill fated V-max Probe
pushed by a 100hp single rotor just might be the
ticket you need to push past 300mph.

Kevin Russert Walsh
Process & Equipment Development Engineer
Inhale Therapeutic Systems, Inc. (NASD:INHL)www.inhale.com

 
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