On 8-Aug-2006, wrote:

Yeah, I really meant the parrot which is about 115 knots with 120 hp.


--If you believe in miracles. By the laws of aerodynamics, for a given
airframe (i.e. same drag characteristics) the airspeed in level flight will
increase as the cube root of the increase in power. According to the cited
webpage, the Parrot cruises at 75% with a 100 hp engine at 115 mph (100
kts). They PROJECT that 75% cruise speed will be 130 mph(113 kts) with a
120 hp engine. But according to the cube root law, you would need to
increase engine size to 144 hp in order to get 75% cruise to increase from
115 to 130 mph. In order to do it with only 120 hp you would have to have a
miraculous increase in propeller efficiency (not likely, and anyway you
can't do better than 100%) and/or a huge reduction in cooling drag (also
unlikely). More likely, 75% cruise with the 120 hp engine will be around
122 mph (106 kts).


-Elliott Drucker