bildan wrote:
On Nov 20, 12:12 pm, Bruce wrote:
sisu1a wrote:
The above suggests that a tug with a highly aerodynamic airframe could
use far less HP which is why 80HP motorglider tugs seem to work so
quietly.
A tug like this:http://www.sportaircraftworks.com/ot...dynamicnew.htm
According to John Roake, turnaround on a 600m launch with this plane
averaged 4-5 minutes (takeoff to landing) and it only took 100 Euros
worth of fuel for 8 of these planes to launch a field of 60 gliders
(no other stats provided unfortunately). With efficiency like that I
bet these planes don't make a lot of noise though...
-Paul
The European "ultralight" tugs do a fine job. The Dynamic is really
quiet, fast, economical and tows well. The difference in towing behind
something like a Dynamic or Samba versus one of the heavier aircraft is
substantial. With the modern ultralight being a much better match to the
glider.

Someone said that the typical airplane engine is an excellent
transducer that converts money into heat and noise with a small,
although useful, amount of thrust as a side effect.
Indeed, consider the Wilga...

Something like a Samba or Dynamic tows smooth and at half or less of the
cost of the fossil fuel converters I am a fan. Last contest I had a
quicker ride to release behind a Rotax914 equipped Samba XL than the
preceeding run behind a Cessna 182.

The Cessna tow cost twice as much though.