> Mark,
 > My single development is designed for the Vision aircraft, Steve suggests
 > best power is between 115 and 125 HP. Weight will be under the 300 lb FF
 > limit for the single.
 > You could use a 2 rotor in a Vision and move the wings forward, Steve
 > suggested some time ago a 400 FF limit would require 4" forward travel of
 > the spar ( approx). All design changes should be approved by the
designer.
 > You could also use some weight in the tail of the plane, because of the
 > fulcrum effect the weight would be much less than the extra FF weight.
 > Some are planning 2 rotor installations.
 > George ( down under)

George,
 I'm glad you are still going with the Vision, and with the single rotor
development.  I was thinking we could get the weight/balance in line by
going with radiators (oil and water) mounted aft of the CG.   I had
thought the 300 lb FWF limit was a function of the limit of the
spar/fuselage shear web (?) design strength, not CG.  I'm probably
misremembering it.

 I want to be able to safely fly at the heavy side of the envelope
(approx 1800 lbs GW, with slotted flaps and the long wing).

Regarding moving the wing forward:  Any variation from plans introduces
complexity/delay, but it might be worth it if the alternative is
insufficient nose-up trim ability.   I'd do it if I couldn't get a
satisfactory result with battery/radiator placement.   Plus, it will
give an excuse (since I'm already "off the reservation") to explore
removable wings.  Thus the spiral of complexity widens . . .

What do you believe your single rotor engine will weigh?

Mark Waldron