On Mon, Apr 6, 2009 at 12:31 PM, Onno Meyer <[email protected]> wrote: >> Minimum speed for 30 mph, take-off run of 30 yards, > > v = speed > a = accel > t = time > d = distance > > So we have roughly v = 13 m/s after d = 27 m. > > v = a*t <=> v/a = t > d = 0.5 a t^2 <=> d = 0.5 a (v/a)^2 <=> d = 0.5 v^2/a <=> a = 0.5 v^2/d > a = 0.5 * 169 m^2/s^2 / (27 m) = 3.12 m/s^2 > > Assuming constant acceleration, the autogyro would need > an acceleration of roughly 7 mph/s for that takeoff run. > Not surprisingly, Vehicles agrees. > >> landing roll of 3 yards. > > decel 70, or roughly 3.5 Gs. That is way beyond anything > Vehicles would allow, unless it was below 30 mph prior > to the landing. >
Which it almost certainly was. Autogyros have pretty friendly stall behavior. When an airplane stalls, the lift drops abruptly to close to zero, so the plane falls at 1 g, until it hits the ground, or it's got enough air speed to generate lift. As an autogyro slows down, its rotor produces less lift. When it produces less lift than necessary for level flight, the autogyro falls, but the lift produced by the rotor doesn't fall to zero, it's just less than what's needed to keep it in the air. So the autogyro falls with an acceleration much less than one g. Autogyros are probably not easily coverable by the rules in Vehicles, as they're very different beasts than fixed wing aircraft, or helocopters. -- David Scheidt [email protected] _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
