Dave Perry wrote:
> Sent: 29 July 2004 01:48 > To: [EMAIL PROTECTED] > Subject: [Flightgear-devel] Taildragger takeoffs and landings > > > David Megginson wrote: > > >This problem has little effect on normal flight, but it > matters a lot > >for > >the landing and takeoff rolls of taildraggers -- without it, > they have an > >unrealistic tendency to nose over. > > > I have been tied up with an upgrade to SuSe 9.1 and wanted to > comment on > the tail dragger set up discussion. > 1. I updated CVS last night and the changes to the J3 Cub make it > impossible to do a full-stall 3 point landing. > 2. It is not true that a wheel landing should end with applying full > down elevator. In fact, you want to be almost at zero decent > rate when > the mains touch and then a little forward pressure is usually > required > to keep the immediate slight increase in angle of attach from putting > you back in the air, since you have not yet stalled. > 3. In a real cub, it takes very little relative wind to keep > the tail > up. So in a head wind of say 10 knots, you can lift the tail with > forward pressure as soon as you apply power. I have seen pilots hold > the brakes, apply power and lift the tail at zero ground speed. > > I really thought the way the cub was in fgfs before these changes was > very realistic. I would do 4 touch and goes in the length of 29R at > KSFO with all of them wheel landings. Were you really having trouble > with nose overs with the cub? I have real hours hours in Stinson 108 > Voyager, Taylorcraft (almost identical to the cub), Cessna > 140 and 170, > Luscome Silverair, Citabra, Champ, and probably other tail > draggers that > I have forgotten. > > Also, even though it is usual to have the CG slightly ahead > of the wing > center of lift so the tail plane is providing negative lift in level > flight, many aircraft when fully loaded have the tail plane providing > some positive lift. I flew my Comanche 250 from Denver to > Duluth, MN, > on to DSM, and back to Denver with 4 passengers and baggage > to the point > that I only could fill the inboards to stay below 2900 lbs > (max gross). > The trim was very much different at all speeds. With just two in the > front seats and no baggage, the trim for approach is much more up > elevator trim than at cruise (tail plane has negative lift). > But fully > loaded, the trim changes very little as you slow up for > approach. This > could be because the CG is more aft fully loaded, so the tail > plane is > carrying some of the load. > > I have never been totally happy with the DC3 ground handling. It has > always been too slow on acceleration in bringing the tail up and it > would try and fly with the tail still on the ground and if > you tried to > get the tail up with forward pressure, it was way too easy to > get in a > porpoise. Moving the CG as far forward as possible helped and > increasing the horizontal stab effectiveness also helped. I had also > made the length longer. The real DC3 tail came up very quickly, very > similar to the cub in reality. I have not flown the fgfs DC3 > since the > recent changes. I will try it and then comment some more. > > Good discussion, Have you tried the Spitfire yet? I would be grateful for any comments you might have. Regards, Vivian _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
