David Megginson wrote: > 1. According to the author, at least, differential braking is bad form > while taxiing the DC-3; you should use differential power instead > except for very tight turns.
I'll buy that. But working dual throttles during the takeoff and landing rolls can't possibly be a good idea, right? In that regime, you're still stuck with rudder and braking only. During the landing roll (with no significant prop wash), you're stuck with braking only. > 2. Maintaining a straight heading is hard during the early part of the > takeoff roll, but the text describes S-curves rather than violent > spinning as the problem for inexperienced pilots. Is that with or without braking being applied? I can confirm that I execute lots of S curves during takeoff in the DC-3 when using the brakes method. It only spins violently when you try to correct yaw divergence with a flapping rudder. Just to clarify what I said earlier: the reason that it looks like a rudder problem is that turning the plane a "little bit" with the rudder is possible. But once it is pointed little bit away from the velocity vector, it begins turning *farther* away very rapidly. If you don't correct this immediately, the aircraft will rapidly be so far out of whack that the rudder is incapable of correcting the yaw. Thus, what started out as a tiny rudder input diverges into a ground loop. But it's caused by a *lack* of rudder authority to correct the problem, not by too much authority causing it. Does that make more sense? Also, recognize that implementing prop wash would have the effect of increasing rudder authority during the takeoff (but not landing) roll, which will also help. > Locking the tailwheel should help a lot, but we'll also have to make > sure that the tailwheel has the right amount of authority. Hey, now that's really good information. This would *definitely* help with directional stability. You can lock the tailwheel by simply removing the castering="1" bit from the gear definition. This could be pretty easily made settable at runtime via a property. You don't have to worry about the skidding authority of the wheel -- skidding friction (to first order, anyway, for tires that aren't melting) is the same for wheels of all shapes and sizes. I really should read through this site more carefully. It's got lots of good stuff. The fantastic quote in question is: >> CAUTION: THE TAIL WHEEL LOCK MUST BE LOCKED DURING TAKE OFF AND >> LANDING. Sounds like good advice to me. I'm not at home right now; can someone remove the castering setting from the dc3.xml file and try it? If this is the solution, then I'll add a property-based control for castering tonight. Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
