On Wednesday 24 December 2003 16:53, David Culp wrote: > > > After that I went to met up with > > a fuel tanker to try and refuel. Trying to hook up with the tanker was > > the most challenging part of the experience. I spent what felt like 10 > > minutes trying to speedup, slowdown, noseup, nosedown, left, right until > > I gave up. > > I've only refueled in 707's, but: > > Everybody has trouble at first, but aileron and elevator response are almost > instantaneous, and the control surfaces are sized and scheduled to give a > certain amount of roll or pitch rate, so that's probably not where the delay > comes from. > > When it comes to roll control the main problem is the receiving airplane's > interaction with the wingtip vortices from the tanker. I don't know if their > simulator models this effect. If it does, it could be mistaken for lack of > roll response. > > Elevator response is not a problem usually. In fact, it's usually too touchy > at first because the CG has moved aft as fuel was burned prior to refueling. > As you take on fuel the CG moves forward and the pitch control becomes less > sensitive. I don't know if swing-wing airplanes do this, as they have their > own bag of CG problems and solutions. > > Speed response is pretty slow due to the airplane's inertia and the engines' > spool-up time. The problem gets worse as the receiving airplane gets > heavier. > > The interaction of the above may cause one or more channels in your brain to > drop out for a second, which could also be perceived as slow response. This > also happens when you first try to learn an instrument scan. > > You can practice refueling to some extent in FlightGear using the AI tanker. > There is an annoying problem though, in that as you get close to the tanker > it appears to jump in 30-foot leaps (so you can't *really* practice > refueling). Also, we don't model downwash, wingtip vortices, weight change, > and CG travel. > > > > Dave > -- > **************************** > David Culp > davidculp2[at]comcast.net > ****************************
I've been wondering if that could be smoothed a bit by using a running average instead of using the raw data as it comes in. This would introduce a degree of lag, of course, depending on the data rate and number of samples. Considering that at close ranges it's pretty unusable, a half-second or less lag - say ten samples at a sample rate of 30/sec - might be acceptable. Just a thought, of course:) Happy xmas all. LeeE _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
