David Megginson writes: > Curtis L. Olson writes: > > > I also want to see elevation at the ends of each runway if it is > > available. > > The DAFIF provides that. > > > I also want to clarify the displaced threshold information. It's > > never been clear to me how this is represented in Robin's data > > A displaced threshold is simply the distance from the actual threshold > to the start of the threshold markings. You can use that part of the > runway for beginning or ending your takeoff roll, but you cannot aim > for it on approach. There are many reasons for a displaced threshold, > but most of them boil down to the approach path -- either there are > obstacles (like trees) too close to the end of the runway, or the > airport circuit procedures bring you too close in on base (as happens > at my airport, where we have to do a slant base for 04 to stay out of > the approach path for 07). > > If you have a 3000 foot runway 09/27, and 09 has its threshold > displaced 300 feet, then you'll have white arrows: > > +---------------------------- > | || ===== > | || ===== > | ===> ===> ===> || > | || ===== > | || ===== > +---------------------------- > > followed by the runway number and the remaining 2700 feet of runway. > I could start my takeoff roll right at the beginning, but on approach, > I have to aim for the threshold markings or further. > > A stopway is marked a little differently, with yellow chevrons: > > +---------------------------- > |\ \ \ \ \ \ || ===== > | \ \ \ \ \ \ || ===== > | ) ) ) ) ) ) || > | / / / / / / || ===== > |/ / / / / / || ===== > +---------------------------- > > That surface is for emergency use only -- you cannot normally use it > for takeoff, landing, or even taxiing. > > > I see several examples of inconsistancies in the data and places > > where taxiways (or even really short runways) are used instead. > > It's possible that people got it wrong, but it's also possible that > those really are taxiways, turnaround bays, runup pads, holding areas, > and so on. > > > Would be nice if someone figured all this out, got the data > > to match, and then explained it all to me. :-) > > I hope this is a useful start.
Can we differentiate between displaced thresholds and stop ways in our current data? The current airport generator code doesn't account for either of these. When I talked to Robin, it wasn't clear if in the places where he did provide data for displaced thresholds if the overall runway length included it or not. I think the x-plane data is a mess in this respect since most of these are hand entered I believe. I propose that when we create a new DAFIFT/X-Plane database merger, we make sure that displaced thresholds and stopways are correct, and then I can update the airport generator to create them. I don't have time to work on the data base issues, but I will volunteer to do the airport generator changes if/when the data get's straightened out. Regards, Curt. -- Curtis Olson IVLab / HumanFIRST Program FlightGear Project Twin Cities [EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org _______________________________________________ Flightgear-users mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-users
