[Flightgear-devel] Test Message - Please Disregard
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Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB
Cameron, If the simulation is accurate the delays are due to the aircraft inertia and not control system delays. Hydraulic controls don't have a humanly discernable amount of delay. Simulators have their own delays too, the time it takes a signal to get through the circuit from the control to the computer and them to be processed in the next frame., but this is on the order of 50-100 milliseconds. Most of what you were seeing was due to inertia in my guess. Merry Christmas Nickolas HeinMorgantown WV - Original Message - From: Cameron Moore To: FlightGear developers discussions Sent: Wednesday, December 24, 2003 12:39 AM Subject: Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB * [EMAIL PROTECTED] (Jon Berndt) [2003.12.23 19:02]: As for the software side of the sim, it looked and felt a lot like FlightGear+JSBSim. There were some bugs: Hmmm... ;-)Hehe. I didn't mean to imply that JSBSim has bugs (though it does ;-).I meant that the handling was about the same in both.One question though. I mentioned trying to line up with a fuel tankerand how the delayed movement was throwing me off. My guess is that thisbehavior was due to slow control surface movements. My question is ifJSBSim simulates control surface movement speeds (excluding the flapswhich do) or is the control surface deflection always exactly equal tothe control input?-- Cameron Moore[ Why is a carrot more orange than an orange? ]___Flightgear-devel mailing list[EMAIL PROTECTED]http://mail.flightgear.org/mailman/listinfo/flightgear-devel ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
Cameron Moore wrote: Everyone in my office it tired of hearing about it, so I thought I'd turn to you guys. I had a chance to go fly in a B-1B flight simulator as part of a tour at Dyess AFB today. (See below for some links[1] to Wow, a full size B-1 simulator. Now *that* must be impressive! Anyway, it was a fun trip. If any of you ever get a chance to climb into a big sim like this, go for it. Merry Christmas! I second that. Every time I get a chance to step into one of those simulators I have a great time. It's definitely worth it. Erik [1] http://www.kgwings.com/fieldtrips/dyess/sim1.JPG http://www.kgwings.com/fieldtrips/dyess/sim2.JPG http://www.kgwings.com/fieldtrips/dyess/b1sim.JPG ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB
One question though. I mentioned trying to line up with a fuel tanker and how the delayed movement was throwing me off. My guess is that this behavior was due to slow control surface movements. My question is if JSBSim simulates control surface movement speeds (excluding the flaps which do) or is the control surface deflection always exactly equal to the control input? We don't currently model forces that oppose control surface movement, nor do we model actuator lags - though both would not be difficult given the right information. The effect you are seeing is likely related to the size of the aircraft - it's moment of inertia. Currently - for all but the X-15 - the actuator motion is equal to the control system command to that aerosurface. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB
Hinge moments for control surfaces probably have something to do with it, The control system would compensate for that, pushing the aerosurface to give the desired aircraft body rate. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] TaxiDraw-0.1.1 available
TaxiDraw-0.1.1 is now available from: http://www.nottingham.ac.uk/~eazdluf/TaxiDraw-0p1p1-w32bin.zip Windows binary [383K] and http://www.nottingham.ac.uk/~eazdluf/TaxiDraw-0p1p1-src.tar.gz Source [85K], requires wxWindows to compile (wxGTK-dev on Linux). *** Summary of changes from 0.1.0 to 0.1.1: A list of taxiways can be brought up at the side by pressing 'z'. This shows the taxiway ordering, taxiways at the top of the list are rendered on top of those further down the list by both TaxiDraw and Terra/FlightGear. Taxiways can be moved up or down the list with numpad 8/2. You need to save afterwards for the changes to be persistant. The list can be scrolled with numpad 9/3. A 'T' number for each taxiway is displayed in the list - this may be non-unique, and is only persistant during one session. It exists purely to help show what is happening when a taxiway is moved up or down the list. In order to allow a quick check of the rendering order, a marking mode can be toggled using the 'm' key. In this mode taxiways are drawn with outlines to show the rendering order. When the list is showing, selected taxiways are also overdrawn. The program local is now set to POSIX at startup to fix a bug where atof would return an int for some locals (apparently ones that use a comma for thousands separation). Thanks to Ivo for finding the bug and the fix. Background images are no longer scaled during zoom when not displayed. The stackdump with extreme zoom out is fixed. An image path (or filename if in same directory) can be manually added to the calibration, and when the cal is loaded it should load the image. X and Y of the top left corner of the image can be manually specified in the cal if known, this overrides the lat and lon if present. Use capital X followed by a space and then the number, ditto for Y. [LINUX ONLY] - USGS images can now be fetched from within the program. To use this, open a US airport and click background-fetch image. Draw a box around the image as prompted on the status bar, and the images will be fetched, tiled and calibrated (hopefully!) as long as wget and imagemagick (montage) are on your system. This is very beta - it WILL overwrite anything with the same name as the jpegs in the working directory, so if your wedding photos are labelled S10X1345Y56893Z16.jpg etc then back them up or don't use it. Also overwrites ICAO.jpg eg KDFW.jpg. YOU HAVE BEEN WARNED Not compiled into the windows binary due to the probable lack of wget and montage, and since montage often fails to find the downloaded images, seems to be some confusion about the working dir. This feature seems to do a perfect calibration on larger airports, but smaller airport positions often disagree between the data and USGS. Not much I can do about that! Remember to save the calibration - it doesn't do it for you. Probably a few other bits and pieces that I can't remember! Happy Christmas everyone, Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] Dynamic scenery texture loading
On 12/19/03 at 8:52 AM Norman Vine wrote: Ah.. the light shines in Britain too :-) http://baron.me.umn.edu/pipermail/flightgear-devel/2002-August/009981.html LOL, I seem to have come up with an almost word for word reproduction of your ideas. It wasn't intentional, honest guv :-) Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Dynamic scenery texture loading
On 12/19/03 at 10:07 PM Paul Surgeon wrote: On Friday, 19 December 2003 13:23, David Luff wrote: The second thing is that I'd like it to be able to page textures in and out Oooo ... ... *rubs hands gleefully* Don't get too excited, and don't stop coding if you're already at it, this is going to take me a loong time! This is one feature I would love to see implemented but it's going to be a major change. The basic paging algorithm shouldn't be too hard but the mipmapping/scaling of images and video memory management is going to be fun. The more I look at it the more I realise why no-one has just done it yet. Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] TaxiDraw-0.1.1 available
On 12/24/03 at 3:18 PM David Luff wrote: Probably a few other bits and pieces that I can't remember! Oh yeah, like adding some rudimentary instructions to the help. Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] TaxiDraw-0.1.1 available
David Luff wrote: On 12/24/03 at 3:18 PM David Luff wrote: Probably a few other bits and pieces that I can't remember! Oh yeah, like adding some rudimentary instructions to the help. That's not a bad choice ;-) Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB
Nick wrote: If the simulation is accurate the delays are due to the aircraft inertia and not control system delays. Hydraulic controls don't have a humanly discernable amount of delay. Simulators have their own delays too, the time it takes a signal to get through the circuit from the control to the computer and them to be processed in the next frame., but this is on the order of 50-100 milliseconds. Hydraulics *do* have a maximum slew rate, though, which might be what he meant. On a Cub, you can snap the stick from one side to the other and the ailerons actually move. With a hydraulic system, you can only move the stick so fast; the fluid in the pipes needs time to flow, and the pumps can only handle so much volume at once. There is a transition-time attribute in YASim that you can use to specify speeds for surface deflections. I added it for flaps, obviously, but I think I've seen that Lee has used it for this kind of applicaiton. Andy ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] TaxiDraw-0.1.1 available
David Luff wrote: TaxiDraw-0.1.1 is now available from: http://www.nottingham.ac.uk/~eazdluf/TaxiDraw-0p1p1-w32bin.zip Windows binary [383K] and http://www.nottingham.ac.uk/~eazdluf/TaxiDraw-0p1p1-src.tar.gz Source [85K], requires wxWindows to compile (wxGTK-dev on Linux). Excellent. I think that taxidraw is useful (and used) enough now that it deserves its own home page. Right now, there is no URL where I can come back in a few weeks and check if there's a newer version, read online docs, look at screenshots, etc. How about it, Dave? You've done great work, so your project deserves something like http://www.nottingham.ac.uk/~eazdluf/TaxiDraw/ All the best, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] Merry Christmas
Merry Christmas from Minnesota. I just received this so I thought I'd pass it along in case other's hadn't seen it yet ... Curt. -- Curtis Olson HumanFIRST Program FlightGear Project Twin Citiescurt 'at' me.umn.edu curt 'at' flightgear.org Minnesota http://www.flightgear.org/~curt http://www.flightgear.org Twas the night before Christmas and out on the ramp, Not an airplane was stirring, not even a Champ. The aircraft were fastened to tiedowns with care, In hopes that come morning, they all would be there. The fuel trucks were nestled, all snug in their spots, With gusts from two-forty at thirty-nine knots. I slumped at the fuel desk, now finally caught up, And settled down comfortably, resting my butt. When the radio lit up with noise and with chatter, I turned up the scanner to see what was the matter. A voice clearly heard over static and snow, Called for clearance to land at the airport below. He barked his transmission so lively and quick, I'd have sworn that the call sign he used was St. Nick. I ran to the panel to turn up the lights, The better to welcome his magical flight. He called his position, no room for denial, St. Nicholas One, turnin' left onto final. And what to my wondering eyes should appear, But a Rutan-built sleigh, with eight Rotax reindeer! With vectors to final, down the glideslope he came. As he passed all the fixes, he called them by name: Now Ringo! Now Tolga! Now Trini and Bacun! On Comet! On Cupid! What pills was he takin?? While controllers were sittin' and scratchin' their heads, They phoned up my office and I heard it with dread. The message they left was both emphatic and dour; When the fat guy pulls in, have him please call the tower. He landed like silk, the sled runners sparkling. And I heard, Left at Charlie, and Taxi to parking. He slowed to a taxi, turned off of three-oh, And stopped on the ramp with a Ho-ho, ho-ho. He stepped out of the sleigh and smiled at my shock, As I ran out to meet him with my best set of chocks. His red helmet and goggles were covered with frost, And his beard was all blackened from reindeer exhaust. His breath smelled like peppermint, gone slightly stale, And he puffed on a pipe, but he didn't inhale. His cheeks were all rosy and jiggled like jelly, His boots were as black as a cropduster's belly. He was chubby and plump, in his suit of bright red, And he asked me to fill it, with hundred low-lead. He came dashing in from the snow-covered pump, I knew he was anxious to be drainin' the sump. I spoke not a word but went straight to my work, And filled up the sleigh, without being a jerk. From the restroom he returned with a sigh of relief, Then picked up a phone for a Flight Service brief. And I thought as he silently scribed in his log, These reindeer could land in an eighth-mile fog. He completed his pre-flight, from the front to the rear. Then he put on his headset and I heard him yell, Clear! And laying a finger on his push-to-talk, He called up the tower for clearance and squawk. Take taxiway Charlie, the southbound direction, Turn right three-two-zero at pilot's discretion. He sped down the runway, the best of the best, Your traffic's a Grumman, inbound from the west. And I heard him proclaim as he climbed through the night, Merry Christmas to all! I have traffic in sight. - Anonymous - ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
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 ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
RE: [Flightgear-devel] Dynamic scenery texture loading
David Luff writes: On 12/19/03 at 8:52 AM Norman Vine wrote: Ah.. the light shines in Britain too :-) http://baron.me.umn.edu/pipermail/flightgear-devel/2002-August/009981.html LOL, I seem to have come up with an almost word for word reproduction of your ideas. No problem, in fact I just borrowed the idea myself from the more general concept of 'acquisition' http://www.zope.org/Members/Amos/WhatIsAcquisition Cheers Norman If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it. -- Thomas Jefferson ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
David Culp wrote: 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). That sounds like a bug. My reading of the AI code indicates that motion should be continuous, no? Also, we don't model downwash, wingtip vortices, weight change, and CG travel. Actually, weight change and CG travel due to fuel load *are* modelled. With YASim, at least, there is currently no way to get the new fuel state into the FDM (it wants to own the fuel load instead of reading it out of the property tree). But that's a really easy thing to fix if someone wants to work on this. Andy ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
One question though. I mentioned trying to line up with a fuel tanker and how the delayed movement was throwing me off. My guess is that this behavior was due to slow control surface movements. My question is if JSBSim simulates control surface movement speeds (excluding the flaps which do) or is the control surface deflection always exactly equal to the control input? I think It has more to do with moving multiple tons of steel and aluminum with a tiny little control surface. g. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Merry Christmas
Curtis L. Olson wrote: Merry Christmas from Minnesota. I just received this so I thought I'd pass it along in case other's hadn't seen it yet ... And if you don't believe this story, check it out yourself: http://www.a1.nl/~ehofman/fgfs/gallery/santa/santa1.jpg http://www.a1.nl/~ehofman/fgfs/gallery/santa/santa2.jpg or grab the latest CVS version of FlightGear and take off in the UFO. Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
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). That sounds like a bug. My reading of the AI code indicates that motion should be continuous, no? I'm not sure where the problem is. I know very little about the graphics side of things. This would be a nice problem to solve, because formation flying is not possible yet. The AI airplane does move in discreet steps (once per sim tic) as does the user's view point, I assume. I guess they aren't drawn at the same tic? Also, we don't model downwash, wingtip vortices, weight change, and CG travel. Actually, weight change and CG travel due to fuel load *are* modelled. With YASim, at least, there is currently no way to get the new fuel state into the FDM (it wants to own the fuel load instead of reading it out of the property tree). But that's a really easy thing to fix if someone wants to work on this. That would be a good thing.I've been wondering how to let the receiver know that it is in position and can start downloading fuel. In the real world, the tanker has a box behind it which contains all possible positions of the fuel nozzle. If the position of the receiver's receptacle is within the box, then fueling can occur. Dave -- David Culp davidculp2[at]comcast.net ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
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
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
On Wed, 2003-12-24 at 05:51, David Megginson wrote: Cameron Moore wrote: One question though. I mentioned trying to line up with a fuel tanker and how the delayed movement was throwing me off. My guess is that this behavior was due to slow control surface movements. My question is if JSBSim simulates control surface movement speeds (excluding the flaps which do) or is the control surface deflection always exactly equal to the control input? Hinge moments for control surfaces probably have something to do with it, but remember also that you're flying a heavy, fast plane. Even if the plane is very responsive to control input (which has more to do with aerodynamic damping effects than control-surface response speed), you're not going to be able to change the flight path on a dime. All other things being equal, a plane that flies twice as fast (say, because of heavy wing-loading) needs twice as much time and four times as much space to make a change in its flight path -- that's why a little Cessna or Piper can start its landing flare over the runway itself, while a transport jet has to start flaring at least a half mile back (pulling up the nose at the last moment would only change the attitude in which the jet smashed into the runway). Airliners aren't that sluggish ... the flare is initiated below 50 ft AGL and that is definitely over the runway. Jet fighters turn fast only by pulling ridiculously high G-forces, and even then, they need a lot of time and space to turn around. I'm sure that inertia has a lot to do with it as well, but I don't know enough about physics to describe those effects. Inertia is a player, but most aircraft do not have large roll moments of inertia .. the mass tends to be concentrated close to the roll axis. All the best, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at DyessAFB
On Wed, 2003-12-24 at 08:01, Andy Ross wrote: Nick wrote: If the simulation is accurate the delays are due to the aircraft inertia and not control system delays. Hydraulic controls don't have a humanly discernable amount of delay. Simulators have their own delays too, the time it takes a signal to get through the circuit from the control to the computer and them to be processed in the next frame., but this is on the order of 50-100 milliseconds. Hydraulics *do* have a maximum slew rate, though, which might be what he meant. On a Cub, you can snap the stick from one side to the other and the ailerons actually move. With a hydraulic system, you can only move the stick so fast; the fluid in the pipes needs time to flow, and the pumps can only handle so much volume at once. Aircraft hydraulic systems are typically high pressure, low flow to minimize those sorts of problems. There is a transition-time attribute in YASim that you can use to specify speeds for surface deflections. I added it for flaps, obviously, but I think I've seen that Lee has used it for this kind of applicaiton. Andy ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
Tony Peden wrote: Airliners aren't that sluggish ... the flare is initiated below 50 ft AGL and that is definitely over the runway. I guess that brings us back to the old discussion about round-out vs. flare (U.S. books seem to distinguish the two). The jets are are nose-high and slowing about 1/2 mile back, whatever you want to call that, while the single-engine props are sometimes still nose-low at full approach speed when they cross the runway threshold. Inertia is a player, but most aircraft do not have large roll moments of inertia .. the mass tends to be concentrated close to the roll axis. I'm thinking of the effect of inertia on changing the flight path, not on changing the orientation. I obviously have no real-life experience, but I imagine that the hard part of an in-air refueling is getting the plane into the right place relative to the tanker and keeping it there, which involves modifying the plane's velocity and path of flight rather than simply its pitch and roll. I understand how velocity affects that (a plane twice as fast needs twice the time and four times the space to make the same change in direction with the same load factor), but I don't understand how inertia plays into it. All the best, and happy holidays to everyone, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] My Flight in a B-1B Flight Simulator at Dyess AFB
On Wed, 2003-12-24 at 17:53, David Megginson wrote: Tony Peden wrote: Airliners aren't that sluggish ... the flare is initiated below 50 ft AGL and that is definitely over the runway. I guess that brings us back to the old discussion about round-out vs. flare (U.S. books seem to distinguish the two). The jets are are nose-high and slowing about 1/2 mile back, whatever you want to call that, while the single-engine props are sometimes still nose-low at full approach speed when they cross the runway threshold. The nose up attitude is, I suspect, nothing more than a product of the angle of attack needed to fly at 1.3-1.4 times the stall speed. Procedures wise, though, once you are at landing flaps and trimmed on glideslope and final approach speed (which could be at the outer marker) the pilot would, on an ideal day, maintain speed and attitude all the way to the flare. Inertia is a player, but most aircraft do not have large roll moments of inertia .. the mass tends to be concentrated close to the roll axis. I'm thinking of the effect of inertia on changing the flight path, not on changing the orientation. I obviously have no real-life experience, but I imagine that the hard part of an in-air refueling is getting the plane into the right place relative to the tanker and keeping it there, which involves modifying the plane's velocity and path of flight rather than simply its pitch and roll. I understand how velocity affects that (a plane twice as fast needs twice the time and four times the space to make the same change in direction with the same load factor), but I don't understand how inertia plays into it. All the best, and happy holidays to everyone, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
