I've been using Flightgear for a few weeks now, and I must say it is an excellent program. However, I have some queries:1. Whenever I accelerate any plane down the runway, it will start to veer to the left. I compensated for this by moving the rudder so the plane turns right, but when I reset the rudder position the plane starts veering again. I have already ensured all my controls are centralised before take off.2. Sometimes when I am in the air, the plane will start to pitch and dive for no apparent reason, especially to the left. Is this connected with the previous problem?3. Sometimes when I am flying the Cessna 172, I start up the engine with the spacebar but after I release it, the propeller stops spinning again, but at other times this does not happen.4. Finally, I would like to know what the option "Model Hertz:" and "Speed:" in the Advanced Options window change.

>I've been using Flightgear for a few weeks now, and I must>say it is an excellent program. However, I have some queries:>>1. Whenever I accelerate any plane down the runway, it will>start to veer to the left. I compensated for this by moving>the rudder so the plane turns right, but when I reset the>rudder position the plane starts veering again. I have already>ensured all my controls are centralised before take off.What are your weather settings?Have you verified whether the problem remains the same if you simply disable all winds (disable metar!)?Also, does the problem appear to be specific to certain aircraft/FDMs?JSBSim aircraft are somewhat famous for this tendency.>2. Sometimes when I am in the air, the plane will start to>pitch and dive for no apparent reason, especially to the left.>Is this connected with the previous problem?how exactly did you ensure that all your controls are "centralized"?If you enable the hud while your controls are in neutral position, does the hud display neutral positions, too?>3. Sometimes when I am flying the Cessna 172, I start up the>engine with the spacebar but after I release it, the propeller>stops spinning again, but at other times this does not>happen.sounds as if it's supposed to model a realistic engine? >4. Finally, I would like to know what the option "Model>Hertz:" and "Speed:" in the Advanced Options window change.a) this is the interval at which the flight dynamics model is run:( not sure to which "advanced options" you are referring (fgrun?), but it's probably meant to refer to the simulation time, i.e. 1.0 is the default (real time) and you can increase/decrease the simulation time by modifying this value-either setting it directly, or using the a/A switches.

> 1. Whenever I accelerate any plane down the runway, it will> start to veer to the left. I compensated for this by moving> the rudder (...)Good boy/girl! :-)FlightGear is a simulator. It tries its best to do what the real aircraft would do. Read more on that here:http://www.mindspring.com/~cramskill/propefct.htmWind may add to that effect.> 2. Sometimes when I am in the air, the plane will start to> pitch and dive for no apparent reason, especially to the left.> Is this connected with the previous problem?Happens if you don't have enough airspeed (-> stall).> 3. Sometimes when I am flying the Cessna 172, I start up the> engine with the spacebar but after I release it, the propeller> stops spinning again, but at other times this does not> happen.It happens if the magneto switch is turned off, which is the case after resetting fgfs (e.g. after an aircrash). Press the right-bracket key 3 times to switch it on, then press the space bar (There may be other reasons, too, but those are unlikely in your case. :-)

Thanks for the help, but regarding the answer to the second question, what kind of speed do I need to prevent stalling and in what position should the throttle be (25%, 50%, 100%?) during flight?Also, I notice the first problem with jet aircraft with engines nowhere near the rudder too, such as the 737. Is there a reason for this?I also have some new questions:Why does the plane stall when autopilot is turned on? (I also need to know exactly what the stuff in the autopilot settings do)Why doesn't Ctrl+T (follow terrain) work? If I'm not wrong, it worked once with an A-10, but I am not able to replicate that.Also, Ctrl+U is supposed to increase altitude by 1000 ft, but when I press it my plane suddenly jumps to 5 metres above ground level.When I fly the F-16, immediately after it leaves the runway, it will suddenly loop the loop twice and crash. Why does it exihibit this behaviour?One last question: How in the world do I keep the Wright Flyer in the air for longer than 3 seconds?!

>Thanks for the help, but regarding the answer to the second>question, what kind of speed do I need to prevent stalling and>in what position should the throttle be (25%, 50%, 100%?)>during flight?In general, you cannot easily answer such questions as the answers depend heavily on various factors such as aircraft,altitude(density),attitude,engine power,weather (temperature),configuration (flaps/gear), so these numbers are very specific to individual aircraft.Apart from that you need to realize that not all aircraft in FlightGear can be considered to be fully functional or even realistic. So, you should concentrate on using those aircraft that are supposed and known to work for most flight regimes.So,the default aircraft (c172p) should be quite flyable, thus I would recommend to simply use what's supposed to work.>Also, I notice the first problem with jet aircraft with>engines nowhere near the rudder too, such as the 737. Is there>a reason for this?You still didn't provide us with data that I asked you for, as I suggested already this may be FDM specific, the pre-2.0 Jsbsim aircraft where quite prone to weather related effects. So, I would verify if the problem remains the same if you simply disable all winds.>I also have some new questions:>Why does the plane stall when autopilot is turned on?depends again on various things, most likely this stall is due to too low airspeed or simply too much pitch. Without knowing anything about the aircraft and autopilot settings you are using, it's hard to tell you what exactly is the cause for your specific problem. (I also need to know exactly what the stuff in the autopilot settings do)actually it's pretty self-explanatory: 1) control lateral mode (roll), 2) control airspeed, 3) control vertical mode (altitude).>Why doesn't Ctrl+T (follow terrain) work? If I'm not wrong, it>worked once with an A-10, but I am not able to replicate>that.you will have to be more specific: which aircraft are you referring to now?>Also, Ctrl+U is supposed to increase altitude by 1000 ft, but>when I press it my plane suddenly jumps to 5 metres above>ground level.>When I fly the F-16, immediately after it leaves the runway,>it will suddenly loop the loop twice and crash. Why does it>exihibit this behaviour?http://www.seedwiki.com/wiki/flight_gear/h...cfm?wpid=247004>One last question: How in the world do I keep the Wright Flyer>in the air for longer than 3 seconds?!1) increase to maximum thrust2) maintain a low AoA3) fly or simply use the autopilot ;-)However, in general many of your questions are pretty broad and the corresponding answers are not necessarily specific to FlightGear, I would recommend to check some documentation about flying flight simulators, so that you get a basic understanding of what you need to do in order to keep the simulated airplane in the air:http://stoenworks.com/How%20to%20Fly%20Flight%20Sims.htmlhttp://stoenworks.com/Tutorials/How%20to%2...0airplanes.htmlhttp://stoenworks.com/VFR%20flight.htmlhttp://stoenworks.com/Tutorials/Throttles%...ures%20and.htmlhttp://stoenworks.com/Tutorials/Cowl%20Fla...Engine%20C.htmlhttp://stoenworks.com/Tutorials/Understand...20airspeed.htmlhttp://stoenworks.com/The%20Power%20Curve.htmlhttp://www.4p8.com/eric.brasseur/flight_si...r_tutorial.htmlhttp://www.av8n.com/how/This should get you started.Many other more advanced tutorials are available at:http://stoenworks.com/Aviation%20home%20page.html

Ok, I'm not sure about the FDM version, but I'm using FG 0.9.9. Regarding the terrain follow, I'm experiencing the problem for most of the planes I've flown so far (such as the Cessna 172, Boeing 737, YF-23, etc.), and as for the wind speed, I've already turned wind off.And I also seem to be experiencing problems turning the planes. For example, when I turn the 737 right, it will start pitching and diving dangerously. When I do the same to the YF-23, it pitches to the left and starts to stall. If I turn in small increments, nothing seems to happen at all. Also, whenever I climb, I will start to lose airspeed drastically after some time, regardless of the angle of incline of the elevator, and so far I have not managed to land any plane and keep it on the ground a single time; either it crashes (gets stuck) or bounces into the air again. How do I prevent the above two from happening?Finally, I would like to know, what would happen if I fly into an area that I do not have scenery for?

>Ok, I'm not sure about the FDM version, but I'm using FG>0.9.9. Regarding the terrain follow, I'm experiencing the>problem for most of the planes I've flown so far (such as the>Cessna 172, Boeing 737, YF-23, etc.), and as for the wind>speed, I've already turned wind off.Are using any sort of input hardware (joystick,yoke,pedals)?If so: are you sure that your controls are in a centered/neutral position?>And I also seem to be experiencing problems turning the>planes. For example, when I turn the 737 right, it will start>pitching and diving dangerously. When I do the same to the>YF-23, it pitches to the left and starts to stall. If I turn>in small increments, nothing seems to happen at all.How exactly do you control FlightGear (keyboard,mouse,joystick/yoke), is this a general problem, or does it also occur if you switch control mode?And what's the value of your /sim/model-hz property?Have you tried adjusting this value to your hardware?Also, does the same problem occur if you use the autopilot to control the aircraft?>Also,whenever I climb, I will start to lose airspeed drastically>after some time,regardless of the angle of incline of the elevator, in general, climbing usually entails an decrease in airspeed, so you have to compensate for this by increasing thrust. However, if you slow down ridiculously (i.e. stall?), you will want to verify that you are using a proper AoA and configuration (flaps, gear). Likewise, the weather settings may also influence the aircraft's peformance.Apart from that I am not sure if you are familiar with the fact that IAS (indicated airspeed) necessarily decreases at altitude, even though your TAS (true airspeed) and ground speed may be totally sufficient. >and so far I have not managed to land any plane and>keep it on the ground a single time; either it crashes (gets>stuck) or bounces into the air again. How do I prevent the>above two from happening?So, there are many things that need to be taken into account. Without knowing any details (aircraft, weather settings (temperature!), configuration, altitude, airspeed etc.) it is hard to determine if the behaviour you are seeing is indeed a "bug" or indeed realistic.Besides, not all FlightGear aircraft can currently be considered to be functional, some have a pretty basic FDM that will only work properly within a certain flight envelope.The citation is a good example for this: it's an excellent model and features an awesome 3D cockpit, however its FDM is barely flyable-unfortunately. These are the cases where you may indeed benefit from FlightGear's open architecture, providing you the possibility to simply refine or even replace any aircraft's FDM in order to improve it.>Finally, I would like to know, what would happen if I fly into>an area that I do not have scenery for?try it: you won't see any terrain/scenery, so the only thing you'll get is ocean, however the navaids remain working. So you could still conduct IFR flying.