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Virtualwombat

FSX Cessna 172 vs RealAir FS9 Cessna 172-flight???

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Does anyone have an opinion as to how correct the flight dynamics of the stock FSX 172 are? In FS9 the RealAir 172 was the objective standard for many. Despite all of the visual, WX, and ATC stuff that enhances FSX it is difficult to use the program if the primary underlying vehicle simulation is not the best possible. Since I am not a pilot (only drove/flew a 172 once) I must rely on the comparative opinions of others.Regards,Dick Boley

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Dick, Give your question a shot in the FS-X forums. Somehow it ended up in Hangar Chat. You'll get more answers there.-John

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I've seen mixed opinions about this, I've only just started flying a real 172 - I would say the FSX one is pretty accurate - I certainly felt at home moving to the real thing and it pretty much does the same stuff. I'm not sure I really understand realism in flight models - is it very subjective? One thing most of us don't have in our computer simulator is the seat of the pants feel or the correct control pressures - so how subjective does that leave the realism of the flight models?If you point the FSX 172 up at the right angle on full power it climbs at 80 knots indicated, as does the prototype, point it down with constant power the airspeed increases. Yaw it to the right with just rudder and after a bit it banks to the right too..as it is supposed to. I guess a lot of this is to do with immersion, how realistic does the model look from inside and out as well as the general feel and how all this comes together to make a model realistic? I guess where you will see limitations in the FSX model is at the edge of the flight envelope, but generally it does the same as the real plane in 'normal' flight.Wonder what others think! My wanderings are not really an answer so much as an extension of your question :0)Best regards,Gemma

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Not very. I've just completed a comprehensive flight dynamics test comparing FSX vs X-Plane vs RealAir.There are problems with all 3, but FSX and X-Plane fail especially when it comes to rudder control. The RealAir handles rudder a lot better, but is by no means perfect. I get the feeling the FSX 172 doesn't behave much different than the FS2000 one to be honest.I hope my site goes live in April and then you'll be able to read all about it :)Cheers,Christian

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>There are problems with all 3, but FSX and X-Plane fail>especially when it comes to rudder control. The RealAir>handles rudder a lot better, but is by no means perfect. I get>the feeling the FSX 172 doesn't behave much different than the>FS2000 one to be honest.>It was my opinion that the FS2004 Cessna 172 had made enough progress, that I didn't bother with the RealAir update anymore. For the best in slips and spins, I just went with the RealAir SF260, since I don't consider the 172 to be a serious slip & spin machine anyway, let alone aerobatics where rudder is of great use.The FSX 172, will slip, but not as well as the RealAir version did. But it does have enough cross-control for some decent crosswind landings, where the up-wind wheel touches first.The model also requires some left rudder for the takeoff roll & climbeout which is good. As to the amount and simulated "feel" of rudder required, I believe that the FS2000/FS2002 models were better.They lost a bit when MS changed some of the "ground roll" dynamics in FS9. However, aircraft such as the RealAir Spitfire, seem to have programmed around this "reduced feature".Start a turn with aileron & "step" on the ball at the same time for a coordinated turn (example: left aileron & left rudder). Once established in the banking turn, neutralize aileron, get rid of the adverse yaw, and the ball usually re-centers. This is again "good", and along the lines of what you should expect.All in all, just as with FS9's version of the Cessna172; I feel that the model does a very capable job of getting from point A to B, with normal pilot imputs, and a power/speed range that I'd expect. For spin practice...........use something else! :)Tried the FSX Caravan? For a "default model", it's really quite good in both looks, the VC, & the feel of flight. Certainly as good as some payware!L.Adamson

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Again, due to my current real life flight training- I've found none of the models are necessarily "realistic" in terms of feel. They hold the numbers pretty well, but there is a serious problem with pitch stability in flight simulator. X-Plane is bad in that aspect too. I can assure you in real life trimming and maintaining altitude is relatively easy.Personally, I think turning the "realism" settings down a notch are more realistic. You shouldn't have to think about flying the airplane- in FS, you really have to fixate on it, which doesn't leave much time for every else.And I definately agree, the rudder stinks in the default plane. The 172 is not meant to slip with flaps down in real life- the manufacturer has decided there may be undesirable handling characteristics. My brother's flight instructor has done it, and said it's not a big deal- but he did say he didn't recommend it for a low hour pilot.

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Well, yea, in real life trimming and rudder control is a lot easier, because you can actually feel the forces and the resistance on the yoke and on your body.I can trim a C172 in no time in real life and correct the rudder in a turn without "chasing the ball", but I simply cannot trim correctly to save my life in any flightsim regardless of the aircraft, because I just don't feel the forces. That's just one of the shortcomings of a simulation, I guess.Pat

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That is an interesting observation Pat. I have a saved flight with the FSX 172 with it trimmed just right for straight and level flight. This was probably more luck than design but when starting with this flight using visual cues to fly the plane I have only to put in tiny inputs with my yoke, much like my real life experience. This suggests to me it is not so much a case that ther pitch stability is not modelled well but much more a case that it is difficult to trim correctly in the sim with no feedback of control forces. Certainly one of the not so obvious issues with FSX and pitch stability are the mad thermals, I did notice that switching them off helps a bit with maintaining desired altitudes!With this particular saved flight I can for example alter the pitch without changing trim to see the change in airspeed and then 'hands off' the FSX 172 will stabilise in pitch and find the original airspeed without any trouble. This suggests that stability in pitch is modelled well and again like the prototype, but that perhaps finding the correct trim with no feedback is difficult to achieve.Interesting about rudder observations, how are you guys testing the model? i.e. is the input device (pedals)standardised or are you looking at the actual deflections of the control sufaces? Be really interested to know as I have some knowledge of flight dynamics, but not as applied to computer flight sims.

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>Interesting about rudder observations, how are you guys>testing the model? i.e. is the input device>(pedals)standardised or are you looking at the actual>deflections of the control sufaces? Be really interested to>know as I have some knowledge of flight dynamics, but not as>applied to computer flight sims.As to rudder; it's a case of what part of the flight envelope we're talking about, rather than just saying it "stinks" as a broad term that appears to apply to everything. :D First off, IMO, there is no point in really chaseing a simulated ball, because real planes vary anyway. I fly a (non simulated)plane that uses frize ailerons, and has very little adverse yaw. It's basically feet on the floor for turns. As to the simulation, know what the rudder's purpose is, and then kick in a bit if you have rudder pedals. I'd just as soon use auto-rudder than bother with a "twist grip". Personally, I use the pedals all the time for the takeoff roll & climb; as well as cross wind landings, aerobatics, and small heading adjustments to the runway.And FWIW, generally the FSX models that I've tried, are a bit easier in trimming than previous versions. I don't even attempt to hold exact altitudes within +/- 50' when using desktop flight simulators. The horizon is to small on my monitor to "want" to do it visually, and it's rather annoying to even try. It's either auto-pilot for any real distance of level flight, or just not bothering! :-hah L.Adamson

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We're definitely pushing the limits of simulating to fly a plane.One could argue that the amount of travel of a flightsim yoke is much less than on a real C172. All input devices can be calibrated and the sensitivity can be adjusted. I have found that the standard FSX settings for the CH yoke and pedals are inaccurate at best.I had been flightsimming since FS 5.1, when I took my first flying lesson a few years ago and I have found it to be exponentially easier to fly a real plane, especially when it comes to managing the flight controls.The techniques, for example, for trimming are substantially different. In a real plane, you feel the pressure ease on the yoke when you trim. In a simulation, you pretty much look at your VSI. The same applies to the rudder controls: Apply too little and you feel yourself being pushed to the side and you almost instinctively apply enugh rudder to compensate for adverse yaw.I am not sure how one can argue that flight dynamics for flight inputs are incorrect. They are incorrect to begin with, if you take the travel distance and the lack of "force feedback" of the simming controls compared to the real deal.However, it's an interesting topic.Pat

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This was my experience also regarding flying a real plane. On my first flight my instructor knew I had previous FS experience and we discussed the usual fault of looking down at the instruments all the time before the flight. After taking control it was one of my first comments to say, "this is a lot easier than flying a computer simulator", it just is as there is feedback all the time. Compare a computer based driving game to taking a drive in a real vehicle.The differences in the input devices is what interests me, how can it be said that a rudder doesn't work like the real thing if the inputs are not the same in the first place and also depend in the real world on power settings, attitude, airspeed etc. Is any of this actually accounted for?I've recently been reading the Bruce Williams book on using MS flight sim as training aid.. what becomes clear is that using computer flight sims to learn 'control inputs' is not a good idea, mainly because however it is modelled it will be 'wrong' as there is no feedback. Flying using the 'numbers', visual flying and working through procedures is very good though.Certainly realising this has helped me a lot. It doesn't mean that FSX Cessna 172 model is useless in the sense of the OP, far from it, it was quite an experience to fly the 'real' circuit unaided on my first real world training flight simply because I knew it back to front from flying it in FSX with Just Flight photo scenery (there is the barn, there is the wood, there is the square wood, there are the ponds... that was amazing!).This goes back to my original comment, I believe the flight model is reasonably accurate of the Cessna 172 in FSX - however the control inputs are not because of the various control devices we connect to our machines and the total lack of genuine feedback that they produce.So maybe we have an answer for the OP, no PC simulation currently accurately models flight control inputs - but it doesn't make the experience any less worthwhile as long as you are aware that the control inputs are not 'exactly' like those you would use in the real plane.One funny observation I have is that an hour in a 172 certainly makes me fly better in FSX!

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This has been a most interesting set of inputs. It seems that there are no gross issues with the flight model, as in some previous evolutions. The simulated aircraft does react well given the obvious limitations of the program and the wide variations in knowledge and hardware. Therefore, with the simulation working well, the next level of interest is the lack of physical feedback on a "whole body" basis. This has been mentioned before but it seems to have risen to the primary "I would like to have" level now that the program does a decent job of simulating flight - ack caveats.Building the 3-axis simulator in the basement is the next step. Vibrating chairs and tracking glasses are ok but that "whole body" feeling is awaiting the $500 solution! Challenge fo the addon people.My personal objective is satisfied. That is, I have a reasonable level of confidence that the product does simulate flight in a rational, or better, manner. Can there be improvements? Undoubtedly, but what we may have reached a plateau. A plateau that was preceded by a steep climb from crude to sophisticated.Regards,Dick Boley

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I am sure that we'll see a lot of technical innovations in the years to come.TrackIR was one of the more significant one, as far as I am concerned. I am sure the future will bring even more realism with seating rumble pads, hydraulic chairs, bigger screens and hopefully some better input controls.It is really somewhat sad that there seems to be only one manufacturer for flightsim yokes. I am not a fan of the CH Products at all, but they seem to have had a monopoly on yokes for almost a decade. The flightsim yoke hasn't been updated in how many years now?Pat

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I don't want to sound too much of a 'know it all' but there is much hidden in FSX (and probably FS9) that adds to the realism with what we have now. Not so much whether control inputs are perfect or flight dynamics perfect, or how the sensations of flight could be reproduced, which I think will be developed on in the future, but also how the sim is used. I bought FSX as a cheap way to get some experience, fix some theory in my thick head and generally to have some fun before doing it all for real - with the Just Flight UK photo scenery to help me out, I can even hopefully not get too lost on my training flights.You may know about this already, but from your OP you may find the following useful. I found for example in the 'real world' an instructor will want the student looking outside of the cockpit 90% of the time. Can you do this in the default FSX 172? #### yes! Use the virtual cockpit, adjust the seat so you can see some of the nose cowl and move your eye point out as it would be in the real A/C and try maintaining 2,000 ft for 15 minutes by keeping the gap between the top of the instrument shroud and the horizon constant - only checking the instruments for a second or two occasionally. I was surprised how much easier it is to maintain altitude like this in the sim rather than try and fly it at a constant 2,000 ft on instruments - this is just what I did in the real A/C when flying VFR and it adds so much to my FSX sessions now to do the same. I do this whilst flying around my local patch in FSX taking in all the major land marks. (Much cheaper than Avgas and nearly as much fun). My trick is to have the instruments just out of sight in my default forward view. I watch the horizon and keep my loookout, then to check the instruments I have to use my 'top hat' switch to look down. This makes me think 'OK quick check, then eyes outside before the 'instructor' spots that I'm gazing at the instruments'. I then have the default view on a button on my yoke so I can be eyes outside before my imaginary instructor can notice (my real instructor always notices). At the same time I concentrate on my flight attitude using outside visual cues and spotting all those important landmarks that may 'get me home' for real one of these days).Sorry if you know all this but for me the realism increased significantly once I had this set up right. I have some comparison pics from my first training flight and FSX screen shots, as real as gets? Yes, it is nearly there :0)If you are interested in this sort of stuff PC Pilot had a good article called 'Back to Basics' in #45 that covered this kind of thing and the Bruce Williams book will bring a lot to anyone wanting to improve their use of flight sims in general for GA aircraft, particularly the reinforcement that things are being done 'right' from the start and how to interpret the real and the simulated experiences.

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As I noted in another post, I recently converted the FSX C172 to the FS9 Realair version by replacing the .air file with the Realair version and then using a program called Winmerge to compare the two aircraft.cfg files to do a diff on the files and move over the relevant portions from the FSX version to the RA version.For the most part the FSX version seemed ok, until I tried do some stalls. The FSX C172 would keep flipping to the left and down on me at stall very quickly, and control was completely lost, something I never found stalling the Cessnas I've flown. When I upgraded (downgraded?) it to the RA files, the stalls settled out. The power-off stalls still don't feel quite right, but they are a lot closer, I'm able to keep the wings level and the plane just mushes in. And power-on stalls seem to act much more realistically. I'm able to sit there with the plane trying to rotate in the horizontal plane about the CG, being rather difficult to maintain a particular heading. And, while difficult, I am able to keep the wings level for the most part, just like I remember. So this version stalls about like I remember in the Cessna's I have flown.Not perfect, but much better.I, too, would like to hear other people's opinions.BTW, I'm sorry, the license on the RA download specifically prohibits redistribution of any of the files in the package, so I can't upload my version of the .cfg file without Rob's permission. But it's really not difficult to do yourself. I just added a few missing lines to the RA version and adjusted a couple of things here and there. Check out Winmerge, it makes the job very easy.Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

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