Flight dynamics problem in Engine not hardware???

[Guest Peter Sidoli]

>Not necessarily. Many aircraft have hydraulic flight controls, and the controls themselves only move actuators. Any "feel" is produced artificially with springs...and any change in required control loading force due to air loads is also artificially fed back by use of variable spring tension. That feel is a direct function of the flight control system design, with some secondary affect arising from flight dynamics as it interacts with the control system (in those acft equipeed with a variable Q mechanism in the artificial feel system). Capturing this is not deterministic solely w/r/t flight dynamics, and thus can't be modeled by a one-size-fits-all FDE engine

[Guest jimkeir]

Hi.If I'm reading this correctly it appears that two different issues are getting twisted together.I think what was originally being said was that the *input* requirements were unrealistic. To get a certain change in attitude a user should have to move his/her joystick by X amount when in normal flight conditions, but X*3 (or whatever) amount when moving slowly. Currently the FS engine doesn't seem to do that.Joystick calibration will have an effect of course, but only on the *absolute* distance required; a stick with a tiny amount of travel should still require 3x the movement, even if the actual amount of movement is much smaller than with a different stick with a huge amount of travel. In other words, calibration affects *absolute* movement, not *relative* movement.Force-feedback is an entirely different question - it's output, not input. As somebody pointed out, the fact that you may have to work harder to move the stick a certain distance is irrelevant to the result on the controls. If (heaven forbid) the feedback system in a real A320 which somebody suggested was done by springs were to fail, the aircraft would (should?) respond in exactly the same way for a given input; the difference would be that the pilot wouldn't *feel* the same thing.We really need to separate this because even though it's not usually realistic to assume no feedback whatsoever, most FS users probably don't have force-feedback sticks. Given this, isn't it reasonable to assume they're flying in the situation where a spring has twonged off into the cargo holds? Their *input* to the stick should do the same thing to the aircraft even if the aircraft - whether by cables, springs or whatever - can't do the same thing to the stick.Just my 2p-worth :)Cheers,Jim Keir

[oktorn777 0]

Very interesting thread. While we are at it, I wonder what sort of flight modelling full-size level D simulators use? And how much processing power they need to run? Do they base on a common software?And could those flight dynamics & weather engines replace those we got now in FS?Why should MS develope their own engines if there are very realistic ones out there in the airline industrie?There are 3 reasons, though, I can imagine this not to happen: processing power needed, money to buy it and the US goverment not wanting terrosist being able to buy a highly realistic sim for 50$.wondering,Claudio

[Guest Peter Sidoli]

>There are 3 reasons, though, I can imagine this not to happen: processing power needed, money to buy it and the US goverment not wanting terrosist being able to buy a highly realistic sim for 50$.wondering,Claudio http://forums.avsim.net/user_files/94324.jpg

[zfehr 1]

Peter,I'll second that. Maybe we should send the Microsoft team a copy of Richard Collins' DVD series on advanced weather flying. Now if they could get MSFS to emulate what he teaches on that set we'd have some fun, challenging, and at times surprising weather to deal with. That screenshot in your last post is close to the view angle ROTW included with their latest Seneca release. Wish I was flying instead of here behind the computer!Take care Peter,ZanePS Curious if you tried out the T37 mentioned in an earlier thread? I bought it as a result of that discussion and was quite impressed, would love to hear your impressions.

[Guest Peter Sidoli]

ZaneWeather in my opinion should be the flagship ingredient of the next version of MSFS.Microsoft have the visual candy down to a fine art now they need to add the meat to that candy.I would love to see downloadable weather systems as per real world with highs lows, fronts and their associated cloud formations, visibility, pressure chages,isobars, winds, turbulence, ice, temperatures. The list goes on :-)Then as I have outlined here variable control movement effect which is speed related and more control difference throughout the speed range.Nb the Seneca is going to be "work in progress" I believe ;-) superb work from all involved.Peter

[Guest jcomm]

Peter,I've been using PS1 (www.aerowinx.com) up to v1.3a, and I find Hardy's approach rather well thought. Not being ready to program any sort of FF into the core of PS1, Hardy decided to "translate" force into "course", thus requiring biger control deflections whenever increased force should be used in reality.This approach results in a very convincing experience, even for me who have already had the chance to fly a Level D sim.On the other hand, there are so many more superficial things about the way MSFS and other sims approach the simulation engine that make me doubt about it's usefulness for, say, IFR training. Take the simple "Turn & Slip Indicator" as an example:- When you fly the default or even the best add-on GA aircraft for MSFS, you generaly find the turn & slip 2 minute marks for standard rate turns. Try to measure the time it takes to complete a 360 degrees turn, or even a 180 degrees one if you don't want to wait for so long... Some will do it in 1' 40'', other in 2' 33'', etc... Very few if any will do it in anything close to 2'', wich is what it was supposed to be the result...

[Guest cw1011]

I think its an interesting topic. What I have to add is based on my time in the 777 simulator in Denver. I was quite surprised at the force required to flare, and hold the flare, that had been programmed into the fly-by-wire system that Boeing developed for the plane. You really had to pull hard to keep the nose up as the mains touched down. I have probably owned 10 joysticks, and only two give that physical, tactile sense. I have a PFC flight console (which I use for fs9)which includes one of their yokes (built into the console, not the jetliner stand-alone), and the Cougar HOTAS (for LOMAC and IL2) Despite some of the shortcomings in the Cougar (it's tendency to move easilly only in the cardinal directions and much harder when you try to both climb and turn), it's springs and resistance add a real element of realism to the programs I use it for. The PFC is also good, but I would like more even more resistance.I think the sim does a credible job modelling the differences at speeds. I have had many a landing where my trimming was not very good, and I have had to pull good and hard to keep the nose up. Same aircraft at high speeds, the plane moves with very small inputs. So, I think I am still in the "hardware is really important" camp on this. I am still really surprised that folks who are willing to plunk down $1,500 for the latest and greatest balk at spending anything more than $100 for controls.The single most important thing that has enhanced my enjoyment of the MSFS sim is the PFC control console. The heft, reasonably solid resistance, responsiveness and accuracy really help. And that is particularly true for the throttle quadrant, where you really can develop some muscle memory for throttle locations for certain settings.

[Avcomware 1]

Hi, Colin.>So, I think I am still in the "hardware is really important" camp on this.>I agree with that, but of all the controllers available to date, and I tried most of them, none do a credible job. This would imply that one thing that could help would be MS / the engine. I have a set of PFCs that I installed at the FBO, and we use them with PCATDs and I still cannot get a realistic feel. Interestingly enough, the are, and were, some sims that have a much better controller response / feel. As was mentioned earlier, the feel has to be implemented by the maker of the sim, since the engine is basically a calculator. This, feel, problem exists in some real life aircraft also, since many of the them are hydraulic and some fly by wire. The difference is that they have other interface, software / hardware combination that brings back that feel. Some are doing a better job than others. I know some people that would rather not fly than fly some of the

[AlaskanFlyboy 7]

It get's even more complex then that. Every aircraft has a different control yoke set up and linkage, Even in two similar aircraft, the controls can move considerable more or less then the other. Even then, I have noticed some people expect similar body frames to behave identically. I know there are several piper cherokee models out there of various varients. My real world experience is limited to just the "Cadet" and "Warrior III" varients of the Cherokees. While they look exactly the same on the inside with the exact same engines and nearly the same empty weights, the "Warrior IIIs" have a much more noticble nose heaviness at neutral trim than the "Cadets". Another thing is that there are forces in flight that a pilot instincively responds to as well. I fly the real aircraft much better then the $60,000 Frasca simulator we have and have noticed this with my fellow students at our flight school as well. The Frascas sim is a near-exact reporduction of the Piper Warrior III and I know I'm moving the yoke the same, but I still have trouble maintaining stable flight. The hyper-sensitive instruments in the human body affect us in ways we don't even understand (just look at spacial disorientation incidents; no matter how hard you train for it, it still hits you).I know in the sims (MSFS and the FAA certified Frasca) that I have a tendancy to over control. I feel that this is simply from the lack of sensation in my butt that tells me I'm pulling or pushing or banking too quickly. Your body is more of a guage of how quickly you're imputing controls than the gauges are. The gauges really don't tell you how fast your imputting them. When you're looking at the gauge, you're looking to see where you want it stopped, you really don't pay much attention to how fast the needles moving there unless it's noticibly excessive. However, even the smallest movement that looks negligible on the gauges is felt quite well.I invite anyone to take up the Be A Pilot offer and get an introductory flight from a local flight school that accepts Be A Pilot certificates. You may be amazed at the sensations you feel flying the plane for real.----------------------------------------------------------------John S. MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private 130+ hrs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

[maxter 0]

Hi Peter,One person who is superbly qualified to speak on this topic is Steve Small of FSD International. What he dosn't know on the topic, I venture would not really be worth knowing.He has had some interesting things to say about various components of the MSFS simulator engine in the past. Maybe Steve would like to comment on this thread. It would be really interesting.Chris Porter:-outtaPerthWestern AustraliaMy "Around the World 4" flight pagehttp://members.iinet.net.au/~portercbp/fly...e%20World_5.htm

[Guest]

Another factor is that the responsiveness of control hardware in FS is a lot lighter than in a real aircraft (possibly discounting Airbusses with their completely decoupled sidesticks).A 10 pound force on a CH yoke will give a lot different control input compared to a 10 pound force on a yoke in a C172 and the yoke in a 737-800 will react differently again.That's a main reason real pilots have difficulty handling FS, applying the same force will cause completely different control deflection (and therefore aircraft behaviour).The correctness of the flight dynamics engine should be tested using only control deflection and the resulting aircraft reaction to that deflection.And even then you can only blame the engine if you know it is getting the correct data from the FDE which itself controls the engine.