Geofa: I think you missed my last post.. :) And from what I've heard through the grape vine, PMDG doesn't even use the built in flight model anymore for FSX. Just to be clear If I had to choose between PMDG/LDS or Xplane 9, I'd drop XP9 in an instant. However you ask me to build you a simulator or a new plane, X-plane is where I'd start!

Geofa: I think you missed my last post.. :) And from what I've heard through the grape vine, PMDG doesn't even use the built in flight model anymore for FSX. Just to be clear If I had to choose between PMDG/LDS or Xplane 9, I'd drop XP9 in an instant. However you ask me to build you a simulator or a new plane, X-plane is where I'd start!

I just talked to a developer who uses esp-there is no blade element theory in esp and it is not required for certification.

Now with more development X-plane should be able to implement the full bus used in all civil/military aircraft.. then Boeing doesn't have to rely on anyone else to develop a full flight sim... just build the cockpit connect it to X-plane and you've saved a few million dollars :)

And that's the long shot....More development could take years; because right now................. blade element theory , isn't all that powerful. The Van's RVs that are included with XP9 don't fly much like the real ones; and I'm certain they were created through plane maker using blade element theory. The speeds are way off, and they balloon upwards with flap deployment, rather than pitch down. I wasn't thrilled at all, by flying them, and immediately went back to the Real Air SF260 for FSX which is far closer to the actual SF260 which I've flown, as well as the RV's. At this point, I certainly wouldn't trust X-Plane in deciding if this is the way a new design will fly.BTW---- I brought up this before, and the creator of the MU-2 for X-Plane has been working on a re-vamped RV.L.Adamson

Well you have to remember one thing... the Blade Element Theory is only there to replace the engine performance data when you can't get it from a reliable source which is the case 99.999% of the time. Now if the aircraft manufacturer works with the developer and hands over all that proprietary data as in the case for PMDG, then hands down it's going to be more accurate. Afterall it is a look up table + interpolation in the real FMC/VNAV as well... They simply attach sensors to the real plane and grab that information during test flights then populate the data fields for the flight computers.You can't do that with FSX since the data has to come before the first flight and that data is going to determine the performance regardless if it's accurate or not. It's kind of a chicken and egg thing... And X-plane is a little more akin to how things are done in the real world, where you aren't suppose to know the performance until you build it :)

Well you have to remember one thing... the Blade Element Theory is only there to replace the engine performance data when you can't get it from a reliable source which is the case 99.999% of the time. Now if the aircraft manufacturer works with the developer and hands over all that proprietary data as in the case for PMDG, then hands down it's going to be more accurate. Afterall it is a look up table + interpolation in the real FMC/VNAV as well... They simply attach sensors to the real plane and grab that information during test flights then populate the data fields for the flight computers.You can't do that with FSX since the data has to come before the first flight and that data is going to determine the performance regardless if it's accurate or not. It's kind of a chicken and egg thing... And X-plane is a little more akin to how things are done in the real world, where you aren't suppose to know the performance until you build it :)

You can get reliable engine performance data from the POH for most aircraft 99.990% of the time-the .001 % difference would be differences due to age of the engines, rigging.There are some things I like about Xplane's "Blade Element Theory". The illusion of in flight feeling (dutch roll, turbulence etc.) is much more believable than fsx. However, controlling the plane with expected performance and numbers is much more close on fsx-I haven't found a plane yet on xplane that flies like the real aircraft I have flown-I have found many in fsx. I can rarely land or make a good takeoff in Xplane due to oversensitivity in the axes's. Doesn't mean it can't be done...I am waiting. For practicing instrument procedures being able to fly the numbers is very important for training.

Honestly thıs ıs why I hate FSX... everythıng ıs fıne for the most part on takeoff climb and cruise... pretty close to the real thing... however when I'm landing and doing an ILS intercept I find it unnatural to have the plane pitch up to 10 degrees to intercept... I've been in countless aircraft NONE of them do this in the real world... yet this is the case for just about every FSX aircraft out there including the PMDG's and LDS...And thats where we need to depart from Blade element theory.. and realize there are about 100 extra things modelling the physics in X-plane... the wings and flaps are accurately done... the plane is suppose to pitch back during flap deployment and you are suppose to counter act that with trim... again not the case in FSX you can drop flaps from 0 to 45 degrees and never trim once.Another problem with FSX.... you end up pitching the nose down to track the glidescope... where as in the real world you use throttle. Despite what the tutorials say in FSX it isn't the case. Another thing... in FSX I can't get the plane to hold any speed properly, In x-plane I don't even need to look at the IAS... I know what speed I'm at because it doesn't fluctuate...should i go on... bottom line I'll wrap it up as this.. Blade Element Theory is for the engines... and replaces the performance/mach tables in FSX... Where as the Flight model ends there in FSX... in x-plane that's just the beginning.... heck you can even have ice build up on the wings, proper wing flex... and guess what instead of modelling a singular point... X-plane models 100's of point on the aircraft, in fact each section of the wing is independent of the next...I mean we're comparing apples to an entire fruit salad :) Things may not be perfect in X-plane after all Garbage in Garbage Out right.... but I find it impressive that someone including myself can mock up an entire airplane in a weekend, and guess what plane maker is free. And if it was true that accurate engine performance data was as freely available there would be a lot more CATIII capable FSX aircraft out there... the truth is the performance data is ussually imagined and simply bogus.. And if you still think 10 degrees nose up at 180knots with 5 degree flaps during intercept is normal then you really need to fly another airline....

"Another problem with FSX.... you end up pitching the nose down to track the glidescope... where as in the real world you use throttle."I use throttle fine with fsx-and each 1" of manifold or rpm does equate to +-100 fpm-dropping the landing gear does cause a 500 per minute descent. I can fly the default Baron or any of the 3rd party great fs add ins by the same numbers I use in my plane and get extremely close to book values-both in airspeeds, performance, and expected results.Xplane is twitchy, especially in the pitch access despite adjusting all joystick parameters, and fm settings. I'm lucky if I can just maintain altitude within +-200 ft. It seems to love to go into ever increasing oscillations -especially on takeoff but sometimes even in the air a little rudder input can make the aircraft quickly uncontrollable . It just lacks stability and momentum. There are three things I really like from xplane though. The general feel of the aircraft and effects in cruise, the ability to adjust and sych multi's by sound, and the systems failures. I do wish fsx had these features-but when you take an aircraft like Real Air's Duke or Carenado's Seneca, or Just Flight's Duchess-there is just no compare-and I spent months doing my own aircraft in Xplane hoping to get something better and useful to me. At least with Reality Xp's Garmin for Xplane there is finally a real working avionic-I am glad for that. Perhaps when a quantity of aircraft that duplicate what is available and taken for granted in fsx appear in Xplane it will hold its own. Perhaps even the fm is superior-but one really needs to see it in action, not theory to believe this.

At a certaın level I want developers to come over to x-plane especıaly Carenado and even the Reality XP stuff looks promisiong, and at another level unless they want to contribute to the open source atmosphere they shouldn't bother. As a programmer there are bigger issues I feel are often neglected in FSX... such as the use of GDI+ versus OpenGl/DirectX. Sure it's easier to program but it comes at a serious cost in overhead when there really is no CPU to spare at all. Take for example the PMDG MD11X versus the PMDG 747X.. both relatively have the same complexity in their visual model, but you get 2x-3x the frames in the MD11 versus the 747. And from what others have been saying it's not just the usual overhead thats an issue the two (gdi+ and directx) just don't seem to get along much like the Aero theme and Vista. Obviously this is not an issue in X-plane because you're forced to use OpenGL and C++ only, especially if you want cross platform compatibility. And to be honest I've learned more practical things about FSX programming from the PMDG forums than from reading any blog from the Aces team. Most people assume that FSX has issues with CPU... not the case.. the real issue has always been Microsoft and their extensibility approach in any language under the Microsoft umbrella will do. Do you really need the cabability to send emails inside the guage acode and for it to be written in the slower .NET language like VB? These are serious marketting issues that ruined FSX.. and why I believe it's always been a tad bit "broken" in comparison to FS2004. Sure it may increase the overall number of addon developers but they ended up merging the OS with the game itself.Having said all that any developer that has bad things to say about X-plane SDK can seriously shoot themselves, as I probably would never buy their products anyways. The people I buy my FSX stuff from should know I'm willing to fork out another 60-80 dollars for an x-plane version...

And thats where we need to depart from Blade element theory.. and realize there are about 100 extra things modelling the physics in X-plane... the wings and flaps are accurately done... the plane is suppose to pitch back during flap deployment and you are suppose to counter act that with trim... again not the case in FSX you can drop flaps from 0 to 45 degrees and never trim once.

Hmmmm......It seems that most FSX aicraft that I've flown................... do balloon upwards with flap deployment if they're suppose to. But keep in mind, that some aircraft remain rather neutral, or pitch nose down as well. As I previously stated, RV's pitch nose down with flaps, but the X-Plane model RV's pitch up. Something is wrong, wouldn't you say...L.Adamson

"Another problem with FSX.... you end up pitching the nose down to track the glidescope... where as in the real world you use throttle."I use throttle fine with fsx-and each 1" of manifold or rpm does equate to +-100 fpm-dropping the landing gear does cause a 500 per minute descent. I can fly the default Baron or any of the 3rd party great fs add ins by the same numbers I use in my plane and get extremely close to book values-both in airspeeds, performance, and expected results.Xplane is twitchy, especially in the pitch access despite adjusting all joystick parameters, and fm settings. I'm lucky if I can just maintain altitude within +-200 ft. It seems to love to go into ever increasing oscillations -especially on takeoff but sometimes even in the air a little rudder input can make the aircraft quickly uncontrollable . It just lacks stability and momentum. There are three things I really like from xplane though. The general feel of the aircraft and effects in cruise, the ability to adjust and sych multi's by sound, and the systems failures. I do wish fsx had these features-but when you take an aircraft like Real Air's Duke or Carenado's Seneca, or Just Flight's Duchess-there is just no compare-and I spent months doing my own aircraft in Xplane hoping to get something better and useful to me. At least with Reality Xp's Garmin for Xplane there is finally a real working avionic-I am glad for that. Perhaps when a quantity of aircraft that duplicate what is available and taken for granted in fsx appear in Xplane it will hold its own. Perhaps even the fm is superior-but one really needs to see it in action, not theory to believe this.

I see many testimonials on another sight, that basically say MSFS flight characteristics are laughable, once they've discovered X-Plane. Perhaps these people have immediately found all these fantastic models right off the bat. But............... I think it's something else..L.Adamson

Another thing... in FSX I can't get the plane to hold any speed properly, In x-plane I don't even need to look at the IAS... I know what speed I'm at because it doesn't fluctuate...

These type of statements are far too generalized. With so many aircraft available for FSX, which are we talking about? In my experience with FSX, I'm able to easily get my planes to hold speed settings, in climb cruise, and descent................... just like I do in real airplanes. My biggest "personal" disappointment so far, in any flight sim, is the replication of a constant speed prop. Sims don't seem to do so well. It's very noticeable for the landing phase.L.Adamson

That would be relatively all of them compared to X-plane.... but this includes both the PMDG's and LDS with the speed issue.... PMDG 737 in specific with relation to the 10 degree pitch during banking... seems to think its still in second segment climb when it's trying to intercept the glidescope. Just shows how doctored the flight model is... this would never happen in x-plane.

Interesting discussion ;)I'm in a strange position it would appear, in that I've used X-Plane for years and have only recently been able to spend any time with MSFS (FSX in my case). Both sims have their good points, their bad points, and their fans/haters. At the moment I fall into the X-Plane camp but hey, you never know :)A few things I've come across that sprang to mind about comments above...Oversensitivity of the controls in X-Plane - especially in pitch.Apparently the X-Plane flight model doesn't take into account turbulence in the airstream over the tail, which reduces the efficiency of the elevators (and I would guess the rudder - I'm not an aircraft engineer or an aerodynamicist). I'm guessing that would also apply to the other control surfaces to a lesser extent (turbulence reducing efficiency). Good aircraft designers can overcome this shortcoming by modifying figures in PlaneMaker, but few seem to bother.Poor default aircraft supplied with X-PlaneYep, most of them are pretty poor, having been designed for earlier versions of X-Plane with totally different flight models. Apparently this is changing - X-Plane is heading towards having a smaller number of much higher quality aircraft as standard instead of the old quantity over quality model.Vans RV's being inaccurate in various waysVery true, but have you ever read the 'What are these' file that comes with them? Those aircraft are meant as starting points for aircraft designers who can plumb in the figures for their own homebuilt, not as completed aircraft.Setanta

That's interesting you bring that up... my cousin was telling me about the limitation of the airbrakes on the A319 due to spoiled air going over the elevator section. Apparently at 340knots and airbrakes the airplane will pitch up, not sure if it would lead to a stall but I'm sure at 340 knots its not that hard to recover. I agree in the fact its probably not simulated. But talking about spoiled air... I love how you can park a cessna on the runway and have a b52 fly overhead.... instant death and all you see is Sirius...

That would be relatively all of them compared to X-plane.... but this includes both the PMDG's and LDS with the speed issue.... PMDG 737 in specific with relation to the 10 degree pitch during banking... seems to think its still in second segment climb when it's trying to intercept the glidescope. Just shows how doctored the flight model is... this would never happen in x-plane.

The only good X-Plane models are doctored too. :( I think you give X-Plane too much credibility; as though it's a super computer piece of software. What comes out of X-Plane's "plane maker" can be somewhere in the ballpark, entirely wrong.....................but seldom perfection. At that point, the model needs someone with expertise. Lot's of expertise!And it's the same way with MSFS. The better and best flight dynamic designers have been doing this for years. And they've found many work- arounds; as required. X-Plane needs work arounds too. That's why there are invisible flight surfaces, faked ground effect, and simulated percentages of air flowing over the tail. You can't take flight changing items such as vortex generaters and root cuffs; expect to place them on an X-Plane model; and have it act as intended. X-Plane just isn't that powerful. Does someone think that Cessna could have solved it's spin problems & two wasted planes, with it's new light weight high wing.............if they'd tried the vertical stab/rudder in X-Plane first? As to PMDG & LDS, these are both designed by commercial airline pilots with a lot of desktop sim experience. I don't really get into flying simulated commercial jets; so I wouldn't know what pitch angle is exact. But I have flown a lot of GA airplanes, ranging from the Pitt's & Marchetti SF260, to several Piper twins. High performance experimental/kitbuilts are what I really like. And that's the point! I've climbed aboard many X-Plane modes (so to speak), and haven't been all that impressed. I own versions 8 & 9, and have used the demos since the beginning. At the moment, I still prefer some MSFS models, in which the designer is highly experienced in re-creating flight dynamics. These have the "feel", and usually the right response.L.Adamson