As you all know I develop for X-Plane and I have my own road map for X-Plane which keeps me focused on development.....

three very important aspects to flight simulation in general that need to be addressed in order for it to be successful. Two elements that help the end user suspend belief and make the simulator feel more realistic.

 

The first element and the most focused area in X-Plane right now is what I call the "mechanical" elements in X-Plane. Some elements I feel are on that side of the house are;

• Flight dynamics
• Aircraft systems
• Failures
• ATC
• Navigation
• Weather
• Airport Layouts

X-Plane is doing a great job here with a few exceptions like ATC.....

 

In addition there are some aircraft developers closing in on PMDG right now, most notably the 777 or the new Saab.......

 

 

 

The second area, and less focused area, are the emotional elements. These concepts help the user become connected to the simulation by visual stimulation. This is the area I like to focus on. Some things I feel are needed are;

• Seasons
• Global Landmarks
• Basic World Airports
• Accurate Skylines
• Refection Mapping
• Airport Traffic
• More realistic water

Of course I kept out a few things that are already in the works like the HD mesh.......

 

This is where I see the most discontent with X-Plane, its an open market right now and only a handful of people are tackling these elements. Additionally developing scenery in XPX is very intuitive at times but there is very little focus here.....

 

In order for the emotional development to expand 3rd party support is critical......

 

And number three is FPS, without it everything else is a moot....

 

With that said things like HDR should go the way of the dodo bird, my opinion is it only offers a minor benefit in the overall appearance of XPX with a major hit on FPS. Additionally I find it makes development a bit more difficult.....

+1

Finally a post regarding XP that makes total sense and is very well classified. Good job!!!

 

 

So this leaves as the unique explanation that the torque is automatically compensated by aerodynamic effects on wings, tailfin, etc.

 

That's what I think too...

 

Regarding the "steryle" I was referring only to comparisons between X-Plane and FSX...

 

I don't know exactly DCS's approach appart from being also bet-based (well, somehow...), but I'm sure they have tables as well...

 

 

Please open any airfoil in airfoil maker. What do you see? A graphical representation of your CL, CM, etc... tables. When you change values on those beautiful graphics you see there you are actually changing entries in matrices - no more than that - for that airfoil file!  This is a table.

 

Oh, I see! Here you got it wrong! X-Plane uses real life equations to calculate lift, drag, etc. These values are calculated on the fly (CL, Cm etc). You put some constants that are needed in those equations to calculate the lift, drag etc. Those calculation are taking place in real time when you fly in X-Plane. The graph on the right side is the presentation of the values from A=-20 to A=20 (A=alpha or angle of attack).

 

Table means that you use predetermined values with the absent of any calculation.

 

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And some Principles of Flight - 101.

 

3rd Newton's law. For every action there is an equal and opposite reaction. When the prop turns to the right, an opposite force try to turn (roll) the aircraft to the right. When you are on the ground, the aircraft is not rolling cause the reaction of the ground keeps it level. 

 

Now when you lift off, since there is no ground to counteract the roll, the aircraft rolls to the left. But what keeps the aircraft not spinning? Can you give me an answer?  

The aircraft yaws to the left and is this is compensated for by use of rudder-not aileron.

The aircraft yaws to the left and is this is compensated for by use of rudder-not aileron.

That's due to the spiral slipstreaming not the result of the propeller rotation.

Now when you lift off, since there is no ground to counteract the roll, the aircraft rolls to the left. But what keeps the aircraft not spinning? Can you give me an answer?

I've been giving that answer for the last two years around here. I'm very familiar with Newton.

That's what I think too...

 

Regarding the "steryle" I was referring only to comparisons between X-Plane and FSX...

 

I don't know exactly DCS's approach appart from being also bet-based (well, somehow...), but I'm sure they have tables as well...

 

Of course every FM has tables, if you look at it that way, even a full CFD code has a single table with air viscosity, specific gas constant, etc. The level (higher or lower) at which you put that tables can make a difference.

Now when you lift off, since there is no ground to counteract the roll, the aircraft rolls to the left. But what keeps the aircraft not spinning? Can you give me an answer?

 

What makes you think it rolls to the left? X-Plane?

 

When taking up a new student for first flights, an instructor will tell the student about yaw, and the fact that they need some right foot/pedal work, to avoid running off the left side of the runway. Do these same instructors talk about a left roll? The answer is no.

 

In fact, there is a thread at X-Plane org, in which a flight instructor is asking some questions, because he is in charge of some new flight simulators that use X-Plane, for their FBO. Was version 9 as I remember. He's asking about this "torque roll" because it isn't real. He can't have the sims do that. It was mentioned that X-Plane overly did torque with version 9.20, but is tamed somewhat with 9.30. In the meantime, he'll just have to add in some opposite aileron in plane maker, to compensate.

 

 

I tried out the demo for X-Plane 10 for a couple of days now. I actually like a ton of things about it. I'm still so unsure of what to do, migrate to XP10 and forget over 1000 euro worth of FSX addons or stick with FSX. HELP!!!

Fly"em both. Thats what I am doing. I will not give up my FSX investment, and at the same time I am enjoying flying XPX. LOVE"M both.

That's due to the spiral slipstreaming not the result of the propeller rotation.

I find this statement puzzling. There are 4 forces which cause an aircraft to yaw to the left (pfactor, torque,Gyroscopic precision, and spiraling slipstream-not just the last) that cause an aircraft to yaw to the left and is compensated for by rudder-not aileron.

 

Since you introduced yourself above I will do the same. 25 years of flying, 1200 hours, commercial/multi/instrument/ground instructor(I completed cfi traing but for a number of reasons did not bother with the check ride). I have time in almost all common Ga aircraft, but mostly in Bonanzas/Baron's

 

There is no continual left roll in any of these aircraft and why most of them do not have aileron trim. Contrary to much of the aerodynamic talk of engine canting above I believe there is a simpler explanation-if a wing drops dihedral takes control and thru a gentle number of Dutch rolls specified by the FAA (which xplane flunks) the plane comes back to its level state. Pipers are notoriously stable this way-my friend with an Arrow used to brag he did not need an autopilot and he was right-it was unbelievably stable.

 

There are great things the blade element approach does-Dutch rolls from disturbing air, ground effect, the general landing process etc. I don't understand why it is so hard to admit there are areas that it doesn't do so well and hope for fixes in a never ending goal to have a better flight sim.

 

I saw you remarked above once leaving the ground is when one experiences this effect ( at least roll which should read yaw).

 

Actually an old salt taught me a valuable trick. He had a client who had a narrow grass strip and when back taxiing for anther takeoff would turn the plane to the right, run out of runway, have to shut the engine down and push the plane back. This old salt being a stickler for the 4 negative forces suggested he turn the plane to the left the next time where he was able to now by using the left turning forces turn the plane around without getting out. The pilot was adtonished but this old salt drummed into me that most pilots have little understanding of the 4 negative forces and how to use them to your advantage.Wonder if xplane does this-I have never tried but that would be a bonus!

 

...and this old salt when training a new pilot would not allow him to touch the yoke on takeoffs-this to encourage proper rudder usage. Think that would be a recipe for disaster in xplane....

I tried out the demo for X-Plane 10 for a couple of days now. I actually like a ton of things about it. I'm still so unsure of what to do, migrate to XP10 and forget over 1000 euro worth of FSX addons or stick with FSX. HELP!!!

 

I think you should remain with FSX for now, especially if you have so many $$ worth of add-ons. At the moment you can't get with X-Plane what you can with FSX + 1000 $ addons.

 

 

forget over 1000 euro worth of FSX addons or stick with FSX. HELP!!!

 

Stick with both!  You'll have the Best of Two Worlds!!!!

 

They're both excellent simulators.

 

For night flying, X-Plane 10 is very good. For day flying it is also good, although the clouds are not allways very nice to see. With OSM and photo scenery you can add a final touch of plausibility to your scenery (if your area is well covered by both...).

 

I am choosing X-plane for flights in GA aircraft I do not have for FSX, such as the Seneca, F33, Mu2j, the EC-135 helicopter, LES dc-3, Peter's A380, and sometimes FF 777 ( although I prefer the 777 in FSX ...).

 

I also use X-plane when I want to fly a glider, becaus epresently I do not have either Condor or Silent Wings installed, and I don't want to mess around with my FSX install ( stable for the PMDG 777 and the A2A C172, and the Aerowinx Twotter ) and install CumulusX! and the Aerosoft Discus...  The default AS-K21 flies acceptably in X-Plane 10.

 

Looking forward to add the LES Saab 340 to my hangar too.

Those calculation are taking place in real time when you fly in X-Plane. The graph on the right side is the presentation of the values from A=-20 to A=20 (A=alpha or angle of attack).

 

That's exactly how MSFS does it :-)  The Cl, Cm, etc... tables are looked up on-the-fly to determine the corresponding values... Just like in X-plane. A funtion ( with interpolation - what you call "real life equations" in your post ) is used for that purpose.

 

The only difference in X-plane is that you can have various lift / drag generation surfaces attached / making part of your aircracft, and if they're wings, then X-Plane calculates the corresponding values for each of them and finds the resultant. This also would ( theoretically ) allow for better simulation of stall characteristics ( asymmetry, more or less tendency to lower one of the wings, in stall behaviour and recovery, etc...) These various surfaces should also be able to interact with propwash / spiraling slipstream, and allow, for instance, to overcome part of the torque... Clipping, would allow to model situations where, for instance during sideslips / skids, one of the wings becomes obstructed ( by the fuselage ), the effect of sideslips on tiwn props, etc...  Problem is that these details aren't modelled with that much precision, or so exaustively, and so, we have a flight dynamics model which is good but somehow incomplete in some aspects which are crucial - prop effects being one.

 

Also, contrarily to MSFS where stability derivates are set by tables / parameters, in X-Plane - YES - on the fly calculation of those variables is performed, based on the aircraft "design", on the various components and their contribution to the Lift and Drag ( and thrust too ...). Also, in X-Plane you have the option to choose your moments of inertia, on the form of raddi of gyration, or let X-Plane infer them for you. The algorithm X-Plane 10 uses is. IMO, very good, and if some authors decide to tweak the default values that's only because that's one of the ways to overcome other problems...

 

Since, contrarily to MSFS, some values aren't even taken into consideration ( but can be used in MSFS to fine-tune the flight characteristics of your aircraft ), sometimes you end up with a model that performs worse than similar models in FSX.

 

Can anything be done about it? Yes, there are ways to tweak and adjust the flight model in X-Plane, but, the number of available parameters for doing this ( excluding the use of artificial stability ) is actually inferior to those available for MSFS.

@carrotroot

 

What you are probably missing is that X-Plane with 64-bit implementation have gone far ahead from the competition. This is too big to be ignored. Also do not forget that XP10 provides real lighting (aka HDR), which again is ahead of the others.

 

What LR is doing now, and that is why you cannot have any visuals clues, is the modernization of the code up to the latest OpenGL technology. This will create the basis of very stable platform for further development/features addition. But this work takes time to get it right. And again it is not visible.

 

I think they approach it right! If you go in a hurry and put staff in, then you will come up that is useless...and then you have to run to fixing things around probably ending in a total mess.

I have owned xp10 for almost 2 years and you mean to tell me that in 2 years they were too busy to add generic skyscrapers to the autogen? Or how about sceney errors such as Botany bay which is still filled in. If was fixed internally then it should be pushed out quickly... not left to linger until they get around to some future recut a few years down the road.

 

I can understand that it took significant programming resources to go 64bit but the art assets do not require programming. You just have to hire some 3d artists to build your artwork.

 

For me 64bit is meaningless if the areas I fly (mostly around cities) continue to look unrealistic. X-plane 10.30 is going to have to really wow me on the cities going forward. Unfortunately by the time that happens P3D 2.0 will likely have been released. It doesn't make much sense to wait around for LR to get hens in order, when Lockheed's product will do the same HDR and global lighting effects and everything else I was expecting xp10 to have by now right out the box from day one.

 

LR has had 2 years and in my opion they could not capitalize on the opportunity provided them.