Ed, where did I write it  is an airfile editor? I wrote tool, not editor !

 

Airwrench also comes with a User's Guide anyone can download and read.

Yes... and the misconception will be there. I just want to ensure people truly understand that AirWrench is not the same type of software as Aircraft Airfile Manager is.

As I understand it, the code base which LM bought from MS was stock FSX code with the 'old' FD engine.

 

 

Hi ErichB and others commenting on this. First of all I am probably a vessel rather than an expert. However, I own a number of planes in both FSX and P3D2 - Milviz C310R and B-55, Razbam Metroliner, Carenado PA28 Archer, Aerosoft Twotter - and when I fly them,  with trim etc set exactly the same, there is a noticeable difference in flight characteristics between the two simulators. For example, take the Milviz C310R - if I take off with V trim set to 0,  the FSX version climbs more steeply, and requires more down trim to get it to level off than with the P3D2 version. Same thing with the Milviz B55. The C310R P3D2 version also seems to be less "jumpy" during landing. The Razbam Metroliner also seems to have different dynamics: just after rotation and takeoff, I find that with the P3D2 version I have to keep the throttles at full a bit longer to achieve a stable condition.

 

Therefore, I wonder rather the FD engines are the same between the two simulators. Do the people who are stating this know for sure, or do they just "understand" that's the case?

People who make the claim believe it is so because ESP came from FSX and Prepar3D came from ESP. They're just assuming that there are zero changes to the core sim. They don't know.

People who make the claim believe it is so because ESP came from FSX and Prepar3D came from ESP. They're just assuming that there are zero changes to the core sim. They don't know.

 

Do you know?

Do the people who are stating this know for sure, or do they just "understand" that's the case?

 

I honestly don't think the people who always spout off about things here truly know anything for sure unless they are insiders.

 

''The problem with the world is that fools and fanatics are always so certain of themselves, but wiser people are so full of doubts'' - Bertrant Russell

 

 

Kind of sums up the world today

Hi.

 

I'm another enthusiastic amateur with a PPL also interested in Erich's question and have spent some time trawling the interweb trying to learn about this topic. From what I can make out in the ESP documentation on .air files, my understanding is that (a little simplistically) the Flight Dynamics Engine within FSX/P3D is passed the parameters embodied in the .air file and uses these to calculate at any point in time the aircraft's movement vectors. So, for example, if an aircraft moving through the simulated world has it's angle of attack progressively increased (e.g. by pitching up with the elevators whilst on idle power) eventually the data concerning lift vs AoA will become a limiting factor in the calculation and the aircraft will stall. Some of the contributors above allude to simplifications/deficiencies in the algorithm such as it not seemingly being able to consider multiple wings. I would guess that this would manifest itself as an inability to model a spin induced by for example the left wing(s) stalling before the right wing(s). I've read elsewhere (in an X-Plane cathedral) that FSX's FDE cannot model asymmetric configuration in twin engine props. 

 

One aspect I can't see in the sample .air files is any control of thrust angle relative to the aircraft, which would imply that the FDE is incapable of modelling vectored thrust. Given LM's involvement in the F-35B & F-22, I can but hope that this is on their to do list.

The "workarounds" seem to me to exemplify the inherent weakness of the approach to designing realism into these simulated aircraft. It seems that designers lean on the support for unrealistic factors within of the FDE's algorithms to create desired behaviour - e.g. no vectored thrust? - then tell the engine that the aircraft has magic flaps which can create impossible amounts of lift for the tiniest bit of forward motion. To my mind, the FDE should NOT allow values that could not hope to be achieved in the real world. (John Farley makes a good case in his book for simulators that simply stop when unknown conditions occur.)

 

However, this would mean that the sim provider would HAVE to change the FDE to support an aircraft whose means of flight is achieved with factors not already built in to it (and no doubt do so in a way that did not adversely affect legacy aircraft).

 

So it seems to me that there are 2 fundamental problems which limit fidelity of flying characteristics:

1) A flying model that was deliberately simplified to cope with PC processing limitations

2) .air files that do not match the real aircraft's performance (either deliberately so as to address an omission in the FDE model or because the aircraft designer has no access to/interest in real data)

 

I don't want to take the thread off topic but would be very interested if anyone can point me in the direction of any information on how to go about implementing an external FDE. A search for "6DOF VTOL" in youtube suggests it can be done...

 

Cheers,

 

Z

To quote the Prepar3D website:

 

"Training meets reality with Lockheed Martin’s Prepar3D® simulation software. Private pilots, commercial organizations, militaries and academia rely on Prepar3D for immersive, experiential learning."

 

Training meets reality. Really? Do the default P3D aircraft have accurately tuned flight dynamics?

One would hope so but I see very little mentioned about it on their website.

 

For now the first thing I install after a fresh P3D reinstall is my RealAir SF260.

Do you really think we use default aircraft for real world training? Seriously???

Do you really think we use default aircraft for real world training? Seriously???

 

Pardon?

I expect he means something like LM's primary Prepar3D customers (large, well-funded entities using P3D for real-world training) tend to contract someone to build custom aircraft to their specs.

P3D is really just the engine. For most commercial applications (eg flight schools) I doubt the default aircraft would even be found on the installation.

 

To go into the topic of flight model accuracy, the fsx model, while it does have some limitations that other engines like X-Plane or DCS (the latter requires 3rd party devs to create their own from scratch) don't have, there are ways around those limitations, even without using an external engine. I cant go into the technical details but lets just say if such things weren't possible then some aircraft (specifically those by PMDG and FSLabs) would behave vastly different from what they actually do.

P3D is really just the engine. For most commercial applications (eg flight schools) I doubt the default aircraft would even be found on the installation.

 

To go into the topic of flight model accuracy, the fsx model, while it does have some limitations that other engines like X-Plane or DCS (the latter requires 3rd party devs to create their own from scratch) don't have, there are ways around those limitations, even without using an external engine.

 

I was of the understanding that DCS supported 4 options for FDE. (See here), only one of which (the EFM) utilises an external model.

 

I cant go into the technical details but lets just say if such things weren't possible then some aircraft (specifically those by PMDG and FSLabs) would behave vastly different from what they actually do.

 

Please do go into details. As I suggested above, the common approach would seem to be to provide distorted values to the engine that whilst may work for a specific mode of flight may well cause unintended (and undesirable) side effects. Take for example a popular Harrier add-in which adds 2 additional engines which point at the ground in order to achieve VTOL. Point the nozzles fully aft and open the throttle and the sim has the aircraft leaping into the air rather than along the runway. Hmm.

 

Z

Before i got bored with it, I experimented with Simconnect to model a single-engined aircraft VTOL that rose climbed and decended vertically, and responded to pitch, roll, and yaw commands. Even FSX/Simconnect can do a lot more than some people recognise

Before i got bored with it, I experimented with Simconnect to model a single-engined aircraft VTOL that rose climbed and decended vertically, and responded to pitch, roll, and yaw commands. Even FSX/Simconnect can do a lot more than some people recognize

 

Put it this way, DCS actually allows the dev to do what they want. The AFM, SFM, and PFM are only existing models that can be used. The EFM opens the way for other options as well. Technically one could build a model based on the FSX airfile system and plug it in.

 

And no, I cant or rather, wont go into the tech details because they are in use where I work. Company secrets at this time. Suffice to say though, such methods of getting around the sim limits as you describe are rather...amateur. Creative yes, and for those who do not have the tech at their disposal to do better its not a bad idea. But there are more effective methods.