Have you ever oppened Airfoil Maker?

[jcomm]

Many things have been written about X-Plane and it's approach to flight dynamics modelling - the BET.

 

It's IMO wrong to argue about BET vs non-BET based flight simulation engines. I am much more interested in finding out:

 

1) What is missing sometimes on most aircraft models designed for X-Plane 10, starting with some of it's default aircraft;

2) What can be done to bring a model as close as possible to the behaviour and even some performance figures we can compare with it's real counterpart;

3) What is missing and could / should be added in order to get X-Plane's approach to an even higher level of performance.

 

I have wondered in the past about the true advantages of BET. Well, my oppinion has changed, and so have changed the oppinios of those who

use a same approach to build their very high fidelity simulations, of which Eagle Dynamics with DCS World, 777 with Rise of Flight and soon IL2 Sturmovik BOS, but

also the Flight Unlimited series for instance, are good examples.

 

The change in oppinion stemmed from my remote experience with the first version of FLIGHT UNLIMITED ( by that time we had FS5 too ), then FU2 and FU3,

and very recently, DCS World ( and soon IL2 Sturmovik BOS ). I consider DCS World, and in particular the P51d, the three helicopters, the most perfect flight simulation

add-ons in terms of flight modelling I ever used - period!

 

I have questioned myself about the possibility of getting the same results with X-Plane 10, and have exchanged many emails with aerodynamicists and forum members

at various sites, about this subject. I am converging towards a big YES WE CAN! ( probably not the best connotation, but I am not American... ).

 

Fact is, when I test some aircraft, being it default, freeware or even payware, I sometimes find behaviours that leave me quite disappointed. I used to think to myself - how

can such a "extremely realistic" flight simulator fail so miserably to reproduce such simple aspects as pitching moments from lift augmentation surfaces, stall behaviours, etc?

 

Well, my answers started emmerging with some more insight into the ACF and Airfoil data associated with those models.

 

I could mention a few remarkable examples of aircraft where, for instance, some typical stall behaviour described by books / reviews /etc...

revealls exactly the same way I see it replicated in X-Plane 10, and I could of course also give many examples of some, sometimes even top payware / freeware examples

where you'd better not even try it in order not to get undisposed.

 

What I have dediced to do was, on some of those models, to try to gather some RW data, and edit the models, first in PM then in it's sattelite app - AIrfoil Maker.

I am almost sure Airfoil Maker is probably the X-plane app we users have ran the least. Well, we should really at least open it, and try to understand the potential it

offers for aircraft developers to nail their creations as good as possible to RW data, flight tests etc...

 

Some good, detailled, very well designed models I have used / am using in X-plane 10 are, for me, the proof of the true potential that Plane-Maker, Airfoil-Maker, and

X-Plane's approach to flight modelling REALLY offers to anyone willing to dedicate seriously to aircraft design for this simulator.

 

NOTE: Please notice how I haven't even tried to compare all of this with MSFS!!!! Please don't jump into this thread based on that assumption of the contrary. Jump in to comment on

your own ideas about the way X-Plane design tools can be used, what could be made easier / better, etc...

[Murmur]

Many things have been written about X-Plane and it's approach to flight dynamics modelling - the BET.

 

It's IMO wrong to argue about BET vs non-BET based flight simulation engines. I am much more interested in finding out:

 

1) What is missing sometimes on most aircraft models designed for X-Plane 10, starting with some of it's default aircraft;

2) What can be done to bring a model as close as possible to the behaviour and even some performance figures we can compare with it's real counterpart;

3) What is missing and could / should be added in order to get X-Plane's approach to an even higher level of performance.

 

Now that the spiral propwash is being worked on, I'd say:

 

.) better modeling of fuselage aerodynamics;

 

.) from graphical flight model output, looks like upwash is missing? In subsonic regime, there should be upwash ahead of lifting surfaces, and not only downwash behind them; this could be particularly important for canards, I think;

 

.) the modeling of spanwise airflow; this should have mainly an influence on winglets and the stall of swept wings; probably it's gonna require an increase in the complexity of the flight model, by one order of magnitude at least, so I don't think this will be implemented anytime soon, or ever at all;

 

.) customizable coefficients for transonic (and supersonic?) regimes;

 

 

Not strictly related to flight model, but:

 

.) more complex and customizable performance curves for engines (jet, recips, turboprops);

 

.) revised ground friction model;

 

.) revised water drag model;

 

 

I think just these improvements would be all is needed, since the remaining inaccuracies of the current flight model can be tweaked/overcomed inside Plane Maker/Airfoil Maker without using external plugins.

 

The pessimistic part is, I doubt we'll see anyone of these changes implemented anytime soon, except maybe for better fuselage aerodynamics. :smile:

 

 

 

NOTE: Please notice how I haven't even tried to compare all of this with MSFS!!!! Please don't jump into this thread based on that assumption of the contrary.

 

I'm also pessimistic that this thread is not gonna turn into what you fear... :smile:

[Geofa]

In addition to the above great list I'd like to add a feature I have been asking for since the early days of xplane-better stability.

 

Interestingly even since version 9 which I basically scrapped because I found the aircraft so uncontrollable, stability has been improved with every version-and the torque bug will be a further improvment when fixed. This is the main reason I have stuck with xplane 10 for an extended period.

 

However, (and other sims suffer from this to a degree)-I would really like to trim a plane and not have to make such continual corrections as needed now. For instance-when I level out at altitude, se tcruise  power/prop settings and trim the plane-not much later it will start quite a powerful climb. Trim again for level flight, and a little later the same climb starts again. Just too much retrimming going on all the time.

 

For me, this can be the most frustrating thing about flying sims on a flat screen monitor-but the effects here still can be quite exagerated. Again, there are very specific stability tests the faa requires-perhaps at some point they can be accomplished.

[Mountain Man]

 

 

I am converging towards a big YES WE CAN! ( probably not the best connotation, but I am not American... ).

 

It's O.K.  Bob the Builder said it first.