Free Flight, Free Speech

Oh yes, that bouncing. I have seen people flying into mountains, bouncing off and happily continue their flight. But i actually meant in the air. I have had about every jsb airliner in flightgear, and they all have more or less severe problems. I am tired of wasting my time test flying them now. Jsb jetliners can simply not be modeled by a non-pilot without wind tunnel data. Here are a few of the nature defying behaviours i can remember from the top of my head.

- Insane climb rates at high alt (above fl 300), as if the plane is still in thick air below 5000 ft.

- When trying to stall, the plane just stops slowing down at minimum speed, and you can fly on forever with engines idle.

- No effect whatsoever from configuration changes. Taking off with full flaps is a breeze, as if you are on take off flap settings.

Just think of how unnatural you have to land planes with such mad aerodynamics. When i hear here that people are trying to learn flying from this mess, i get really worried.

The exceptions on the jetliner front are the tu154 and a330. They must have had wind tunnel data, or if they made the fdm up, someone that knows about aircraft moving through air, like a pilot or aircraft designer. Someone without any of such experience or wind tunnel data should stick with a good generator. Average is better than nothing, or making things worse.

Kind regards, Vincent

And on a total immature sidenote: Girls dig guys who can cook ...

jwocky wrote:And on a total immature sidenote: Girls dig guys who can cook ...

You are speaking in Nonsense this troubles me. The sense you are making is not!

legoboyvdlp wrote:

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Video games are pointless and stupid. FlightGear is for learning, and simulating flying aircraft, which is a complicated task to achieve.


would make a very nice signature.

I agree!

KL-666 wrote:I do hope you have a good reference to tell good from bad modeled. In what i see in fg is that yasim makes a reasonable average, so that planes are just slightly off fdm's. But jsb really needs input, else it is nothing, worse, totally nature defying. The problem is that hardly any manufacturer will publish their wind tunnel data. So jsb stays a hopeless wild guess of the fg developer, which is ... nothing.

Kind regards, Vincent

Of course, I have found some quite a few models that seem to have a decent FDM based from Wind tunnel infos. It is a funny confuse between good and bad, but some planes have not able!

Well well well ...

First of all, yes, JSB is more work intensive to build. Second, many JSB planes are actually more realistic in their behavior than the average YASIM plane. You lose lift in a side slip, JSB can simulate that, YASIM does not. You have a thing called ground effect. JSB can simulate it, YASIM does not. The dampers on the different gears of a plane work independently. JSB can simulate that, YASIM does not. Some planes have gravitation fed fuel systems. JSB can do that, YASIM does not. And so on and so on.
The aerodynamical description of a plane is much more complex with JSB but since it's expansible, I can basically do everything and like in YASIM, I can of course fill in the gaps in the data with some kind of best guess, the same as Yasim does.
The real problem is, JSB, because I can play around on everything, calls for a much deeper knowledge about basic engineering principles and a lot more detail work which can be a critical bottle neck if developers run out of time. I just have a BV-138 in work. Diesel engines! Two different kinds of flaps! A very weird aerodynamics due to her weird shape. Multiple pressure points. A very high sitting CG. Very different load situations. Good luck in trying that with YASIM ...

KL-666 wrote:There is no guarantee whatsoever that a flightgame is a representation of reality in any way. I am not talking about a slightly off fdm, but about completely nature defying behaviour. Flightgear is full of such fdm's. One my learn very adverse reactions from such planes, which have to be beaten out in flight school proving not to be an advantage at all. So if you ever want to fly for real, take this game with a big grain of salt. Play it for fun, but do not try to learn flying from it.

Kind regards, Vincent

It's not so much how the plane flies, there's no way to get a "feel" for the aircraft without actually flying one.
But you can learn lots of other things that will help in real life flying. VOR and ADF nav., instrument scans, checklists, etc.

I was tempted to write something about attention span, teenagers and thread drift....

MountainFlyerN22 wrote:there's no way to get a "feel" for the aircraft without actually flying one.

There is indeed no way to know how a specific plane behaves exactly. But there are laws of nature by which they all have the same effects, when doing the same thing. Only the amount of effect is unknown. But game planes that behave completely outside of the laws of nature are the ones i am complaining about.

For the rest about learning navigation etc.., you are probably right.

Kind regards, Vincent

jwocky wrote:And on a total immature sidenote: Girls dig guys who can cook ...

Interesting self-realization: I never knew I would like cooking for like the first 30 years of my life but now I enjoy them cooking - very much! Maybe it's an age thing.