SAAF JAS-39C Technical Data and Discussion

Yeah that’s a deal breaker for Gaijin lmao

I mean there is only like maybe a dozen or so people that play top tier sim and aren’t absolute amoebas.

The average Gripen player in sim is just carried by Aim-9M and having a billion flares.

Even starting behind me…this highly skilled sim player died to me almost instantly in spite of being in a better maneuvering plane.

Previously he was trash talking in chat about US players = bad, and from the looks of his stat card he primarily played F-16C in the last patch.

Sadly. Wish you prop people would play some more top tier lol. Last time I met you in sim was Netz vs Mig29 pre nerf
Btw I’m the Apollo guy in your discord

Please bookmark this thread and read what you’ve posted here again after you’ve graduated. I hope you see how foolish your posts here are.

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enlight us

Alright let’s do a quick sanity check (always good to do this for complex interactions)

The thought experiment

Let’s say we have a plane with some known TWR, which we will play with in this thought experiment.
We know this plane’s best sustained turn rate, at which point thrust = drag.

Increasing thrust

Now let’s increase the TWR of the aircraft by increasing thrust. This suddenly makes the thrust bigger than drag, causing the aircraft to speed up, going around the same circle[1] but faster, hence rate increases.

Decreasing weight

We could also increase TWR by reducing the weight of the aircraft, which we do by reducing its mass. This will increase the centripetal acceleration created by lift, hence the turn radius gets tighter. The drag produced stays the same, so we are going at the same speed around a smaller circle, so rate also increases.

Yes, TWR does not tell you the full picture, but it has a strong correlation to sustained turn rate.


[1] Turn radius is mostly independent of speed, as long as you’re reasonably faster than stall speed, and your control surfaces have no problem deflecting.


As for your comment on gliders, they do have a TWR 0, and they do not have a sustained turn speed, not without losing altitude. A glider cannot sustain a turn without also diving, so it is losing energy constantly. A horizontal sustained turn assumes constant altitude.

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but then again, why bother with TWR when you only need thrust?

Well, 80 comments later and the T/W argument continues. Gaijin modeled it to do ~20-21 deg/s on half fuel. The test I shared previously that was used to show it can’t do 20 deg/s was at 30 minutes fuel load.

Sustained turn rates are pretty much on par with F-16 currently.

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Weight is proportional to mass. And mass is a big factor in determining the turn radius, which determines your turn circumference at any given speed. A smaller circumference at any given speed results in a higher rate.

It does not affect the sustained turn speed. But it makes the circle smaller, increasing rate.

This is one small piece of the puzzle, doesn’t take flexing a degree to figure this stuff out. What we lack is solid information on the jet, and it would only be partially solved by a CFD model. Until someone goes to that length, we have little to go off of but public sources.

I trust Gaijin has done an earnest job modeling the aircraft with the new information we have forwarded. I see no point in this argument from which y’all are discussing formulas and not the data that would be useful within them.

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Agreed.
Hope I find some good stuff in the books. I just ordered another different 192page one on the Gripen from 2003. Really hope it’s not just a picture-book or something lol

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Ask your engineer friend…

Actually speed is function mass and acceleration.
T−D=m⋅a

a=dv/dt (delta v, delta time)

T-D=m*(dv/dt)

T is the thrust of the engine,
D is the aerodynamic drag force,
m is the mass of the aircraft,
a is the acceleration of the aircraft.

From equation you can see if you raise mas you need increase thrust or lower drag to sustain speed.

ok then explain to me cases like F-5E having a TWR of 0.73 at 50% fuel and 2 x aim9, beating a mig21bis in same config having a TWR of 0,945. oh and the F-5 has a better STR than the mig21 in the same conditions.

For real…

I can explain it to you with all math behind it. But your altitude and your friends to my person it’s just awful. And I just feel that it’s will be waste of my time.

But your friends are experts here so probably can explain it to you…

since the first time i asked you answered me smelling with entitlement.
now don’t be a coward trying to cut it up with a simple “huh i can explain but you’re a waste of time so bye bye”

again, one last time, can you explain to me why the F5E has a better STR than a mig21bis despite it having a lower TWR? or should i ask to someone more polite than you?

This is because the F-5E is overperforming severely.

i should clarify, i’m talking about irl data, not in-game

Depends on airspeed, the MiG-21bis technically beats it at low speed and instant turn rate.

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yes, i took this as a reference, you have a wide range between mach 0.5 and 0.8 where F-5E does have a superior STR than mig21

considering the lower TWR it is quite a performer amirite?

I have a suspicion that this guy doesn’t seem to like confrontation much @draghettoverde
You’re just wasting his time lol

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