Questions for DEVS

[mikoyan]

Questions for DEVS

Before I Star I want to thank you guys for producing such a great sim (The best sim!)

When flanker 1.0 was released it had a very similar flight model to the flight model we have in flaming cliffs, but it was different in flanker 2.0, I will like to know what the reason behind those changes was.

In flanker 2.0 the su-27 was very easy to stall, but now it is better at high alpha. Why you guys made it stall that easily?

I also remember that on flanker 1.0 it asymmetric thrust could evolve into a flat spin but now it is more forgiving when you lose an engine. Why?

[mikoyan]

:cry:

[EscCtrl]

Maybe the older versions were less realistic? I doubt many could answer that exactly as few if any here have flown flankers. I'm sure there's data about that though.

 

The asymmetric thrust for example is probably more realistic now. Unless one engine is afterburning and the other is at 0% I doubt the plane will spin. Tomcats had that problem but I haven't heard much about it on other aircraft. If you lose one engine on LockOn what tends to happen is the working engine maxes out at 100% (no afterburner) and the other idles. So the power ratio between them is not too high, whereas the tomcats that had this problem IRL would spin when only one afterburner ignited (the F14As engines were unreliable)

 

Don't know if that helps explain anything, yeah I know it's difficult to compare F14s and Su27s but it was the only real life comparison I could think of.

[Kula66]

I thought what made it worse in the Tomcat was that the engines were widely separated, like the 27.

[EscCtrl]

I thought what made it worse in the Tomcat was that the engines were widely separated, like the 27.

 

Should have mentioned that too. yeah because they wanted to fit a wide weapons channel between the engines so they are further from the centreline increasing their moment, a coupling effect ensues and with a large power differential the plane can spin. I'm other aspects of the design also have an effect on this spinning too which would explain why other fighters tend not to encounter this type of trouble.

[mikoyan]

thanks for the reply,

tha's what I

tough.

The effect was more ponunciated on flanker 1.0

[RvETito]

I'm pretty sure the huge tail fins(with big rudders) in combo with the underfuselage fins are enough to compensate any thrust assymetry the Flanker may suffer.

[ericinexile]

Every Multi-engine airplane with non-centerline thrust will have a speed (Vmc) below which directional control will be lost when flying with one engine inoperative and the other at 100%. For some airplanes, this speed is at or below stall. For most, the speed is higher.

[britgliderpilot]

Mmmn.

 

 

On a semi-related note - I remember a gunzo fight in Flanker 2.5 where I had one engine shot out and a tailfin removed.

 

Managed to recover and return to stable flight - but as it became obvious that I wouldn't make it to the airfield I had to apply power . . . .

 

Full power and one tailfin sent it into a flat spin from which there was no recovery, even on zero power. Despite crashing, I did rather enjoy that moment ;)

 

 

Changes to the flight model will almost certainly depend on the information available to the development team at the time. It's not just done for fun.

 

For Su27 Flanker, my understanding is that a limited amount of technical data was available - but on the other hand, IIRC one of the test pilots gave some input.

 

Since then, flight manuals have been released to the general public, giving a much better idea of the performance of the aircraft.

[Weta43]

In 1.12a I once went under a bridge a bit too high in the 27 & took the tops off both tails.

No warings or anything & I flew away, turned towards the course I had been on OK, banked, & then went into a flat, unrecoverable spin.