Su-27 turning perfomance vs f-15

[rami80]

I was in the Guns and roses server a couple of days ago, and I was dogfighting an F-15. I believe both planes start out with 40% fuel. When I forced the F-15 into a turn fight where he was weirdly enough able to out-turn me (I was maintaining 600-700kmph) even the F-15 pilot was surprised. We switched roles, when holding 320-400 knots I am always able to out turn the Su-27, even when my speed drops below 320 knots.

 

I thought the Su-27 had better performance, should I not force the eagle into a turn fight? It seems that even when the eagle slows down it regains speed really quickly. While the Su-27 just becomes a slouch below 550kmph and refuses to gain airspeed.

[Hadwell]

i think the su-27 can out-maneuver a f-15 in a stall fight, you have to get yourself slow enough, and keep yourself slow enough, with as much AOA as physically possible, so that engines have nothing to do with the fight other than keeping yourself from hitting the ground.

Edited June 2, 2015 by Hadwell

[Exorcet]

Best way to test this is take a F-15, fly a circle and see how many g's you can pull before losing speed and then do the same with the Su-27.

 

One thing, at 40% fuel, the Flanker is holding more fuel in relative and absolute terms than the Eagle is. The F-15 without external tanks also accelerates brutally fast at high speed, so if you give it a chance to accelerate, it can recover energy lost in turns.

 

This data is with missiles 80% fuel, 30,000 ft, but I think the F-15 would probably keep the edge when clean:

 

F-15 2-6-0 80%

KTAS - seconds

500 - 0

600 - 16

650 - 26

700 - 40

750 - 56

800 - 1:13

 

Su-27 2-2-2-4 80%

KTAS - seconds

500 - 0

600 - 21

650 - 39

700 - 1:02

750 - 1:29

800 - 1:59

[Ktulu2]

The Su-27 is generally better in turning fights. But as hadwell said, if you aren't close to stalling, you can beat your opponent. But if you hapenned to dodge some missiles before the dogfight and have lost your speed, the F-15 won't do much (i'm talking 200-300 kts). I do know the flanker has better turning performances than the F15 and I used to see a difference when I fight an 27 instead of a 15. Although it does about 2 months I haven't played (tooooo much exams) maybe things changed. About the F15 gaining speed back, it will, but if you can get your opponent eagle to go below 250KTS its a piece of cake to keep him at thoses speeds as long as your keeping the fight horizontal and he's pretty much done.

Turning speed is often limited by over-g'ing so maybe the flanker was coming faster that you and you were able to turn faster because you were slower. And it's normal for the F15 to turn well at about 350-450 knots, it's where it's cornering speed is (more 400 than 350 though).

[Svend_Dellepude]

@Rami80

That was Ragnarok and you that day wasn't it? I was there too.

Remember that both planes are in beta and IMHO the F-15 (dunno about the SU-27) still has some way to go, so that might change. But as said by the other posters, try to drag all the speed out of the eagle and he should be yours. :)

[gavagai]

I've heard from a real F-16C pilot that the F-15C out-turns it below 350 knots. I have no idea about the Su-27, but the idea that the F-15C lacks maneuverability can be a fatal underestimation.

[pepin1234]

First Su-27 vs F-15, the Su-27 is heavier than the F-15 without missiles.

 

Now you have to add the weigh of the Russian missiles to the Su-27, and here the F-15 is still in advantage. The R-27ER vs Aim-120, The R-27 is heavier twice than the 120.

 

So the best payload for the Su-27 to go into dogfight with F-15 is 4 R-73 only, here the F-15 should died surely.

 

My advise is shot all the R-27 in override if you are already in dogfight, till you only get your R-73 missiles. Here the game change.

[combatace]

When you see F-15 and Su-27 climbing 38,000 meters, you know things are not realistic.

[rami80]

@Rami80

That was Ragnarok and you that day wasn't it? I was there too.

Remember that both planes are in beta and IMHO the F-15 (dunno about the SU-27) still has some way to go, so that might change. But as said by the other posters, try to drag all the speed out of the eagle and he should be yours. :)

 

Yep that was it. It seems impossible to drag the Eagle out of speed, well unless you have less than 10 hours of flight time in the eagle like me:lol: Even if the pilot messes up at one point a few seconds of relaxed turning are more than enough to get it back to speed.

 

In regard to other replies in the GNR server there are no weapons on the pylons.

[rami80]

When you see F-15 and Su-27 climbing 38,000 meters, you know things are not realistic.

 

Funnily enough the record was set by the Mig-25 in 1977 and it was around 37,000 meters IIRC. I don't think the flight models are completely tuned for high altitudes.

[Dell_Murrey-RUS]

I was in the Guns and roses server a couple of days ago, and I was dogfighting an F-15. I believe both planes start out with 40% fuel. When I forced the F-15 into a turn fight where he was weirdly enough able to out-turn me (I was maintaining 600-700kmph) even the F-15 pilot was surprised. We switched roles, when holding 320-400 knots I am always able to out turn the Su-27, even when my speed drops below 320 knots.

 

So, both modules (Su-27 and F-15C) are beta. :)

 

F-15C now have bug with turn-rate. All speeds < 1M F-15C have 15% better turn-rate than Su-27.

I hope next patches DCS and modules will correct that problem. :)

 

However, when I fight at Guns'N'Roses server, my Su-27 has a significant advantage against the F-15C, which is trying to win the fight by turns. I don't remember anyone 'eagledriver', which was able to win my battles in turns against the Su-27. Su-27 was always better F-15C with 200-650 km/h.

F-15C better on verticals. That plane live on hi speeds.

[*Rage*]

It seems the Su27 has a much more sophisticated and realistic flight model than the F15.

[Mowgli]

It seems the Su27 has a much more sophisticated and realistic flight model than the F15.

 

comparable to the Eagle but superior in many respects:music_whistling:

[Hummingbird]

I've heard from a real F-16C pilot that the F-15C out-turns it below 350 knots. I have no idea about the Su-27, but the idea that the F-15C lacks maneuverability can be a fatal underestimation.

 

I've heard the reverse, but thats the problem with subjective opinions like that, esp. since were aren't given details of load outs.

 

The F-16C will outturn the F-15C at pretty much all speeds though, as evidenced by actual performance charts. They are the closest at low speeds though, and a really light F-15 would probably just be able to outturn a regular loaded F-16C. Above mach 0.5 however the F-16C pulls ahead rather markedly in STR.

[Dell_Murrey-RUS]

superior in many respects:music_whistling:

 

Unfortunately, it is not.

The Su-27 is very well behaved at speeds of less than 700-650 km/h and an altitude of 4000-6000 meters. The dynamics of acceleration in the Su-27 (without missiles) is slightly worse than the F-15C. At the same time the F-15C is better dispersed (restores speed) at any altitude and become more agile at speeds above 750 km/h and significantly exceeds the Su-27 at altitudes above 6000-7000 meters.

If you take both aircraft with missiles, then the F-15C, increases its advantage because Su-27 missile maneuvers worse.

 

Perhaps the most important reason why the F-15 is not necessary to engage in close combat with the Su-27 - the presence of R-73 and the helmet-mounted target designation.

If such a system and the R-73 was not, then the F-15C in the group close combat would fight to keep dignity in the battle against the Su-27.

 

In general, in the simulator, both fighters have to be very strong points and weaknesses. The winner is the side that could not allow the enemy to take advantage of their weaknesses and at the same time took advantage of the weaknesses of the opponent. :)

[rami80]

So, both modules (Su-27 and F-15C) are beta. :)

 

F-15C now have bug with turn-rate. All speeds < 1M F-15C have 15% better turn-rate than Su-27.

I hope next patches DCS and modules will correct that problem. :)

 

However, when I fight at Guns'N'Roses server, my Su-27 has a significant advantage against the F-15C, which is trying to win the fight by turns. I don't remember anyone 'eagledriver', which was able to win my battles in turns against the Su-27. Su-27 was always better F-15C with 200-650 km/h.

F-15C better on verticals. That plane live on hi speeds.

 

So what you're saying is that if the two planes are just circling around each other at their corner speeds, then right now the F-15 has the advantage. The only thing the Su-27 has is its instantaneous rate?

[theropod]

i am waiting for the final versions to compare fairly.

i guess i'll wait more:)

[*Rage*]

comparable to the Eagle but superior in many respects:music_whistling:

 

Unfortunately, it is not.

The Su-27 is very well behaved at speeds of less than 700-650 km/h and an altitude of 4000-6000 meters. The dynamics of acceleration in the Su-27 (without missiles) is slightly worse than the F-15C. At the same time the F-15C is better dispersed (restores speed) at any altitude and become more agile at speeds above 750 km/h and significantly exceeds the Su-27 at altitudes above 6000-7000 meters.

If you take both aircraft with missiles, then the F-15C, increases its advantage because Su-27 missile maneuvers worse.

 

Perhaps the most important reason why the F-15 is not necessary to engage in close combat with the Su-27 - the presence of R-73 and the helmet-mounted target designation.

If such a system and the R-73 was not, then the F-15C in the group close combat would fight to keep dignity in the battle against the Su-27.

 

In general, in the simulator, both fighters have to be very strong points and weaknesses. The winner is the side that could not allow the enemy to take advantage of their weaknesses and at the same time took advantage of the weaknesses of the opponent. :)

 

I was talking about the PFM in game, not real life dynamics. As in EDs 27 PFM is more thorough than BSTs 15 PFM. At least thus far.

[blkspade]

Perhaps the most important reason why the F-15 is not necessary to engage in close combat with the Su-27 - the presence of R-73 and the helmet-mounted target designation.

If such a system and the R-73 was not, then the F-15C in the group close combat would fight to keep dignity in the battle against the Su-27.

 

Pretty much this. Options expand in as an eagle driver when you're not worrying about 73s/ETs. Half the fight is won by the flanker getting those IR missiles off at you before merge forcing the eagle to generally come off the throttle and lose energy maneuvering. That is then further exacerbated by the concern of a helmet sighted shot if you've made it close enough at a somewhat decent energy state. I'm almost certain some guys fire R27s way too close (with no chance of hitting) just to trigger a similar response.

[GGTharos]

So, both modules (Su-27 and F-15C) are beta. :)

 

F-15C now have bug with turn-rate. All speeds < 1M F-15C have 15% better turn-rate than Su-27.

I hope next patches DCS and modules will correct that problem. :)

 

This is more of a power bug and it will be fixed. F-15 was accidentally tuned with 15C weather performance for 20C weather, IIRC.

 

Su-27 was always better F-15C with 200-650 km/h.

F-15C better on verticals. That plane live on hi speeds.

 

That is how it should be. Don't get into a turning fight with a flanker at low altitudes. :)

Regarding your other post about R-73: The R-73 is (IMHO) one of the major reasons why I commonly hear the the AMR (Acceptable merge criteria) for F-15 with Su-27 is something like merging with much fewer flankers as there are eagles.

 

If you consider a 4v4 scenario, AMR might be 4v3 to 3v2 after BVR.

 

It seems the Su27 has a much more sophisticated and realistic flight model than the F15.

 

Only a temporary issue. Don't expect your fight to get much better ... the F-15 will lose some things and gain others. A more realistic F-15 FM will enable a pilot who thinks and flies like a pilot (as opposed to a vpilot :) ) to do a lot more than they can right now.

It would even give some nice things to vpilots, like getting rid of the TRO.

[*Rage*]

The point is the flight models are done by different teams (prob with some crosstalk though). As such which one do you take as the reference? If I remember correctly discrepancies between the flight models idiosyncrasies of the two aircraft were discussed on the russian side of the forum and the response from one of the ED developers was 'well it s a different team developing the F15'.

 

If I had to choose, i'd wager EDs implementation (yo-yo?) is the more comprehensive.

[GGTharos]

Neither can be taken as a reference for the other. They are developed independently - even if Yo-Yo was building both, he would have developed the FMs independently.

Edited June 4, 2015 by GGTharos

[Ktulu2]

The point is the flight models are done by different teams (prob with some crosstalk though). As such which one do you take as the reference? If I remember correctly discrepancies between the flight models idiosyncrasies of the two aircraft were discussed on the russian side of the forum and the response from one of the ED developers was 'well it s a different team developing the F15'.

 

100% agreed. You always want to make different mesurements in the same conditions, or by the same methods in science. ALTHOUGH I'd rather them do these planes fast-ish by giving one to do to a 3rd party than waiting 5 more years for the F-18.

[*Rage*]

Neither can be taken as a reference for the other. They are developed independently - even if Yo-Yo was building both, he would have developed the FMs independently.

 

Yes. But he would have developed them to an equal standard, since his standard is consistent within a given time period. Regardless of which particular FM he is developing. Different teams will have different standards (and capabilities) and might have different 'interpretations' of what they are tasked with/developing.

 

If you wanna talk science than you must only change one variable (ie the plane). If you change the developer as well than technically you can never be sure whether an observed difference in FM behaviour is due to the plane or the developer.

 

This is why I think its a great idea that BST is developing both the Mig15 and F86. Even if the flight model is not 100% (And i'm very happy with their efforts:thumbup:) at least you can be sure that the counterpart planes are developed to an equal standard.

[pepin1234]

For me Belsimtek and ED are mixed team. So now who have responsibility for the F-15 super-turn-fuel-tank-fight-climbing-increase-speed flight capable?

 

Nobody right? So they get their goal!