BFM technique questions for the Su27

[Tree_Beard]

Do you think the Su27 is generally better in a 1-circle fight or a 2-circle fight? 

If you are trying to go 2-circle, what airspeed do you want to aim for at the merge? (assume 10k feet ASL) 

What is the optimal corner speed for max turn rate at 5k, 10k and 15k ASL? 

How often do you override the flight control system? I am discovering that if I don't push that "cobra button" at the merge, I get smoked every time if the other bandit goes 1-circle unless I'm very slow at the merge. 

Is there anything specific to the Russian doctrine as opposed to the NATO doctrine that dictates how you are supposed to fight in this jet after the merge? 

General tips are also welcome. Thanks. 

[GGTharos]

18 hours ago, Tree_Beard said:

Do you think the Su27 is generally better in a 1-circle fight or a 2-circle fight?

Depends on what the bandit is doing.  There's no such things as 'better in a 1c or 2c', it always depends on what the bandit is doing and what your goal is:  Want to SHLEM some R-73's around?  You want range for this, so 2c.   Want most efficient BFM?  1c - but it all still depends on what the bandit is doing.

18 hours ago, Tree_Beard said:

If you are trying to go 2-circle, what airspeed do you want to aim for at the merge? (assume 10k feet ASL) 

Guess what ...

18 hours ago, Tree_Beard said:

What is the optimal corner speed for max turn rate at 5k, 10k and 15k ASL? 

Anything under M0.85 gives you full g's according to the gross weight schedule.

18 hours ago, Tree_Beard said:

How often do you override the flight control system? I am discovering that if I don't push that "cobra button" at the merge, I get smoked every time if the other bandit goes 1-circle unless I'm very slow at the merge. 

If you have to override it your BFM is most likely poor.   And you've hinted something about 1-circles here as well.

18 hours ago, Tree_Beard said:

Is there anything specific to the Russian doctrine as opposed to the NATO doctrine that dictates how you are supposed to fight in this jet after the merge? 

BFM doesn't care who you're flying for.   Aircraft differ in characteristics so 'all other things being equal', one can be better than another at some things.   But 'all other things' are rarely equal, so it still all depends on what your bandit is doing.

[Tree_Beard]

Since you seem like you know what you are talking about, can you help me understand what to pay attention to prior to the merge? Like how am I supposed to know what the bandit is trying to do as we fly straight at each other? Surely you have a general sense of what speed you want to be at to give yourself a chance to counter whatever he does after you merge? 

And the idea that there is no such thing as better in 1c vs 2c also confuses me... For example if it was a Hornet vs an F16, surely the F16 is going to try to force the hornet into 2c to play to its advantages, right? I'm thinking primarily about guns only, FYI. 

My knowledge of BFM obviously has a ways to go. 

[Glide]

The Su-27 flight model is the simple one, and it sort of cheats right now.  Best to practice against Mig-29s.  My favourite is to put 6 Reds with guns only with 5 or 6 Blues with guns only.  This gives you some time to get used to chasing them around.  I pack Sidewinders on these missions so I can practice getting the missile on their tails when they light up their ABs. 

Give this mission a try.  You can sub in the Su-27 if you like.

https://www.digitalcombatsimulator.com/en/files/3329069/

[GGTharos]

22 minutes ago, Glide said:

The Su-27 flight model is the simple one, and it sort of cheats right now. 

There's nothing 'simple' about the Su-27 flight model, it has some of the best modeled characteristics in game.

[MAXsenna]

There's nothing 'simple' about the Su-27 flight model, it has some of the best modeled characteristics in game.

Believe it was a reference to AI, because "against MiG-29's" were mentioned.

Sent from my MAR-LX1A using Tapatalk

[GGTharos]

1 hour ago, Tree_Beard said:

Since you seem like you know what you are talking about, can you help me understand what to pay attention to prior to the merge?

It's really too big a subject, but you're always looking to determine his speed (relative to yours), closure, and distance.   There are USAF/USN BFM manuals (I think the USN one is P-826?  I forget) which explain some of the basics, though I don't have the links handy.

For a start just decide if you want to do a 1c or 2c and make it happen - your choice depends on your bandit's speed and if you believe he can correctly counter your choice (likewise, you should also be prepared to counter correctly) as well as the weapon you wish to employ, or you wish him not to employ (if I'm in an eagle flying against you in a flanker, I'll be tempted to choose 1c to jam you R-73 since it would give you a huge advantage in 2c, or I would try to get a massive turn advantage at the merge).

The thing is, you need to learn some basic techniques and once you have some of those basics down, BFM comes down to prior planning.  The best people don't make it up on the go.  Ever move, change in speed etc is considered.  Techniques for bleeding speed, controlling AoA etc are determined, studied and adhered to.   So it's up to you to decide the level of BFM you wish to get yourself up to.  It's not an easy skill. 

1 hour ago, Tree_Beard said:

Like how am I supposed to know what the bandit is trying to do as we fly straight at each other? Surely you have a general sense of what speed you want to be at to give yourself a chance to counter whatever he does after you merge? 

You know what you want to do, so choose accordingly.  Don't overthink it, build your skills up step by step.

1 hour ago, Tree_Beard said:

And the idea that there is no such thing as better in 1c vs 2c also confuses me... For example if it was a Hornet vs an F16, surely the F16 is going to try to force the hornet into 2c to play to its advantages, right? I'm thinking primarily about guns only, FYI. 

If both have AIM-9X, 2c is potentially a mutual kill for everyone - bad tactics unless you have no choice, right? (I just realized you specified guns only)  Even if someone initiates a 1/2c, the other fighter can observe and change this.  If you miss your chance you can potentially still fix things but your window starts closing (may already be closed).   Regardless of 1/2c, you always want to merge with advantage if possible ... that means you've already eaten a chunk of angles when you pass your opponent (that's what a lead turn is typically for).

So here you have to decide 1c/2c what do I do if my opponent picks something else/is not at the parameters I thought he'd be at etc.

To answer your question more directly (And with exaggerated numbers), if you're in an F-16 and the opponent in an F-18, and that F-18 is doing 450kts, why would you not choose 1c?  1c is a min-radius fight and at slower speed you'll beat him.  You don't need to burn all your speed doing this either, just enough to determine you've won 1c, then start aligning.   He has options too, he could stay fast and try to come back around, and then you have to deal with that (which is why it's best to not burn all your speed if possible.  But the more he commits to beating you in that turn, the more you commit).

 

1 hour ago, Tree_Beard said:

My knowledge of BFM obviously has a ways to go. 

That's how it is.  But don't be discouraged, just keep in mind that this stuff builds up piece by piece.   You don't have the benefit of a BFM instructor like a real USAF/USN pilot would have so the learning curve tends to be longer and fraught with building bad habits, but that's game life

Take care to learn how to recognize target distance, aspect, speed and closure with your eyes in the BFM arena and you'll find life will become easier reasonably soon after that.  Yep, I mean recognize them without looking at the HuD.   And don't get too hung up on precice corner speeds etc - these things are useful, they're benchmarks, but they're not a BFM tactic, just a piece of useful data.

[Pavlin_33]

On 2/28/2023 at 9:51 PM, Tree_Beard said:

Do you think the Su27 is generally better in a 1-circle fight or a 2-circle fight? 

If you are trying to go 2-circle, what airspeed do you want to aim for at the merge? (assume 10k feet ASL) 

What is the optimal corner speed for max turn rate at 5k, 10k and 15k ASL? 

How often do you override the flight control system? I am discovering that if I don't push that "cobra button" at the merge, I get smoked every time if the other bandit goes 1-circle unless I'm very slow at the merge. 

Is there anything specific to the Russian doctrine as opposed to the NATO doctrine that dictates how you are supposed to fight in this jet after the merge? 

General tips are also welcome. Thanks. 

One and two circle fights depend on your and the state of your opponent and is mainly driven by geometry. I've created a simple illustrative example here:

You can determine the corner speed by your self. Simply speaking it's the highest G force you can pull at the lowest possible speed. Set a G limit for your self, let's say 9G and start pulling at let's say 1000km/h (full afterburner). The Flanker will start slowing down and the speed at which it can no longer pull 9G is just below the "corner" speed.

If we are talking about missile merges, USE THE OVERRIDE! This will allow you greater alpha and the only thing that matters there is to point your nose at the enemy and fire in the shortest time possible. If you get that R-73 at the enemy first, you do not really care about your airspeed nor your energy. He will be dead, and you can then go and recover. As one of the instructors said: "There's no use in dying with extra speed on your hands."

If we are talking about guns only DF, then I would say that the Flanker is quite poor in that arena. It's under-powered (compared to other DCS fighters) and personally I find that most I can do against competent adversaries is to push them in front of me, but then I can't do much 'cause they have the thrust advantage. If you come a cross similarly-skilled enemy there's not much you can do. MiG-29 is much better and F-15 is way better in guns-only dog fights.

Edited March 1, 2023 by Pavlin_33
Added guns-only comment.

[HwyStar]

I am a few of weeks behind the OP in knowledge, and this information, using the Su-27 is very helpful. Thanks for sharing all! I have had these same questions floating around in my head as I watch all of the YT videos out there. Good stuff Maynard!

[Top Jockey]

On 2/28/2023 at 8:51 PM, Tree_Beard said:

Do you think the Su27 is generally better in a 1-circle fight or a 2-circle fight? 

If you are trying to go 2-circle, what airspeed do you want to aim for at the merge? (assume 10k feet ASL) 

What is the optimal corner speed for max turn rate at 5k, 10k and 15k ASL? 

How often do you override the flight control system? I am discovering that if I don't push that "cobra button" at the merge, I get smoked every time if the other bandit goes 1-circle unless I'm very slow at the merge. 

Is there anything specific to the Russian doctrine as opposed to the NATO doctrine that dictates how you are supposed to fight in this jet after the merge? 

General tips are also welcome. Thanks. 

 

Hello,

What quantity ( percentage % ) of internal fuel are you starting with, at mission editor ?

Bear in mind that the Su-27 is a very big and heavy jet fighter, and also has a very big internal fuel capacity... which if at high percentage, equals to being VERY heavy and not that much suited to dogfight situations.

 

So, if you are only dogfighting, I would suggest you would start with:

- no more than roughly 30 % internal fuel

- full gun ammo

- 2 x R-73 Archer missiles

 

It's ACM capability specifics are also talked about on several threads, as example:

https://forum.dcs.world/topic/281302-thrust-to-weight-ratio-confused/page/6/

 

Good luck !

 

[TheFreshPrince]

Usually one circle is better in guns only, except against Mirage and probably Hornet. This applies if you have a dogfight mission setup against one bandit and a clean configuration. I recommend a lot of practice with that. The Flanker has very good turn performance at lower speeds, so you don't want to be too fast. Max 700kmh at merge, preferably a bit less. The max. rate speed for a two circle is somewhat around 650-700 iirc. 

 

After the merge, energy management is very important. You need to know when you can pull and cash it in, when to pull or push the burner, etc. This takes a lot of practice. There are a lot of videos about SU27 dogfights, just watch and copy and practice and learn.

[strelok2014]

В 01.03.2023 в 23:35, GGTharos сказал:

There's nothing 'simple' about the Su-27 flight model, it has some of the best modeled characteristics in game.

..and does not correspond to the documentation:

https://dcs.silver.ru/Diagram/Su27

In all FF models, slats and flaps improve the turn rate, on the Su-27 they worsen.
In addition, these "steps" at transonic speed looks very strange, no one else has them in the DCS.

PS:
The performance of the BFM is very dependent on the mass and depending on this, you need to use different tactics. Su-27 refueled by more than 60% is the same "sluggish" as the f-18 with additional fuel tanks.
If we conduct a more or less honest comparison of the sustainable turning rate, then with the same engine running time on the afterburner, the following data are obtained:
https://dcs.silver.ru/32-3730,135,144-1803,6-3010,120-4053,87-2187,148-1757,zoom,turnrate

Edited March 31, 2023 by strelok2014

[Mike_Romeo]

On 3/31/2023 at 8:38 AM, strelok2014 said:

..and does not correspond to the documentation:

Create a new thread in the bug forum.


Source: https://www.digitalcombatsimulator.com/en/support/faq/general/#1512209

Edited April 1, 2023 by Mike_Romeo

[strelok2014]

5 часов назад, Mike_Romeo сказал:

Create a new thread in the bug forum.


Source: https://www.digitalcombatsimulator.com/en/support/faq/general/#1512209

 

ED answered that they will no longer remake FC3 modules... Only FF.

[draconus]

1 hour ago, strelok2014 said:

ED answered that they will no longer remake FC3 modules... Only FF.

You suggested that the FM is wrong. Make a proper bug report, provide the docs and we'll see. They do fix the bugs in FC3.

[Mars Exulte]

On 3/1/2023 at 12:12 PM, Glide said:

The Su-27 flight model is the simple one, and it sort of cheats right now.  Best to practice against Mig-29s.  My favourite is to put 6 Reds with guns only with 5 or 6 Blues with guns only.  This gives you some time to get used to chasing them around.  I pack Sidewinders on these missions so I can practice getting the missile on their tails when they light up their ABs. 

Give this mission a try.  You can sub in the Su-27 if you like.

https://www.digitalcombatsimulator.com/en/files/3329069/

Incorrect. Exactly zero aircraft have simple flight models. All have PFMs or equivalents except the Su-25. Barring AI of course, they all use a simplified flight model.

On 3/1/2023 at 10:55 AM, Tree_Beard said:

Since you seem like you know what you are talking about, can you help me understand what to pay attention to prior to the merge?

 Relative closure rate, is he going much faster than you, maneuvering aggressively, off axis, climbing, descending, etc. These are all subtle clues as to what he's doing. There's no substitute for experience, and you will eventually learn to read the body language of the other aircraft.

On 3/1/2023 at 10:55 AM, Tree_Beard said:

And the idea that there is no such thing as better in 1c vs 2c also confuses me.

 A common mistake of noobs and youtubers is constantly using fancy bfm terms they heard online. These are indeed descriptive terms for various maneuver regimes and what have you, but you shouldn't be THINKING IN THOSE TERMS during a fight. On their own they don't mean much, as it's all subject to the moment, relative conditions of the fight, and skill levels of the respective pilots.

 You will generally play to your aircraft's strengths by trying to push things in a direction that favors you, for example a Bf-109 generally is lighter and has better climbrate than most other aircraft under equal conditions so climbing or fighting vertically is usually a preferred option, although not always necessary or ideal. Example a heavy P-47 comes in co-equal on speed and altitude you can simply climb straight up, he'll stall out first (provided he doesn't catch you with a snap shot) and you can drop on him from above while he's recovering energy. You won't ALWAYS do that, because it might not ALWAYS be wise at the moment.

 In the case of modern superfighters, they all have so much power and so much potential maneuverability, that the differences come down to a few percent one way or another. Helpful, yes, but usually not ''war winning'' on its own.

 Primary determinant is how the fight starts. If the other guy gets the drop on you, your 1c 2c stuff doesn't matter.

 Reading the situation. If he's in a very high energy state compared to you, running, climbing or diving won't be options. Turning into him will force him to either try a headon snapshot, aggressively maneuver shedding speed to try to get a shot (which may be able to exploit), or maybe he opts to shed speed by zooming up rolling on top of you and maintaining his energy potential and the initiative. In each of these choices there are possible options for you, meeting him head on, trying to encourage him to dump speed if it's favorable to you to do so, pulling him close if you want to try to force and overshoot, following him into the vertical (probably unwise if you have less energy or thrust but you can maybe try for a snapshot), and probably a variety of other things.

 The more skilled your opponent the fewer opportunities he'll give you and the fewer mistakes he'll make. A substantially better opponent may be near unbeatable, regardless of his aircraft, simply because he made no mistakes and you did, and that is USUALLY the thing that determines the fight, barring particularly unfortunate starting conditions.

 But there is no hard rule ''you must do this in this aircraft'' because while your aircraft may be superior in a certain category than another aircraft (or most) it may not ALWAYS be superior in ALL conditions against ALL aircraft, and ALL aircraft can fight in ALL regimes if the conditions are conducive.

 Experience will help you ''read the room'' as a fight begins, and will help you learn intuitively what the guy is doing (you can even recognise experience and quality of the other guys controls if he's unusually jerky, indecisive, wobbles oddly, etc). You won't always win the fights, regardless, but you'll gradually be able to last longer, or at least exploit those ''one shot'' mistakes the other guy makes, because everyone does. In equal fights, who screws up first loses, provided the other guy is a good marksman.

 On that note, practice basic gunnery a LOT, as I mentioned it comes down to exploiting tiny windows of opportunity that may or may not come again, it's essential you be able to kill efficiently or ''creating the opportunities'' won't do you any good.