correct as is F16 Still Underperforming

Gungho · May 16, 2023

2 hours ago, GGTharos said:

A real F-16 pilot who hasn't flown the jet for 10 years. He didn't say the bleed rate is garbage; he's also at 12000', so the speed will bleed. There's no magical 4th gen jet that will bleed speed nice and slow at that altitude.

That doesn't mean anything ...

Like come on yes it can and yes it does. It also doesn't say 'if I remember right', or 'disclaimer'.

Now, does anyone have energy bleed data for the Viper? I don't know (Although you can infer the bleed rate to some degree from the sustained and instantaneous graphs). But I do know that ED gets help from real operators to build the FM, so what is it about the youtube guys that you believe more than the guys ED asked to test the FM?

Finally, if it 'bleeds too much', how much should it bleed? How many g's for a 1kt/s bleed at a given altitude? How about a 5kt/s bleed?

If you watch the video at the end he does it at +-500ft agl. Not sure what his msl altitude is but it makes very little difference in the realm of possibility.

NineLine · May 16, 2023

14 hours ago, skywalker22 said:

Another proof1 and proof2 of under performing.

This is not proof, he stated he felt he had control issues that could have been part of the issue, as well we have reached out to him to discuss. If there are issues we are missing we will be happy to revisit, right now the F-16 is performing to the docs we have.

Furiz · May 16, 2023

47 minutes ago, NineLine said:

If there are issues we are missing we will be happy to revisit

I'd be happy if you revisit F-16 losing speed at mil power at high altitudes, with bags compared to hornet which gains speed in same settings. F-16 losing airspeed .trk

Also SOI logic from this thread:

DummyCatz · May 16, 2023

4 hours ago, GGTharos said:

Now, does anyone have energy bleed data for the Viper? I don't know (Although you can infer the bleed rate to some degree from the sustained and instantaneous graphs).

Bleed rate (dV/dt) can be used to calculate Specific Excess Power (Ps) to be compared with those in EM diagrams.

Ref Chapter 5. Altitude Change: Climb and Guide – Aerodynamics and Aircraft Performance, 3rd edition (vt.edu)

P_s = dh/dt + (V/g)(dV/dt)

Assuming no altitude loss, the equation can be rewritten into Ps = (V/g)(dV/dt), while Ps, g and V are in ft/s, and (dV/dt) in ft/s^2.

Edited May 16, 2023 by DummyCatz

BIGNEWY · May 16, 2023

threads merged

Bremspropeller · May 16, 2023

On 4/12/2023 at 6:27 PM, Minhal said:

Hence my request to review the stick behavior with its apparent deadzone.

Yes, please do that ED. Or just introduce a special options menu checkmark that makes people that don't have the force sensing hardware fly the jet and not PIO/ APC themselves all across the sky.

104th_Money · May 16, 2023

I'm a little late to the party here but just read through all the posts...

The DCS Viper currently has several issues that is affecting its performance...

First, the joystick. I have my warthog set to that maximum roll deflection is at about half of the roll axis of the stick. Pitch is a little more at about 3/4 of the pitch axis of the stick. It makes it very sensitive and took a bit to get used to but the quicker inputs to full deflection clearly give me an advantage against someone who does not.

Second, the performance or lack of concerning bleeding off speed and regaining energy. I don't need a chart to tell me that it is off, no I've never flown a Viper in real life and I take into consideration that former pilots on YT may have a slightly faded memory after awhile or have a difference of opinion based on their perceptions. Viper HUD videos also don't necessarily give you a certainty of which block they are flying as some models have better performance than others, although you can somewhat deduce that newer 4k videos are probably being flown in newer block jets.

That being said, I do believe that it bleeds off speed too quickly and does not regain energy as quickly in a rate fight. How can I be certain? Well, even a Viper driver that hasn't been in the cockpit for 10 years as GGTharos said, may not be able to remember the EXACT FEEL of the aircraft but he will definitely remember the hard numbers that were drilled into him about what airspeeds give what performance at a given fuel weight, weapons loadout, altitude and airspeed and what those numbers need to be when flying against a particular jet. So when they say, this is off quite a bit, that still compensates for the "feel" memory loss of the pilot. But numerous pilots have already been quoted saying that it is off. What we don't know is whether the SME's are able to give the exact performance information and in fact ED should make some of them available for discussion so we can hear their side of the story.

Another thing not to do with the Viper that people are griping about is that it can't beat the Hornet in DCS. That's because the Hornet is definitely overpowered and should not be able to rate like the Viper. Its strength is in its exceptional nose pointing ability at low speed which it gets from its fcs allowing it to pull way more AOA than the Viper, not its sustained turn rate. This is why you do not want to get into a slow speed phone booth fight in a Viper against the Hornet and the Hornet does not want to get into a rate fight with a Viper. I promise you will never hear a story from a real Hornet driver saying "I remember fighting this F-16 in a rate fight pulling 7.5G at corner while he was pulling 9g at his corner, we were on the spiral down toward the deck and I was just rating right around on him." The real Hornet bleeds energy like crazy and takes time to get it back, period. Its almost like they need to give swap certain parts of the flight models out between the 2 jets.

Third, the FCS is off in the Viper more than likely causing the lack of performance. I can say for certain that in CATIII mode, the roll rate is not reduced after 90 degrees of roll. It should give up to 324 degrees per second roll rate for the first 90 degrees of roll regardless of CATI or CATIII and at that point if it is in CATIII should reduce the roll rate by a certain percentage. Ours just keeps on spinning around. I certainly don't envy ED for having to model all of these things correctly with all the performance numbers matching up.

Fourth, the blackout model is not accurate. Why this hasn't been changed is beyond me. We have been knowing it is not accurate for a decade or more with no changes other than adding G warmups to the blackout model. And yes, you do know that if you pull max G with no G warm up (I believe its 10 seconds at above 5g?) you will black out much quicker in all planes. Of course the ability to pull G varies greatly between individuals and a pilot that can pull 9g for 30 plus seconds one day might not have gotten a good night of sleep, ate properly or had been going through something stressful that day or the day before would only pull 9g for 10-15 seconds or GLOC from rapid G onset quicker.

Knowing all of this, once G warmup has been accomplished we should be able to at least sustain 9g for 20 seconds to average it out. I have posted numerous times about the Lockheed Martin online magazine called Code One that had an excellent series on the F-16. Of course that was many years ago and certain things may or may not have changed since then but the author went into detail about pulling G and claimed he could hold 9G for 45 seconds and would be happy to prove it to anyone. Considering he was one of the test pilots of the early models, I would tend to give weight to his statement and call him a subject matter expert. Either that or ED needs to sell an addon that weighs you, takes a blood test and monitors your heart rate and blood pressure then uses those numbers to give you a variable G resistance every time you fly. Your triglyceride levels are too high, you ain't pulling much G today lol.

Fifth, as discussed in this topic already. People need to learn the complicated skill of dogfighting and all of the nuances that come with it. Learn to maintain corner speed but know when you need to be at a different speed. Use the vertical, out of plane maneuvering etc. It takes so much practice to recognize the energy states and sight pictures to know when to do what effectively.

MARLAN_ · May 16, 2023

3 hours ago, Furiz said:

I'd be happy if you revisit F-16 losing speed at mil power at high altitudes, with bags compared to hornet which gains speed in same settings. F-16 losing airspeed .trk

Also SOI logic from this thread:

The F-18 has more thrust than the F-16, so I don't think this is a problem. I don't know the exact math right now or anything like that to say how much the difference should be, but stating that the F-18 performs better with weight and altitude seems pretty expected to me.

FireNLD · May 16, 2023

31 minutes ago, MARLAN_ said:

The F-18 has more thrust than the F-16, so I don't think this is a problem. I don't know the exact math right now or anything like that to say how much the difference should be, but stating that the F-18 performs better with weight and altitude seems pretty expected to me.

Its not about thrust alone. Its about weight, drag, loadout, lift, etc. Going of engines alone the hornet has a ~5000lbs thrust advantage in both ab and mil. But it has to offset a GWT difference of around 1000lbs heavier. So there's more going on than just what you stated.

Edited May 16, 2023 by FireNLD

Furiz · May 16, 2023

Exactly not about thrust alone,

set our F-16 with 2 bags, 4 bombs at 30k alt , thrust at mil power and observe, should that really be happening?

Temetre · May 16, 2023

vor 37 Minuten schrieb FireNLD:

Its not about thrust alone. Its about weight, drag, loadout, lift, etc. Going of engines alone the hornet has a ~5000lbs thrust advantage in both ab and mil. But it has to offset a GWT difference of around 1000lbs heavier. So there's more going on than just what you stated.

The F-16 is a smaller and lighter plane, probably shape and center of mass optimized for light loads? The plane seems optimized for a very specific dogfighting regime.

At least logically, it seems to make sense that it suffers more from its aerodynamics/weight/CoM being thrown off by heavier loads. That up high, those tiny wings perform worse, and that the center of mass/instability being off is a bit of a problem. Causing inefficencies with AoA/flight surface position for stable flight. I remember hearing a Eurofighter could gain >10% range with thrust vectoring engines, just because engine thrust could line up better with the plane when cruising.

F-18 seems to have much wider wingspan and more body lift to rely on. Ive also heard the Hornets intake function better at high altitudes.

Also, do we even know the actual thrust depending on altitude, speed and including intake performance? People always cite some base numbers that dont really tell much about the situation.

Edited May 16, 2023 by Temetre

DummyCatz · May 16, 2023

1 hour ago, Blue Giant said:

How to calculate the Specific Excess Power (Ps) of F-16C at a certain time in DCS?

This is the best and only way to solve the discussion about energy bleed data.

Just like the comparison between STR and ITR in game and reality.

I'll share an example using the above equation P_s = dh/dt + (V/g)(dV/dt)

Given that the aircraft is bleeding its speed from 400 KTAS to 396 KTAS in a 1-sec time span, with a pretty constant bleed rate, and a tiny altitude loss of 5 ft. Then we can dial in all the elements we need:

dh = -5ft

dV = -4KTAS = -6.75ft/s

V = 398KTAS = 671.75ft/s (took the average)

g = 32.174ft/s^2

dt = 1s

The resulting Ps = -145.93 ft/s at the speed of 398KTAS.

Edited May 16, 2023 by DummyCatz

GGTharos · May 16, 2023

5 hours ago, 104th_Money said:

I don't need a chart to tell me that it is off

Yes, you do.

5 hours ago, 104th_Money said:

but he will definitely remember the hard numbers that were drilled into him

Again, no. Human memory sucks, it is very perishable. And yes it's certainly possible to retain details but your blanket statement is incorrect - you simply don't know if one has or has not retained this memory.

5 hours ago, 104th_Money said:

Another thing not to do with the Viper that people are griping about is that it can't beat the Hornet in DCS.

The hornet is irrelevant to this discussion.

5 hours ago, 104th_Money said:

Of course the ability to pull G varies greatly between individuals and a pilot that can pull 9g for 30 plus seconds one day might not have gotten a good night of sleep, ate properly or had been going through something stressful that day or the day before would only pull 9g for 10-15 seconds or GLOC from rapid G onset quicker.

Yes, all those things and more affect g-tolerance (for example, has the pilot practiced or trained their AGSM recently?), and one of the important functions of the g-warmup is for the pilot to figure out how well he'll be performing.

5 hours ago, 104th_Money said:

Knowing all of this, once G warmup has been accomplished we should be able to at least sustain 9g for 20 seconds to average it out.

Citation needed.

5 hours ago, 104th_Money said:

I would tend to give weight to his statement and call him a subject matter expert.

I would tend to give weight to real GLOC research instead and not one individual's account, who may well be very exceptional.

GGTharos · May 16, 2023

10 hours ago, skywalker22 said:

Like he doesn't have memories how it used to be, right? LOL

And he also tried the same thing at the deck, see my previous post. He sounds very convinced that the speed bleeding is way too fast.

@DummyCatzhas provided you with the math to at least begin to figure out if those statements are close to reality. I suggest you do the work.

okopanja · May 16, 2023

19 minutes ago, GGTharos said:

Again, no. Human memory sucks, it is very perishable. And yes it's certainly possible to retain details but your blanket statement is incorrect - you simply don't know if one has or has not retained this memory.

Best thing, that daddy f-16 pilot from the video appears to have problems figuring the optimal maneuvering toward target, but junior is respectful which counts as a plus.

GGTharos · May 16, 2023

Sure, it's been a minute for him probably - but the only point I want to make, is what should be well known at this point that if one wants ED to make changes, one must provide fairly solid data, not anecdotes. The goal isn't to impugn any member of the community or any current or ex-pilot, but rather to remind that people saying things doesn't go very far when actual data is available.

@Blue Giant and @DummyCatz have the right idea. If you want to show something's off, this is the way.

Edited May 16, 2023 by GGTharos

Temetre · May 16, 2023

vor 36 Minuten schrieb GGTharos:

Sure, it's been a minute for him probably - but the only point I want to make, is what should be well known at this point that if one wants ED to make changes, one must provide fairly solid data, not anecdotes.

Tbh its a bit tiring that we, the players, have to bring up factual data for things that so clearly seem wrong (g-force, not F-16 performance)? Thats the developers job, and the modules are so dang expensive after all.

I dont mind supporting development, but obvious issues like some of the G-force stuff (especially F-16) they should be able to figure out themselves, as soon as the issue is brought up. Preferably with a temporary "fix" till we get a more realistic simulation or they find better data.

Edited May 16, 2023 by Temetre

GGTharos · May 16, 2023

Don't bring data then, don't get any changes. It's literally that simple. Developers do a lot of complex work, yes, they can miss some stuff. If you want to bring it up, do it in a way that is difficult to question. The developers can't be going off checking stuff with every 'I don't feel this is right' comment, aerodynamics are tedious.

Same thing with the g-loc thing ... there are studies for this, and air force standards. So say it's 'obvious' all you like, but you have nothing to show for it so ... it's obvious based on what exactly?

If you find all of this tiring, maybe stop doing things that are tiring? Just be aware that the consequences of not backing up your feelings with solid facts is that your feelings are going to be very low on the 'let's check on this' priority list.

Edited May 16, 2023 by GGTharos

Temetre · May 16, 2023

vor 2 Stunden schrieb GGTharos:

Don't bring data then, don't get any changes. It's literally that simple. Developers do a lot of complex work, yes, they can miss some stuff. If you want to bring it up, do it in a way that is difficult to question. The developers can't be going off checking stuff with every 'I don't feel this is right' comment, aerodynamics are tedious.

Same thing with the g-loc thing ... there are studies for this, and air force standards. So say it's 'obvious' all you like, but you have nothing to show for it so ... it's obvious based on what exactly?

If you find all of this tiring, maybe stop doing things that are tiring? Just be aware that the consequences of not backing up your feelings with solid facts is that your feelings are going to be very low on the 'let's check on this' priority list.

So are you saying we can pay 80 bucks for a module, but shouldnt expect the dev to do good work, even cover the basics? It sounds like youre saying we should expect nothing from the devs. Which im sure you dont even think, but what you say just sounds kinda ridiculous like that.

Totally with you on F-16 underperformance, thats difficult to judge, but the G-force thing? Thats been talked to death anyway. People who know more than me have done so, over years, and only a while ago ED said theyre looking into it.

Edited May 16, 2023 by Temetre

GGTharos · May 16, 2023

14 minutes ago, Temetre said:

So are you saying we can pay 80 bucks for a module, but shouldnt expect the dev to do good work, even cover the basics?

On what basis do you say they don't do good work? Your feelings?

14 minutes ago, Temetre said:

It sounds like youre saying we should expect nothing from the devs. Which im sure you dont even think, but what you say just sounds kinda ridiculous like that.

You're straight up thinking ridiculous thoughts, basically all-or-nothing thinking.

14 minutes ago, Temetre said:

Totally with you on F-16 underperformance, thats difficult to judge, but the G-force thing? Thats been talked to death anyway. People who know more than me have done so, over years, and only a while ago ED said theyre looking into it.

Yep, then ED will look into it. I just think people are expecting more than they're going to get. Again, it won't be based on youtube videos or what people feel it should be. I'm not saying that those sources aren't useful starting points. What I am saying is that they are only starting points into an investigation, and you have to do a bit more than just repeat a mantra based on 'I think that'. You're immediately at a disadvantage because the devs have done their legwork, so you have to do yours and show they implented/heard wrong or you have received new data.

okopanja · May 16, 2023

29 minutes ago, Temetre said:

So are you saying we can pay 80 bucks for a module, but shouldnt expect the dev to do good work, even cover the basics? It sounds like youre saying we should expect nothing from the devs. Which im sure you dont even think, but what you say just sounds kinda ridiculous like that.

There exist on the market a product that court more to the players desires, however I would not call it realistic.

I may agree or disagree with some development choice, but this module belongs to the better supported modules. For those $80 bucks, you are getting more than any other choice outside from DCS, and when we talk about professional simulators, their prices outpace the DCS modules by several magnitudes.

As for the pilots just like any of us they also suffer from bias and memory tends to be a fragile thing. Just to illustrate: what would happen if you were to drive the car you drove 5 years ago? Would the feeling still be familiar to you or not? Would you be able to accelerate and break with confidence instantly or not?

On the other side charts provided that their a genuine and made without introducing measurement errors remain as solid proof. So find yourself a chart and try to replicate that performance. Demonstrate the deviation.

wilbur81 · May 16, 2023

Youtube search "F-16 Hud Demo" or the like and see what you come across, but I've never come across a single HUD video that had the Viper pilot (even in the nice thick air close to the ground, slick, in airshow demo configurations, or otherwise) pulling 9g's for more than a second or two...if at all. Even the slick-jet USAF Viper demos and the T-birds all include the "Big 9 G, tight radius turn" part of their displays... but any HUD footage I've ever seen of this "9G" 360deg turn is usually actually hovering between 6.5 and 7.5 G throughout most of the turn (see one example here and note, assuming he's in burner throughout the turn, how his airspeed seems to bleed throughout this not-really-nine-g-turn:

). This doesn't mean that they can't or don't, of course. I just suspect that the ubiquitous 9g monster jets and pilots aren't doing that stuff as much as is popularly claimed or believed. There's a thread entitled something like "9G sustained is not possible in the new F16 variants?" over at F-16.net might shed some light as well, but it does post charts that aren't acceptable in our forums, so I won't post links here.

Edited May 16, 2023 by wilbur81

skywalker22 · May 17, 2023

7 hours ago, wilbur81 said:

Youtube search "F-16 Hud Demo" or the like and see what you come across, but I've never come across a single HUD video that had the Viper pilot (even in the nice thick air close to the ground, slick, in airshow demo configurations, or otherwise) pulling 9g's for more than a second or two...if at all. Even the slick-jet USAF Viper demos and the T-birds all include the "Big 9 G, tight radius turn" part of their displays... but any HUD footage I've ever seen of this "9G" 360deg turn is usually actually hovering between 6.5 and 7.5 G throughout most of the turn (see one example here and note, assuming he's in burner throughout the turn, how his airspeed seems to bleed throughout this not-really-nine-g-turn.

This doesn't mean that they can't or don't, of course. I just suspect that the ubiquitous 9g monster jets and pilots aren't doing that stuff as much as is popularly claimed or believed. There's a thread entitled something like "9G sustained is not possible in the new F16 variants?" over at F-16.net might shed some light as well, but it does post charts that aren't acceptable in our forums, so I won't post links here.

Agreed, I also have never seen any footage of pulling 9g for over 2 or 3 seconds (except for the Gripen, which Mover reviewed, and he was surprised about pilot's and jet's capabilities), pulling +9g for 10 seconds and even on -2g. So based on that video, I doubt how many times in his life he had ever reached 9g.

darkman222 · May 17, 2023

As we had the discussion 100 times here. My 50 cents. As short as possible.

I understand what EM diagrams are for and that we need numbers to model the flight model after. But can you actually read out the energy bleed rate from them ? How is this being modelled? Yes, its a question. I am just a computer graphics artist and flight sim enthusiast. What I understand is that sustainable and instantaneous turn rate come from a combination of different values from the FM. But different combination of values can lead to the same turn rate performance. But everything else might be off. Also energy bleed behavior.

The mistrust people have is because there was a fix for the energy bleed behavior some time ago. And it lead to a difference of about 100 kts or more in a 180 degree turn. Which an undeniable big difference. Also that people found that Yaw and Pitch inertia values are swapped ( separate thread) does not build trust in the DCS F16 flight modelling. People will always do investigations.

If the bleed rate was still of and just hypothetical, if it would be improved, that would lead to an even more obvious problem with the g modelling.

Which leads to my second 50 cents.

Of course you cant measure human performance like aircraft performance. But if ( I dont have a proof for the F16 but I know for the german Eurofighter) the pilot needs to be able to sustain 15 seconds of 9G to be qualified to operate it, then why cant the virtual F16 pilot do so? It can not be stressed enough that all of the real F16 flight performance is built around the 9 G limit. Its more cruicial than on any other DCS aircraft.

The F18 vs F16 discussion is irrelevant, as long as the F18 in game is not 100% perfect FM wise. Whicht the FM of the F16 and the F18 never will. Then its a separate discussion for the F18 sub forums.

Edited May 17, 2023 by darkman222

skywalker22 · May 17, 2023

I did some test yesterday, will also upload the video I did from it.

So, circuling around @5000ft AGL, started with 2000lbs of fuel, no pylons installed: speed at 450knots, I could sustain 8-5G to 9G constantly. When fuel dropped under 500lbs, I could easily hold 9+ Gs.

Interesting is, when speed drops bellow 450 knots, Gs also drops (430=7,5G), if going faster, Gs rises (480=9,2+G). 450 is lets say, somehow the border that separates Gs.

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