F/A-18 vs F-16 Turn rate?

[oldtimesake]

15000 ft, 60% fuel, 2 amraams, 2 aim9s, F/A-18C-402's sustained rate of turn is 12.3deg/s (source from GAO report), while in DCS it is 13deg/s

[oldtimesake]

It is interesting that a lot of people who disable G-effect are always complaining that F-16 is too OP in rate fight:

Edited April 16, 2020 by oldtimesake

[Figaro9]

15000 ft, 60% fuel, 2 amraams, 2 aim9s, F/A-18C-402's sustained rate of turn is 12.3deg/s (source from GAO report), while in DCS it is 13deg/s

 

Hmmm, maybe you should do that test again... turn rate was tweaked a while ago, I get exactly 12.3 dgs. Hornet turn rate is right on known figures.

[oldtimesake]

@oldtimesake, careful with those images, you might get pegged for Rule 1.16.

 

So I suggest you save them when you still can:D:D

[Top Jockey]

Well look what i found (http://www.f-16.net/forum/viewtopic.php?f=30&t=53852). An F-16C with engine F110-GE-129 - aka Block 50.

 

...

 

If you load the F-16 to the exact same weight climb to same altitude, you get the same results.

 

So it seems the F-16 is correct, it's rather that the other figters are overperforming.

 

Thank you Youda for the clarifying.

 

Well, on that case it seems it might not be so easy to fix stuf, as being several aircraft it's less probable to get them all changed to 'correct' specs.

[Top Jockey]

This is probably the most indicated thread.

 

I've been trying the F-16 these days, so I'll post my impressions regarding what I felt about its performance in BFM.

 

I've been flying it against "the new kid on the block" the JF-17's A.I.

And I know it already: the A.I. flight model is not very realistic because of several reasons.

 

... the point is: I've also flown other types in similar conditions against the JF-17's A.I., and I noticed differences.

 

Essentialy my "experiment" consisted at:

- JF-17 (A.I.) : 2 x IR A-A missiles ; 3000 lbs internal fuel ; (pilot level 'excelent')

- F-16 and other types (flown by me) : 2 x IR A-A missiles ; 3000 lbs internal fuel

(or quantity for roughly the same amount of flight time as in the A.I. JF-17)

 

- tried mostly 2 circle fights, started at 3.000 ft altitude at the merge , in which the A.I. JF-17 also went for the vertical frequently;

- keeping my F-16 above 380 kts eventualy seemed to give me some advantage;

- but when needed to cash energy for angles (otherwise he would go into scissors or 1 circle), my speed dropped to near 300 kts... at which point the JF-17 starts gaining speed much quicker than my F-16, and thus giving him an higher Sustained Turn Rate than mine... and I can't follow him anymore.

 

And now you will all say: "Hey, but the in the A.I. pilot level 'excelent' the aircraft gains UFO like flight properties."

 

True, but when I've flown the above conditions in the F-15, F/A-18, Su-27 and even in the Mirage 2000, it was somewhat easier / faster to get on the JF-17's six o'clock and also easier to stay there.

Don't really know if it's supposed to be like this in real life, but it really is an anti-climax that way in the F-16.

[Hummingbird]

To stay OT I will say that the F/A-18C very much still outrates the F-16C in DCS when under the same load conditions, and not by a small amount either.

 

Interestingly the F/A-18 keeps this rate advantage all the way up to its G limiter, even when you use the override (been able to sustain 9.6 G's in it), i.e. the DCS F/A-18's rate somehow doesn't really fall off as you'd expect it to.

 

The only fighter than can currently beat a competently flown F/A-18C in a turn fight in DCS seems to be the F-14, and only if it forces the fight into one sustained around Mach 0.5-0.6.

[oldtimesake]

I think it has been tested before: the DCS F16 sustains less G than a real F16 at low speed.

 

The data may match at corner speed, but below that the DCS F16 is conservative.

 

https://postimg.cc/DSXf471f

Edited May 2, 2020 by oldtimesake

[oldtimesake]

check the loop starting around 7:21. The viper starts the loop with about 440 kts IAS and finishes the loop with almost the same speed. That is something that other jets lack in this game.

 

Disabling G effect will also help you exploit viper's advantage.

Edited May 2, 2020 by oldtimesake

[Top Jockey]

I think it has been tested before: the DCS F16 sustains less G than a real F16 at low speed.

 

The data may match at corner speed, but below that the DCS F16 is conservative.

 

https://postimg.cc/DSXf471f

 

I see, many people already have the same impression.

 

Do you believe that it might be because of the same reason, as Boeing asked ED not to feature the Hornet's flight model exactly as it is in real life ?

[oldtimesake]

I don't know, but there are tricks to compensate.

 

We note that those who excel at low speed maneuvering (JF17, F18, Su27...) deploy aft flaps automatically at low speed, while F15/16 don't. Try deploy it manually and you will turn better at low speed.

 

This won't solve the problem completely tho, because F18's FCS calculates the best deflection angle while you only have the option "full" or "zero" deflection.

Edited May 2, 2020 by oldtimesake

[Top Jockey]

I don't know, but there are tricks to compensate.

 

We note that those who excel at low speed maneuvering (JF17, F18, Su27...) deploy aft flaps automatically at low speed, while F15/16 don't. Try deploy it manually and you will turn better at low speed.

 

This won't solve the problem completely tho, because F18's FCS calculates the best deflection angle while you only have the option "full" or "zero" deflection.

 

I thought you were recomending that procedure for the F-16....

 

Eitherway, it is possible to beat the A.I. JF-17 in BFM in the conditions I mentioned before on the F-16.

 

It takes however, that one can't let being carried away into drop the speed too much in order to gain those last angles... because then the JF-17 will start its best sustained turn rate / energy fight, and the F-16 will take a lot of time to recover speed (and therefore its turning ability).

 

When steadily on his 6, I can stay there until the fuel is over.

(This being with roughly 3000 lbs of fuel, for both the JF-17 and my F-16.)

Edited May 2, 2020 by Top Jockey

[oldtimesake]

I had the same difficulties. Staying above 400 kts will give F16 advantages, but the final pull requires F16 to ditch energy otherwise it doen't have enough gun lead.

 

After numerous attempts, I finally figured out that if my shots missed, instead of continuing pulling hard to land shots, I should go vertical to store my energy and do a high Yo-Yo. Always wait for your opponent's mistake. Don't be greedy.

[oldtimesake]

I had the same difficulties. Staying above 400 kts will give F16 advantages, but the final pull requires F16 to ditch energy otherwise it doen't have enough gun lead.

 

After numerous attempts, I finally figured out that if my shots missed, instead of continuing pulling hard to land shots, I should go vertical to store my energy and do a high Yo-Yo. Always wait for your opponent's mistake. Don't be greedy.

[Top Jockey]

I had the same difficulties. Staying above 400 kts will give F16 advantages, but the final pull requires F16 to ditch energy otherwise it doen't have enough gun lead.

 

After numerous attempts, I finally figured out that if my shots missed, instead of continuing pulling hard to land shots, I should go vertical to store my energy and do a high Yo-Yo. Always wait for your opponent's mistake. Don't be greedy.

 

In my case, the final pull is the one to close the remaining Anlge-off, to get steadily on his 6... otherwise I'll start to overshot him and he'll start a 1 circle fight.

 

(The lead pull you mention for the gun solution, usually only requires a little and brief pull and the lost speed is easily recoverable; because prior to that our Angle-off was very small already...)

[oldtimesake]

In my case as soon as a jet wants to initiate a 1 circle with me (in the viper), I will roll 180 deg and transit to 2 circle immediately.

[darkman222]

.... and you still gonna lose 2 circle. Why? Because the F18 going nose high whips around for 5 seconds with a peak of up to 25 degrees / sec.

Nothing to blame the F18 pilot for. No paddle used, no over G. Seems all legit what he did. Except the turn rate the F18 gave him. At least to me it does.

 

Then clever people tell you to go uphill and stay fast... and get hit by the F18 again with 24 degree /second @ 6.8 G. Every time the Hornet gets some of those in credible turnrate peaks for some seconds you lose more and more in the rate fight.

 

I'm not qualified to judge. I am just a gamer. But fingers crossed that the sustained G and drag model fixes that are anounced for the F16 will help to get the annoying wasp off your 6.

 

I guess this thread will get back to life after that update.

 

Edited April 9, 2021 by darkman222

[SpaceMonkey037]

17 minutes ago, darkman222 said:

.... and you still gonna lose 2 circle. Why? Because the F18 going nose high whips around for 5 seconds with a peak of up to 25 degrees / sec.

Nothing to blame the F18 pilot for. No paddle used, no over G. Seems all legit what he did. Except the turn rate the F18 gave him. At least to me it does.

 

Then clever people tell you to go uphill and stay fast... and get hit by the F18 again with 24 degree /second @ 6.8 G. Every time the Hornet gets some of those in credible turnrate peaks for some seconds you lose more and more in the rate fight.

 

I'm not qualified to judge. I am just a gamer. But fingers crossed that the sustained G and drag model fixes that are anounced for the F16 will help to get the annoying wasp off your 6.

 

I guess this thread will get back to life after that update.

 

 

You're way low on speed. The F-16's optimum turn rate speed in MAX AB is as fast as possible sustained level flight without blacking out. Takes a bit of getting used to but I think a speed of 460-480 should be a good place to start before you really find the limit. I really don't understand why you're going vertical, it's better to limit the hornet's vertical airspace by getting down low where his escape routes are limited to going up instead of down. Will increase chance of a kill.

[Xavven]

1 hour ago, darkman222 said:

 But fingers crossed that the sustained G and drag model fixes that are anounced for the F16 will help

 

 

 

Ooo... this sounds nice. Where is this posted? Are we getting performance improvements for the F-16?

[Noctrach]

1 hour ago, SpaceMonkey037 said:

You're way low on speed. The F-16's optimum turn rate speed in MAX AB is as fast as possible sustained level flight without blacking out. Takes a bit of getting used to but I think a speed of 460-480 should be a good place to start before you really find the limit. I really don't understand why you're going vertical, it's better to limit the hornet's vertical airspace by getting down low where his escape routes are limited to going up instead of down. Will increase chance of a kill.

Massive overstatement that the real life manual disagrees with. 380-400 KCAS is right in in the middle of the F-16's rate band.

 

The Viper has a huge Ps0 corner plateau that only drops 2 degrees between 0.8 all the way down to 0.54 IMN at 5000 feet.

At 15,000 feet, the Ps0 curve is perfectly flat between 0.88 IMN (450 KCAS) and 0.7 (350 KCAS).

At sea level the Ps0 curve peaks at 0.59 IMN (390 KCAS), dropping off 1 whole degree down to 0.4 and 1 degree down to 0.8.

Meanwhile the quickest instantaneous turn rate possible is 24.1 deg/s 8G at 0.54 IMN (360 KCAS) at a MASSIVE energy bleed of -850 specific excess power, sea level obviously.

 

That means for best performance you enter the merge with a nose-low, 9G slice at 450-460 KCAS and bleed down to your rate band at 390-420 for optimal performance.

 

This aircraft was literally built to rate over a very broad speed-range.

The Hornet was built to have extremely high AoA spikes, meaning a single enormous rate pull at the cost of a lot of speed.

The E-M snippets I've seen also reflect this. The Viper's is a plateau, the Hornet's is a peak.

The vertical should be the Viper's playground with its supreme thrust to weight, the slow horizontal is the Hornet's.

 

The fact that it rates better at whatever altitude that fight was than the F-16CJ block 50's absolute fastest instantaneous sea level, without absolutely hemorrhaging knots, should tell you enough about the state of either jet's current drag model.

 

At the end of the day we're fighting F-16DCS vs F/A-18DCS so use appriopriate tactics to the state of the game.

Currently that means blowing through the merge at extreme speeds and taking things vertical, there's no gameplan to be had in the horizontal against a competent Hornet driver.

[jaguara5]

There are also some FM changes coming for the Hornet.  Have asked this over at reddit 

[SpaceMonkey037]

12 hours ago, Noctrach said:

Massive overstatement that the real life manual disagrees with. 380-400 KCAS is right in in the middle of the F-16's rate band.

 

The Viper has a huge Ps0 corner plateau that only drops 2 degrees between 0.8 all the way down to 0.54 IMN at 5000 feet.

At 15,000 feet, the Ps0 curve is perfectly flat between 0.88 IMN (450 KCAS) and 0.7 (350 KCAS).

At sea level the Ps0 curve peaks at 0.59 IMN (390 KCAS), dropping off 1 whole degree down to 0.4 and 1 degree down to 0.8.

Meanwhile the quickest instantaneous turn rate possible is 24.1 deg/s 8G at 0.54 IMN (360 KCAS) at a MASSIVE energy bleed of -850 specific excess power, sea level obviously.

 

That means for best performance you enter the merge with a nose-low, 9G slice at 450-460 KCAS and bleed down to your rate band at 390-420 for optimal performance.

 

This aircraft was literally built to rate over a very broad speed-range.

The Hornet was built to have extremely high AoA spikes, meaning a single enormous rate pull at the cost of a lot of speed.

The E-M snippets I've seen also reflect this. The Viper's is a plateau, the Hornet's is a peak.

The vertical should be the Viper's playground with its supreme thrust to weight, the slow horizontal is the Hornet's.

 

The fact that it rates better at whatever altitude that fight was than the F-16CJ block 50's absolute fastest instantaneous sea level, without absolutely hemorrhaging knots, should tell you enough about the state of either jet's current drag model.

 

At the end of the day we're fighting F-16DCS vs F/A-18DCS so use appriopriate tactics to the state of the game.

Currently that means blowing through the merge at extreme speeds and taking things vertical, there's no gameplan to be had in the horizontal against a competent Hornet driver.

Are you sure you're looking at the correct engine and MAX AB instead of MIL? Because I am quite positive I'm not blind and at 15k feet the turn rate curve for Ps0 is far from flat. And the sea level Ps0 peak is at mach 0.7, not 0.59 like you say. And if that isn't enough it convince you that you have the wrong data, the quickest possible turn rate at sea level is 24.9 deg/s, not 24.1 as you say.

Don't get me wrong, it's impossible to make a perfect flight model. If you're testing with incorrect data it should be no surprise that you're finding mistakes in our F-16 FM. So please use the correct FM data when making your conclusion about the DCS F-16's FM.

Edited April 10, 2021 by SpaceMonkey037

[Noctrach]

1 hour ago, SpaceMonkey037 said:

Are you sure you're looking at the correct engine and MAX AB instead of MIL? Because I am quite positive I'm not blind and at 15k feet the turn rate curve for Ps0 is far from flat. And the sea level Ps0 peak is at mach 0.7, not 0.59 like you say.

Don't get me wrong, it's impossible to make a perfect flight model. If you're testing with incorrect data it should be no surprise that you're finding mistakes in our F-16 FM. So please use the correct FM data when making your conclusion about the DCS F-16's FM.

 

 

I was indeed looking at the MIL charts, but the point stands... the thrust does not change the handling characteristics or FLCS laws of the aircraft.

 

For 15,000 feet max AB, your best performance is between 400-450 KCAS (0.78-0.88 IMN) with about 0.5 deg/s variance. Go down to 350 KCAS and you drop another 0.8 deg/s. So more than 100 KCAS speed loss results in a 1.3 deg/s reduction in turn rate.

Meanwhile exceeding 0.88 IMN and it drops off sharply at about 0.7 degrees per 0.02 IMN.

 

At sea level we see a similar story, peak sustained at 0.7 IMN/460 KCAS, peak instantaneous at 0.54 IMN/360 KCAS.

Above 460 KCAS and you run into the 9G limiter, meaning you will have to ease off of the throttle.

 

What a surprise, those are almost the exact same results as in MIL, except the Ps0 line has moved up.

I'll repeat my response to your comment about him being "way low on speed" at 390-400 KCAS: he's not, anywhere between 350 and 450 is a good speed to be flying that gives a lot of tactical options. It's not peak sustained for a perfectly level horizontal turn, but that's for deck-groveling-BFM. You're looking at the highest point on the Ps0 line and going "Yep, that's it right there! Faster is gooder" which is not a good BFM gameplan.

 

Besides, the Viper's turn capabilities are pretty much accurate with the docs for the 5% error margins I expect in a sim. Especially on an EA module.

Personally, I think people who are obsessed with 1-2 deg/s differences are making too big a deal out of it. Both pilots need to be flying a perfectly level rate fight for multiple minutes for that to decide the outcome. It's a huge DCS-ism that relies on high aspect 1v1 gunzo BFM until bingo being the name of the game. Normally the Viper could just run or reset at any time.

 

With regards to the FM, the way I see it, there's a couple of facts:

1. The Viper's FM underperforms in induced drag and energy bleed rates, especially at speeds below 350 KCAS (you know, the speeds you will end up when you do an instantaneous rate excursion). Meaning you can max perform exactly once and then you struggle putting the knots back on. This has been confirmed by ED and will likely change in the future.
2. The Hornet's FM might overperform in induced drag and energy bleed rates. We have no hard data so who knows, all we know is the FM is being re-evaluated for release.
3. The Hornet's FM might overperform in turn rate. We have no clue because again there's no docs so we're just gonna have to assume DCS is correct.
4. Stores drag in DCS follows no reasonable logic. (Double racks incurring less drag than single racks, jettisoned ordnance reducing drag below clean numbers, etc.)

We have a combination of Viper docs, multiple corroborating pilot accounts, aerodynamic shape and a known, universal DCS FM deficiency hinting at the fact the problem is probably in the drag model. I'd say it's a pretty safe bet.

 

The Viper is a thrust-to-weight 9G machine. It excels at doing short energy excursions and then getting those knots back with its massive engine. If it's too draggy to do that compared to its slow-speed AoA-monster opponent, then you simply don't have much to work with.

Edited April 10, 2021 by Noctrach

[SpaceMonkey037]

5 minutes ago, Noctrach said:

 

I was indeed looking at the MIL charts, but the point stands... the thrust does not change the handling characteristics or FLCS laws of the aircraft.

 

For 15,000 feet max AB, your best performance is between 400-450 KCAS (0.78-0.88 IMN) with about 0.5 deg/s variance. Go down to 350 KCAS and you drop another 0.8 deg/s. So more than 100 KCAS speed loss results in a 1.3 deg/s reduction in turn rate.

Meanwhile exceeding 0.88 IMN and it drops off sharply at about 0.7 degrees per 0.02 IMN.

 

At sea level we see a similar story, peak sustained at 0.7 IMN/460 KCAS, peak instantaneous at 0.54 IMN/360 KCAS.

Above 460 KCAS and you run into the 9G limiter, meaning you will have to ease off of the throttle.

 

What a surprise, those are almost the exact same results as in MIL, except the Ps0 line has moved up.

I'll repeat my response to your comment about him being "way low on speed" at 390-400 KCAS: he's not, it's a very good speed to be flying that gives him a lot of tactical options. It's not peak sustained for a perfectly level horizontal turn, but that's for deck-groveling-BFM.

You're looking at the highest point on the Ps0 line and going "Yep, that's it right there! Faster is gooder" which is not a good BFM gameplan.

 

Besides, the Viper's turn capabilities are pretty much accurate with the docs for the 5% error margins I expect in a sim. Especially on an EA module.

Personally, I think people who are obsessed with 1-2 deg/s differences are making too big a deal out of it. Both pilots need to be flying a perfectly level rate fight for multiple minutes for that to decide the outcome.

 

With regards to the FM, the way I see it, there's a couple of facts:

1. The Viper's FM underperforms in induced drag and energy bleed rates, especially at speeds below 350 KCAS (you know, the speeds you will end up when you do an instantaneous rate excursion). Meaning you can max perform exactly once and then you struggle putting the knots back on. This has been confirmed by ED and will likely change in the future.
2. The Hornet's FM might overperform in induced drag and energy bleed rates. We have no hard data so who knows, all we know is the FM is being re-evaluated for release.
3. The Hornet's FM might overperform in turn rate. We have no clue because again there's no docs so we're just gonna have to assume DCS is correct.
4. Stores drag in DCS follows no reasonable logic. (Double racks incurring less drag than single racks, jettisoned ordnance reducing drag below clean numbers, etc.)

We have a combination of Viper docs, multiple corroborating pilot accounts, aerodynamic shape and a known, universal DCS FM deficiency hinting at the fact the problem is probably in the drag model. I'd say it's a pretty safe bet.

 

The Viper is a thrust-to-weight 9G machine. It excels at doing short energy excursions and then getting those knots back with its massive engine. If it's too draggy to do that compared to its slow-speed AoA-monster opponent, then you simply don't have much to work with.

 

What engine is the chart you're looking at for? The data you're supplying is still incorrect for the F110-GE-129 engine at MAX AB.

Edited April 10, 2021 by SpaceMonkey037

[Noctrach]

1 hour ago, SpaceMonkey037 said:

What engine is the chart you're looking at for?

F110-GE-129

Edited April 10, 2021 by Noctrach