PSA: F-14 Performance/FM Development Status + Guided Discussion

[Katj]

The wounded victim look is unbecoming.

What's with all the ad hominem coming from you? It's unbecoming, too.

If you're going to hold people to such high standards with regards to the scientific method then please elevate yourself to that level as well.

[captain_dalan]

 

 

1 hour ago, Hummingbird said:

@captain_dalan I now think I know how you got the results you did, it turns out the script WILL actually log a rate whilst you're losing alt, so not true Ps=0 . You can see it in the video below where I use your mission, notice that during some of the script's recordings altitude is actually decreasing as the script logs the rate. 

 

I also once again manage to get the aircraft very stable at M 0.46, and get a good long stream grabs starting at 03:14 min. Also note the infobar and the G reading it is registering = 4.6-4.7 G throughout:

 

And the logfile with the recordings so you can compare with the video:

So according to the script an average of 16.8 dps @ M 0.46 =  4.75 G.  Whilst the actual infobar reads 4.6-4.7 G throughout that turn.

 

Compare this with my last result (it's the same):

 

 

 

I'm trying to replay again, something must have went wrong the first time. 
It looks like for some reason you are flying at a slightly  higher angle of attack. Are you adding enough rudder to your turns? If so, then something else must wrong with your technique. This are my results (i just flew them) and how i got them:
 

Mach 0.463 or 306 knots, 4.96g. That's practically right on the money 

Edited November 6, 2021 by captain_dalan

[Baz000]

Listen guys, all is well... The sky is blue and the grass is green, and the MiGs are red.

I returned with a rabbit from my funny farm today and I "offered it" upon the altar of Goose, which is a replica of the canopy that I had erected in honor of the F-14 airframe that was lost during the filming of "that dumb movie." Too soon?

I did this act so we can bring the thread back to its point of equilibrium, much like trying to fly at a trimmed state and hitting turbulence and coming back to smooth air.

So, guys we hit some turbulent air and now we are out and it is clear skies ahead... Don't make me start breaking out the naval jargon 

[Hummingbird]

I can't explain the difference between our results @captain_dalan, scratching my head here... the turns are coordinated, I'm holding them rock steady. I can't for the life of me hit above 4.7 G @ M 0.46 under the chart conditions (sea level, 15 C, 55,620 lbs, 4x4 etc), and managing the 5 G chart value is totally impossible for me.

I'm going to do a repair of DCS when I get back to my desktop tomorrow, I think you should do the same, just to rule anything out in that regard.

Should note I in the same session also tested again at M 0.62 (410 KTAS), and here as before I'm again hitting 6.5 G spot on, just as on the charts, and at M 0.34 I'm getting 3.2 G (+0.2 G vs 3 G chart values)

 

Btw, earlier today when I flew the A my slats/flaps weren't working below ~340 kts and above 15 units AoA, only in the A though, they work flawlessly in the B. Is it possible you could check yours here?

Edited November 6, 2021 by Hummingbird

[Victory205]

7 hours ago, Katj said:

What's with all the ad hominem coming from you? It's unbecoming, too.

If you're going to hold people to such high standards with regards to the scientific method then please elevate yourself to that level as well.

Ad hominem my arse, that‘s exactly what was happening. After months of disruptive posts, ignoring advice on best practices that will produce usable data, and being emotionally invested in his outcomes, we get a poor pitiful me response. The goal is getting accurate information by performing a simple task correctly. There should be zero drama in an analytical task without all of the nonsense. 

You notice that the gents who are interested in performance are finally beginning to show their work and at provide some their test parameters and methods. Still managing to leave us in the dark on a few inputs, but there is hope that we’ll end up with useful information. Maybe someday, they’ll move up to the EM Chart altitudes.

If I am wrong about the way I approach a task, or am using an improper technique or have an inaccurate setup, or am stuck on stupid myself in any way, then I want to be told about it so it can be corrected. Valid performance should always produce repeatable outcomes. 

Don’t forget, the context of all of this is occurring when we know that the performance modeling is not finished. 

Edited November 6, 2021 by Victory205

[Katj]

The goal is getting accurate information by performing a simple task correctly. There should be zero drama in an analytical task without all of the nonsense.

I agree completely. So let's get back to the zero drama discussion!

You notice that the gents who are interested in performance are finally beginning to show their work and at provide some their test parameters and methods. Still managing to leave us in the dark on a few inputs, but there is hope that we’ll end up with useful information. Maybe someday, they’ll move up to the EM Chart altitudes.

Yes, they are, and I very much appreciate seeing the progress that's being made on the performance side of the flight model. There's obviously good work being done on several aspects of the FM.

Unfortunately I can't really claim to have noticed that Heatblur is being very transparent on their methodology, though. There might be valid reasons for this, or maybe I just missed it. Anyway, all I've heard is "we have better methods of testing".

Fat Creason promised us test data down the line, so I'm looking forward to that.

[Victory205]

The results will be obvious, since everyone will be able to see for themselves.

It‘s not my call to divulge methodology, but I‘m confident that it will produce solid results. It just takes enormous time by people who have other jobs and families.

[Hummingbird]

Already tested at 5 kft (I wonder when you will finally notice) and found performance there was in order. No reason to focus on an area where numbers are matching, precisely because the goal here isn't to be "disruptive".

We've got 4 perfectly valid performance references for sea level we're now focusing on, where the F-14 is currently possibly not matching in 2 of them.

 

[Snappy]

2 hours ago, Hummingbird said:

Already tested at 5 kft (I wonder when you will finally notice) and found performance there was in order. No reason to focus on an area where numbers are matching, precisely because the goal here isn't to be "disruptive".

We've got 4 perfectly valid performance references for sea level we're now focusing on, where the F-14 is currently possibly not matching in 2 of them.

 

Don’t confuse “we” with “you”.  You really can’t let it go , can you?  Why don’t you simply wait until performance has been adjusted across the altitudes,  as fat creason announced he would work through them with time? Like he said, there is no point in testing at the moment . I get your deep interest in performance, but how about simply stepping back for the moment or doing your thing without announcing results on these forums.

Edited November 6, 2021 by Snappy

[sparrow88]

12 hours ago, captain_dalan said:

 

 

I'm trying to replay again, something must have went wrong the first time. 
It looks like for some reason you are flying at a slightly  higher angle of attack. Are you adding enough rudder to your turns? If so, then something else must wrong with your technique. This are my results (i just flew them) and how i got them:
 

Mach 0.463 or 306 knots, 4.96g. That's practically right on the money 

 

Is this mission available somewhere to download? I would gladly perform some tests too. Also it seems like a nice tool for practicing coordinated turns

 

[Hummingbird]

15 minutes ago, Snappy said:

Don’t confuse “we” with “you”.  You really can’t let it go , can you?  Why don’t you simply wait until performance has been adjusted across the altitudes,  as fat creason announced he would work through them with time? Like he said, there is no point in testing at the moment . I get your deep interest in performance, but how about simply stepping back for the moment or doing your thing without announcing results on these forums.

I'm not the only one, we're quite a few people testing this atm.  Also I get performance isn't final and I'm not posting to complain, like I've said many times before, I'm posting the findings to keep track of changes, and to inform where to possibly expect improvements.

As for "letting it go", with all due respect I think that sentence more appropiately applies to the people who for some reason can't cope with others posting some figures on a screen and feel the need to start barking at them.

7 minutes ago, sparrow88 said:

Is this mission available somewhere to download? I would gladly perform some tests too. Also it seems like a nice tool for practicing coordinated turns

 

I'm sure Cpt. Dalan would have no problem PM'ing you the mission  And yes please, the more testers the better. Just remember to test a lot of times at the same target speeds & alts before drawing any conclusions.

Edited November 6, 2021 by Hummingbird

[Victory205]

1 hour ago, Snappy said:

Don’t confuse “we” with “you”.  You really can’t let it go , can you?  Why don’t you simply wait until performance has been adjusted across the altitudes,  as fat creason announced he would work through them with time? Like he said, there is no point in testing at the moment . I get your deep interest in performance, but how about simply stepping back for the moment or doing your thing without announcing results on these forums.

 

The SL “performance” isn’t valid, he won’t let go of that, which speaks volumes, nor have I seen the information from valid altitudes and configurations proven, although it’s possible that I missed it. 

It’s possible to reduce a SL estimate from the precise EM charts (that are constructed specifically to show turn performance) mathematically, but I guess they don’t know how. It takes a little work.
 

[Baz000]

Look guys, you have a former real life verified not virtual squadron F-14 pilot telling you the data points you are using to derive your information regarding performance characteristics at SL is flat out invalid. I'm sure he is understanding your testing methodology and how you are arriving at your conclusions. The fact of the matter seems to be that the baseline performance charts/statistics you are using are mathematically derived anomalies, amalgamations of engineers with slide rules... Not actual flight test data of performance.

This reminds me of a scene in "that dumb movie" where Maverick and Goose seem to think they got a "valid" kill on Jester, they are so cocky about it that they then do a fly-by of the tower in that ubiquitous coffee spilling scene.

A scene that isn't played too often is them getting spoken to by the CO about breaking the "hard-deck" which is there to simulate the GROUND (ground mort, because actually flying into the real ground would be very very bad!) in ACM. So, the CO is there asking him "Why did you decide to follow Jester and also fly into the ground?"

I'm sure they are stunned to be asked such because they are so focused on the objective of killing Jester in that hop that they completely disregard the established safety rules. But, they don't react in condemnation or engage in some sort of logical fallacy of an argument of "yeah, but we killed Jester! MAN!"... Yeah? But you fools chased him into the ground and flew into the ground yourselves...

I present for you the two scenes for your viewing scrutiny and entertainment.

 

 

Look at the disparity between the two clips and understand what Victory205 is telling us. And if you don't understand him, maybe ask him kindly if he could clarify maybe something you don't understand entirely or if he could explain something in a way you can understand, maybe use different terms more familiar to a layman, etc...

Edited November 6, 2021 by Baz000

[Hummingbird]

1 hour ago, Victory205 said:

The SL “performance” isn’t valid, he won’t let go of that, which speaks volumes, nor have I seen the information from valid altitudes and configurations proven, although it’s possible that I missed it.

 

I've posted the 5 kft data at the valid configurations already twice. We've currently only been testing STR at 55,620 lbs, 4x4 config.

 

Anyway, the SL performance certainly is valid, we have Ps=0 estimates for it at four different load factors (1, 3, 5 & 6.5 G) in the specific excess power (H-M) charts. To prove they're valid, you can cross reference them with the EM & VN charts at all the altitudes, and you'll see they all match perfectly with the H-M chart.

To prove the point, let's compare the EM vs HM vs VN charts at 5 kft:

Spoiler

 

They all perfectly match, and it's the same story for which ever altitude you choose. Hence there is no reason to believe the HM charts aren't  accurate for SL as well. It's clear that SL performance is mathematically deduced, that's not in contention, however its been deduced by the pro's in the field with the tools necessary to get figures as close to real life as mathematically possible, hence we logically need to use this as our reference as we simply don't, and won't ever, have any more accurate data available.

 

In short could the SL figures be slightly inaccurate? Sure, but IMHO we simply have no choice but to use them as our target, as they are the best we are ever going to get. I myself calculated SL performance to be 6.7 G @ M 0.62, not 6.5 G as on the HM chart, but I have to bow to the better ability of the professional aero engineers to mathematically deduce such things.

Edited November 6, 2021 by Hummingbird

[Hummingbird]

46 minutes ago, Baz000 said:

Look guys, you have a former real life verified not virtual squadron F-14 pilot telling you the data points you are using to derive your information regarding performance characteristics at SL is flat out invalid.

So it's by magic that the EM, VN & HM charts all perfectly match at every single altitude?

[Slant]

Hmm, seen a lot of bickering over methodology... but what is it we're talking about specifically? Sorry, jumping in the middle of the discussion here, but I want to see why these heavy blows are being dealt.

 

Also, is it worth all these tears when HB says they're not done, yet? Or is this the time to bring up issues about performance?

[captain_dalan]

4 hours ago, sparrow88 said:

Is this mission available somewhere to download? I would gladly perform some tests too. Also it seems like a nice tool for practicing coordinated turns

 

PM-d you

[captain_dalan]

1 hour ago, Slant said:

Hmm, seen a lot of bickering over methodology... but what is it we're talking about specifically? Sorry, jumping in the middle of the discussion here, but I want to see why these heavy blows are being dealt.

 

Also, is it worth all these tears when HB says they're not done, yet? Or is this the time to bring up issues about performance?

Mostly ego clashes.  
And certainly not worth the bother. For one the FM isn't final and also the differences are minuscule if any. Certainly beyond the threshold of detection except for the most die hard of fans to look for them. And even then, when compared with the accuracy of the chart, they could easily be attributed to statistical variation. 

[Baz000]

2 hours ago, Hummingbird said:

So it's by magic that the EM, VN & HM charts all perfectly match at every single altitude?

Do you believe in Magick?  

Edited November 6, 2021 by Baz000

[Hummingbird]

I think the reason some people (incl. myself) are so passionate about subjects such as these, are that in our minds there are few worse feelings than lacking/having a performance advantage you know should've/shouldn't have. Which is why getting all the modules matching the charts as close as possible is one of our greatest desires. 

For example right now it pains me that the F15 FM is suddenly broken, and it will kick the butt of the F16 in many cases where it shouldn't. Or the AV8B basically lacking lift induced drag and being able to outturn every single jet figher in the game atm... 

Edited November 6, 2021 by Hummingbird

[lunaticfringe]

2 hours ago, Hummingbird said:

So it's by magic that the EM, VN & HM charts all perfectly match at every single altitude?

Charts constructed using the same interpolated data set match.

Earth shattering, I know.

[Baz000]

17 minutes ago, Hummingbird said:

I think the reason some people (incl. myself) are so passionate about subjects such as these, are that in our minds there are few worse feelings than lacking/having a performance advantage you know should've/shouldn't have. Which is why getting all the modules matching the charts as close as possible is one of our greatest desires. 

For example right now it pains me that the F15 FM is suddenly broken, and it will kick the butt of the F16 in many cases where it shouldn't. Or the AV8B basically lacking lift induced drag and being able to outturn every single jet figher in the game atm... 

 

I understand that, really I do... It pains me that the Hornet was out performing the Viper so badly that I was smacking my friend around in BFM when the Viper first came out and all I had to do was get the Hornet slow with my stick in my lap. Now, that doesn't seem to be the case any more but at the time, it was really frustrating seeing him struggle 

Sometimes we need to subdue our passions and just let time take its course 

[Hummingbird]

1 hour ago, lunaticfringe said:

Charts constructed using the same interpolated data set match.

Earth shattering, I know.

No more earth shattering than the fact that such data is very valid in the absence of actual flight test data at SL. 

[Baz000]

21 minutes ago, Hummingbird said:

No more earth shattering than the fact that such data is very valid in the absence of actual flight test data at SL. 

Why do you think such data is "very valid" in the absence of actual flight test data at SL? I think that is the crux of the debate.

[Hummingbird]

1 hour ago, Baz000 said:

Why do you think such data is "very valid" in the absence of actual flight test data at SL? I think that is the crux of the debate.

 

Because it is data deduced by the people best educated & experienced in the field relating to the subject, pure and simple. Hence that is the target you have to go for, not something you calculated yourself.

Thankfully this also appears to be HB's stance as well, because most of the time that's also the case with their F14, e.g. it's very accurate at 5 kft for all I can tell, and at sea level it's bang on the 6.5 G at M 0.62 @ SL as pr. the HM chart. It's just in a few places where it's possibly not matching atm, but seeing as Fat Creason himself said "it's not quite there yet", he's obviously very aware of this. I only have praise for the man regarding the FM.

Finally don't worry, I am very patient, and I have been calling for patience amongst people here too, as I am aware things like this take time - esp. when you got other stuff in your life to take care of. Hence you won't be seeing me criticising HB for the time taken to fix something, esp. when they're letting us know they're working on it, which is all I need to "stay calm" so to speak. 

Edited November 7, 2021 by Hummingbird