Nomad
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Posts posted by Nomad
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Event: 1v1
Squadron Name: Lonewolf
Teamspeak/Discord: you can find me on Splash One or DCS World official discords.
Contact person Discord ID: THD#3335
Aircraft Selection: F/A-18C
Pilots:
Sweden - THD
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I wasn't using the paddle for that, I wasn't even pulling all the way on the stick. If I pulled any further I would start losing speed.
You need to sustain a bit over 8g for that turn which is quite a bit more than the 7.5 the hornet gives you. In fact I just tried this, and at anything faster than 380 it just keeps accelerating.
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Take it for what it is, certainly not the most precise measurements ever, but it should give a good picture of what's happening.
Some insights :
- The Tomcat has both an incredible maximum and sustained turn rate, i have a hard time to control it at low speeds.
- The F-16 seems really close to the available data in this configuration, it would need further testing at different altitudes and loadouts.
- The mirage has the best max turn rate, but the sustain is below its competitors, and it loses energy faster than the others when pulling hard.
- The JF seems to be an incredible knife-fighter, better than the Hornet in both ways, except at really low speed (around 200 knots) !
Again, this would need to be tested with other altitudes and loadouts, but for now, i'm done with it.
Btw, if you aren't already doing so, I would highly recommend to use the mission from here to measure turn rates, especially the sustained rate one, as it has a script which tells you if you are maintaining the flight parameters well enough for the turn to be counted as "sustained".
Are you sure of the hornet data?I can get it to stay at around 22.5 deg/s sustained at 400knots TAS
You need to use the paddle for that, and the testing done by Pamenchan is without, which is correct if you want to compare the performance of the dcs planes to the rl charts/popular opinion.
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I think it's funny that people use YouTube videos when you have no idea what's speed, what wait, what weather conditions... what altitude all of this is happening.. and the load factor..
Sent from my SM-N950U using Tapatalk
You can get a very good idea of most of those things by just paying attention to certain details in the video.
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THD
Lonewolf
Sweden
135ms
F/A-18, F-16
Blue
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Sorry Chuck, but no, I don’t think your diagram is right, nor the first bullet point. It’s a bit late tonight, but I’ll think about it more in the morning!
The first bullet point (aspect angle definition) is in fact correct, just uses slightly different wording, while the diagram is wrong, the blue and green angle arcs should be around the target instead of own aircraft.
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I assume the little numbers below the contacts are their altitudes, yes? This is a big plus over the Hornet because it gives a much better total global picture compared to only having that info on a single contact.
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Can't say that I do. I am still very new to DCS and learning at a break neck pace to try and keep up with most of the conversations here. I'm only chiming in with talk about physics and force diagrams because I like physics, and feel I have something to potentially contribute in that narrow regard.
As I said before, I am not overly worried about the turn rates of any particular plane so much as I am curious about the principles so I can know how to find the edges of the flight envelope vs the edges of my limited skill, and mostly so my practicing is more useful and not wasted on trying to push past actual physical barriers, or to know when I have stumbled upon a new trick or started to master some necessary & important level of fine control. I've been playing for a couple months and just did my first successful aerial refueling mission last night. Just so you know where I'm coming from.
Oh but this was not aimed at you, but more in general, at an arbitrary forum poster who would find themselves unhappy about the performance of some aircraft and wants to let the public and developers know. If one wants to produce useful data, it is always best to stick to the most reliable measurement methods. That said, you contribution is welcome, although I kinda wanted to wait and let Hummingbird work it out on his own. ;)
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Hopefully this post clears things up a bit, and provides an example of why it is always a good idea to verify engineering formulas posted on the internet that aren't backed up by a derivation, and a force diagram.
The real lesson here is that it is always better to measure things as directly as possible if one can. You want to argue about turn rates? Measure the turn rate. Yes, they might be using the g load in rl, but it is most likely because it is much easier to just record data from an accelerometer than to determine an aircraft's exact position and velocity vector 10 times per second. But since DCS is a computer program, and we have full control over what happens and what information we receive, there is no reason to not do things in the most convenient way possible.
TL;DR: use the goddamn rate mission.
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Err... the infobar G reading doesn't work like that, it only shows the G about the centripetal axis, i.e. toward the center of rotation. You can check that yourself by doing for example 90 deg climb or dive. If it didn't work like this it would be useless for our tests. Same deal for the HUD reading.
Incorrect, what it shows is the vertical component of the force that acts on the sensor in aircraft's coordinate system. In simple terms it show how hard the seat is pushing up on the pilot's butt (but not his sides or back). When you are in a vertical climb, he is resting on his back instead while his butt takes zero pressure, hence you get 0G. Be in a climb that is anything else than 90 and you will see numbers on the G-meter. Same applies for bank.
Hey, you can do a simple problem: find out what turn rate your plane is doing in a straight and level flight. First answer that using common sense, and then use the formula and see what you get.
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If you go by Mach alone you would have a point Nomad, but why on earth would you ever do that? You should ofcourse go by the TAS reading, which is in either kts or km/h, and not the HUD mach number. My infobar readings are in km/h (I'm Danish, so I like it that way) before I converted it to kts. So for a SL Mach 0.65 reading I would aim for 796 km/h at SL. So the speed readings are plenty accurate.
Thus your biggest rounding error will be with the G reading, and the infobar seems to only round down, i.e. it will only show for example 6.1 G when 6.1 G is reached, not when at 6.06 or 6.09 G. And it will continue to read 6.1 G until 6.2 G is reached and so on. Hence G readings have up to a negative 0.09 G possible rounding error.
Also like I pointed out earlier I ran these tests over and over again to get an accurate average, I didn't just run it twice or three times. I did at least 10 to 15 of these runs.
Either way like I said I don't mind a 0.2 deg/sec discrepancy, what I do mind is when we hit 0.5 deg/sec or more, and at 15 kft I'm getting over 1 deg/sec more in the F/A-18 than what the GAO report lists as the max STR at that altitude, and at at SL its the same if you use the paddle, and as a result the F/A-18 is outrating everything.
There is another thing as well. For any non-90 degree bank angle your G readout will have a vertical component due to gravity, which will result in a higher readout than you'd get from just the turn acceleration. This will make it seem like the turn rate is higher, so you want to correct for that too.
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There's nothing incorrect about the calculation. Again refer to your textbook.
Sigh... I guess I'll give up on trying to have you figure it out and just explain.
Look, when you have a digital readout of a variable that's normally continuous from, say, DCS infobar it will be rounded, in case of our infobar the Mach number is rounder to the nearest hundreth, and the load factor to the nearest tenth. This means that a reading of M 0.65 for example is in fact anything between 0.6450... and 0.65499.... Same applies for the G number. Now if you plug in the min and max possible values in the formula you can see the interval in which the end result (your turn rate) can vary.
ϵ_1 = 4.6499999 * 9.81 / (0.645 * 340) = 11.9 deg/s
ϵ_2 = 4.55 * 9.81 / (0.6549999 *340) = 11.5 deg/s
As you can see, the final result can vary by about 0.4 deg/s. You can write it as 11.7 ± 0.2 deg/s, or ≈ 12 deg/s, rounding to two significant figures as your Mach and G numbers. And this is just the measurement uncertainty, and doesn't include user error, such as failing to stay in desired flight parameters, and will likely lead to even bigger errors in the end result. This is something you can't ensure properly, which is why you were told to use the turn rate check mission, which not only provides you with assistance to maintain a good turn, but also calculates the turn rate directly from the change of your direction. If you want to have the G load logged, it is easy to modify the script, it's sitting inside the mission file.
That said, there's still going to be some errors since the limits you have to stay in have some leeway (otherwise it would be way to difficult to do it) so ideally you should do a bunch of experiments around the same speed/g load, record the results, calculate averages, confidence intervals etc. Some work, but if one cares as much as you do, then why not? ;)
P.S. There are better ways to do the above math, this is just more instructive. You can read more about that here:
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I think we should wait until we see the changes regarding early onset of GLOC
Indeed, if this ends up being close to what real pilots say about g-tolerance, it's going to be great and probably the biggest "buff" the Viper can get. If on top of that they also let it sustain 9.3g as some people claim it should, it will certainly be quite competitive.
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That's a fair point, and I considered it before posting, understanding that part of your point is about the small reported turn rate delta could fall under "uncertainty" of a low sig fig inputs. Just fyi, I don't necessarily disagree with you. However, given that the 2 angular speeds above are calculated from different figures according to diffently derived formulae using different physical properties, and are off by only 0.01 deg/s
You need to be careful with stuff like this, sometimes it could appear to match but only due to luck with the numbers you are given. Let's say you added a bit of extra thrust in your example and are now pulling 7.5G instead of 7.3, with the rest being the same (TAS = 564 knots = 290 m/s). What bank angle would you have?
ϵ = Gg/v => ϵ = 7.5*9.8/290 = 0.253 rad/s = 14.52 deg/s (old turn rate = 13.75)
bank angle = arctan(14.52 * 564 / 1091) = 82.4 degrees, which on the digital readout that rounds to the nearest integer (like the DCS infobar does) would still show "82".
, it's a bit more likely that there are implied zeroes after each of those 2 digit numbers because DCS has to quantize steps between variable g force and bank angles at some figure. Why not the same values shown both in game and in tacview?No, the numbers are just rounded off. While the steps are indeed "quantized", just like anything digital, those steps are nowhere near 0.1G or 0.01M (you'd feel very noticeable "bumps" if it was like that). Check for example this picture of the modified turn rate mission output, the really long numbers at the bottom are coordinates from which most other things are calculated, and I have the M number show 6 digits:
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Would love to just discuss numbers, but it is difficult to do so without occasionally having to question the competence of people who don't know how to work with experimental data properly and use arguments such as "my 13 ± 0.5 result is clearly larger than 12.9 on the chart, so the flight model must be changed!" I mean, how else is one supposed to explain? Thanks for cleaning the thread up though.
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Prancing Killer, I enjoy physics conversations when people work together to find an answer. Being humble is important. I mean, I have a degree in astrophysics, but I'm new to DCS and the physics of aviation, so even I'm scratching my head at the strange short hand of skipped derivation steps in the formulae above, and I'm quite used to highly abbreviated derivations in proofs.
That being said, the formulae do work, eg:
On the viper you could use the HUD velocity switch toggle for true airspeed, and the G indicator in level flight. So for say a bank angle 82 deg G=7.3 and TAS = 564 knots = 290 m/s :
ϵ = Gg/v => ϵ = 7.3*9.8/290 = 0.247 rad/s = 13.75 deg/s.
You can also use the rate of turn formula ω=1,091tanθ/V and where θ is the bank angle and get the same result.
ω=1091 tan(82) / 564 = 13.76 deg/s
So the fact that you are getting a 4 figure result from an obviously rounded off 2 figure measurement does not bother you at all? You don't deal with experimental uncertainties in astrophysics or what?
What do you mean a copy of a formula from the internet?? It is THE formula for calculating rate! Go look in your textbook please!No, the funny part was how you copied the derivation of the formula symbol for symbol from that website without any particular reason, you could've just said "ϵ = Gg/v".
ϵ is rate, and if you follow the formula then for M = 0.65 & G =4.6 at SL that is 0.203 rad/s or 11.63 deg/sec.This answer is not complete (and incorrect), you should check what I wanted you to do again.
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I didn't realize using actual flight test data was considered "simplified maths". You guys are really digging deep.
The formula for calculating rate:
x = r ⋅ θ ⇒ (dx/dt) = v = r⋅(dθ/dt) = ϵ
G = (Fcpt/Fg) = (mv^2/rmg)= vϵ/g
ϵ = Gg/v.
Congrats, you managed to copy a formula from a page on the Internet. Now tell me, given the precision of the measurement results (G and M you get from the infobar) the game can provide, what would be the uncertainty in the result and how would you report the result correctly. E.g. given M=0.65, G=4.6 from the infobar, what is ϵ?
And the above is assuming you can actually manage to hold the flight parameters static enough without assistance, which I doubt because it isn't that easy. Using the rate check mission gives you that assistance.
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And yet the F-16 actually has the smallest sustainable turn radius...:music_whistling:
At slow speed where it turns like a brick. While the 14 can match the 16's best rate while needing less speed and thus having a smaller radius, which does matter and you know it.
Also funny how the real life pilots don't find the Hornets pitch rate to be the end all in a dogfight...Could that be because they don't routinely over-g it like people do in dcs? There's quite a bit difference between going 450-500kts and having an ability to pull 10g to trade speed for angle and still come out of that with a nice 350kts versus having to start at those 350kts because otherwise you will just overshoot if the opponent does anything. And btw there's plenty of articles written by pilots where they say that Hornet's nose authority is a very strong point, you just choose to pretend they don't exist.
Aha, so now I'm "demanding" changes, pitchfork, torch and everything eh?Sorry but you clearly don't know my posting history, but to brief you: My main focus upon the release of a module in DCS is to flight test and compare it with available documentation in order to make sure the FM is as accurate as possible, which usually never happens on the first try, and I don't expect it to either as this isn't a simple thing to achieve and I admire the guys who have to code this stuff. I then provide feedback until the FM at least matches the available documentation, leaving any quirky flight characteristics (e.g. F-14 high AoA rudder effectiveness, dutch roll etc) to be addressed by the only ones who truly knows about it, the SMEs aka the RL pilots or engineers who work/worked on the a/c.
Hence you'll see posts by yours truly relating to flight performance in the subforum of basically every jet fighter module in DCS, I didn't just start doing this yesterday. The F-16 just so happens to be the newest module and still needs some adjustments, so currently I'm more focused on its FM.
I don't have any feelings attached to any one particular aircraft, my wish & main focus is that they all fly as realistically as possible, pure and simple.
So why don't you stick to discussing the F-16 alone? There's enough documentation available for it, unlike the 18, to analyze, so that you don't need to base your arguments on "some pilots say that 16 is better than 18 in dogfights, but it isn't in game, pls nerf thx". To even do this you should at least try to understand the reasons the DCS Hornet is stronger in BFM compared to the real one, and protip: it isn't because it "might" (don't even have detailed documentation, so essentially unconfirmed) be turning some 0.2 deg/s faster in a sustained turn.
It does seem like the F-16 is underperforming in certain aspects, but to show this you don't need to compare it to another aircraft, in fact even ED themselves explicitly stated that they don't take such comparisons seriously. Use the available data for the F-16.
15,000 ft
M 0.65 = 4.6 G's (12.5 deg/sec)
M 0.75 = 5.5 G's (13.0 deg/sec)
M 0.80 = 6.0 G's (13.3 deg/sec)
This is wrong in more ways than one: firstly the methods you use are prone to producing errors because there is nothing that forces you to stay within set flight parameters, you should use the sustained turn rate check mission instead.
And second, you convert two different two-figure measurement outputs into a three-figure result which is an incredibly amateurish mistake, because you should know that since school, if you paid attention. This alone makes me doubt about you having any background in the subject beyond the aero for dummies course you linked.
Aha, so now you're arguing against the actual documentation there is available? Well we certainly know what box to put you in then.
Show me some real documentation about the 18, similar to what we have on the 14 and 16, not just some random report which contains 2 data points. Send through PM to not violate forum rules.
You misunderstand, said course was for you :thumbup:
I'd recommend reading up on lift coefficients first, as you seem to believe these aircraft rely on secret woodoo magic to stay airborne. If we're lucky you will then soon understand why calculating the STR or ITR is very easy when the engineers & test pilots already did all the hard stuff for you, aka an EM chart.
I prefer to read proper textbooks when looking into something even for hobby purposes, in this case I have this one. So don't need your link, but thanks for your concern. You though, should read up on significance arithmetic and error propagation, or better yet stop skipping science classes to play DCS if you're still in school.
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yeah and i'm sure you'll fly this way in real life if for example there's the possibility that you dont hit me and then have to give up angles after that because you fall down like a rock, trading your life for a snapshot that if you miss you can't fight anymore. as i said, wrong flight models lead into this kind of bad habits.
How about not going for it unless you know you'll hit, then you won't have to deal with all that falling down like a rock stuff and further unpleasantries? Also, there's more nuance to it than pulling on the stick until you're at 50 knots, you know. And do I need to mention the slight differences between DCS the video game and real life and how that affects the decision making?
Also, how is DCS Hornet's FM bad now? Because you think it's off by 1% from some chart? (let's assume it's real). Yeah, horrible FM, ED should totally rework the whole thing from scratch.
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2 deg/sec might seem like a small difference to you, but it becomes quite noticable in a dogfight between pilots of equal skill. The F-14 currently holds about a 2 deg/sec advantage over the Hornet, and that quickly becomes deciding in a turn fight.
F-14 also has a very good ITR and small turn radius, while F-16 has neither. These are the reasons it does so well, not just STR alone.
I don't know where you got the idea that anyone wanted to boycott ED over a slight performance discrepancy, or that I care about which aircraft wins a dogfight. All I care about is that RL performance is matched as closely as possible, and I'm quite patient about it too, not once having threatened to do anything. So you can pack your childish attempts at ridicule away thank you very much.You do care though, otherwise you wouldn't be constantly comparing the two, posting in every 18 vs 16 thread and demanding changes on the basis of "this plane should beat that plane because I read that somewhere on the Internets".
Also your results hide the real problem, which is suspicious performance above 0.7 mach, which becomes clearer and clearer the higher you go. At 15 kft the DCS Hornet is already pulling 1.1 deg/sec more than the figures in the GAO report, and that without using the paddle.It does turn slightly faster, but not by 1.1 deg/s.
2019-11-20 20:53:38.567 INFO SCRIPTING: TR: Counter, Alt(m), GS(km/h), GS(Mach), Turn Rate(deg/s)
2019-11-20 20:55:06.236 INFO SCRIPTING: TR: 0 4489 876 0.756 12.7
2019-11-20 20:55:43.139 INFO SCRIPTING: TR: 1 4519 927 0.801 12.8
2019-11-20 20:56:57.777 INFO SCRIPTING: TR: 2 4561 1206 1.043 10.1
2019-11-20 20:58:55.718 INFO SCRIPTING: TR: 3 4598 939 0.812 12.6
2019-11-20 20:59:53.584 INFO SCRIPTING: TR: 4 4571 968 0.836 12.7
2019-11-20 21:02:37.962 INFO SCRIPTING: TR: 5 4572 849 0.734 12.3
2019-11-20 21:02:57.849 INFO SCRIPTING: TR: 6 4587 813 0.703 12.0
This could be specific to the Hornet, or something general like how DCS models the atmosphere. Too lazy to check if the Viper's performance matches right now. Could also be that the "12.3" figure is fantasy because there is no proper document about F-18 performance, just random stuff from the internet that people assume to be true.
You really ought to read up on aero before you start poking fun at someone who actually understands it.Start here:
You impress me more and more, not only do you have the ability to highly accurately predict the performance of any aircraft by doing a quick calculation on a napkin, but you also only needed to go through an "aerodynamics for dummies" course to do that! Do you happen to have 180 IQ?
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that's just wrong, maybe in wrong flight models where you dont lose the speed that you should that might feel worth to pull max g's for snap opportunities, start to have a plane that slows down as it should and take the time that it would need to take to take back the speed and you'll start thinking in a different way.
Bad flight models, bad habits.
Let's put it this way, if I pull hard, shoot and hit you, who cares how slow I am after that?
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Yes, 19.4 deg/sec, that's 0.2 deg/sec more than the GAO report.
In short you just confirmed what I've already said, the Hornet is slightly overperforming atm, which when put together with the fact that the F-16 is slightly underperforming both in STR, level acceleration & G-onset, makes for a very noticable advantage in the Hornets favor that the real life aircraft just does not possess.
Wowzers, an entire 0.2 deg/s! Which is a whole 1% of difference!!!11one. This is obviously a conspiracy because such things as measurement errors, differences between individual aircraft (in rl), and slight and acceptable modelling deviations in DCS could never possibly combine to create a difference as enormous as 1%. We should boycott all ED products until the Hornet's turn rate is adjusted to 19.2 because this will change everything and it will get absolutely dumpstered by the Viper in a dogfight and order will be restored.
No it's not, you can calculate it quite easily. So you can stop being smug, thanks.I think you should have a chat with Boeing, Lockheed Martin and all those guys, because I believe they are still wasting their time testing this stuff with real airplanes and wind tunnels and such, which is obviously retarded because it takes you five minutes to easily calculate it on a piece of paper.
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why should the paddle switch help you having a better sustained turn rate? pulling more g's will result in losing speed, if above the sustained level, sadly we dont know how many g's the GAO hornet is pulling to sustain that turn rate, or how fast is he going while sustaining it, you would need a chart that we dont have, so the information is quite not usable.. we dont even know if, for example, he's using the paddle switch considering that it's a performance test
Well first, the DCS Hornet reaches its best STR above the 7.5 g limit, and second - this is not even what I was talking about, I meant that it will not lose any dogfights to the Viper any time soon because the ability to yank the stick and point your plane where and when you want it is actually quite a bit more important than a slight edge in STR, so even if the Viper will have that edge at some point, it won't help very much.
In fact the biggest buff to its dogfighting ability will be the g-tolerance revamp, mentioned by Wags, because then you might actually be able to fly like a Viper is designed to without blacking out.
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No idea, but words from an Hornet pilot has to be considered in this case aswell?
And another one said it felt heavy and draggy, so who's right?
I never heard from a pilot that the Hornet can sustain better max turn rate then the viper, i did heard only the opposite. So if any pilot could came and say that, i think everyone will be satisfied and discussion's overNever heard that either, but then again, dcs hornet doesn't really outrate the viper as long as you stay within the 7.5g limits, they go about even. Now if viper is 'buffed' as it seems to be very slightly underperforming according to some people, it will have better STR than hornet. Still won't make it win any dogfights because paddle switch exists, but at least maybe the threads will stop? Probably wishful thinking though.
F-14b sustained rate of turn.
in Bugs and Problems
Posted
Except that it doesn't, so why don't you look again?