Su27 Wing Thing

[lunaticfringe]

- Direct from manufacturer? You want to say that you contacted Sukhoi Design Bureau and they gave YOU structural data? Or you(ED) just read the Su-27 manual?

 

Translation: "The chart I misinterpreted and had to be corrected upon from the Su-27SK manual, page 9, is gospel, and I demand ED make the aircraft match it, even though I don't actually understand the underlying physical relationships at play, because Sukhoi provided that data to the PVO to publish.

 

Meanwhile, the structural limitations chart from the same manual, page 15, is garbage, because it makes me look like a hamfist who doesn't know what he's talking about."

 

 

- G safe operational...yaddayaddalookatmydegreeyaddayaddaIneedtoshoreupmycredibilityyaddayaddaforgetthefactthatIclaimedtodesignairplanesbutdon'tknowhowgravityaffectsaloadedwingyaddayaddabuildawallofwordstomakemyselffeelgoodyaddayaddayaddaPS: My stick has wide (5cm) play without extension. Its worn out. That could cause that excess in MP. Not sure.

 

Translation: "I don't understand the most basic relationships of Mach, weight, the force of gravity, and the application of load on a wing, but I'm going to continue saying ED doesn't know what they're doing.

 

In fact, I'm going to blame everything under the sun that I possibly can- up to and including an inanimate object, to obfuscate the fact that I'm not enough of an adult to admit that I am the one who screwed up and pulled too hard on the stick."

[jackmckay]

Tharos, you look reasonable enough. Someone should test that in virtual wind tunnel and verify model performance and loads (I could but I'm not payed for that job). I would if I was responsible for ED's damage model algorithms. Just to kick suspicious minds like mine out of arguments.

 

Lunatic, you're funny and that bla bla thing is kind of immature, but really funny. :) And that gravity thing.. well I'm actually skydiver so I felt it disappear in free fall many times and that one G really counts.. that youtube guy explained it for you on one of my recent post..

 

At first I didn't wanted to give you The "PS Thing" but I did just for fun otherwise you couldn't grasp straws and I would look to much pissed off but it passed me as I was writing replies.

 

Anyway, damage model is f* up for Su-27. Period. Why ED didn't introduced that glass wing feature from beginning..? I don't know, but I can speculate. So I speculated, and speculated and speculated again and came to conclusion that there could be some kind of thoughts going thru the heads of ED masterminds.

 

Thoughts like:

 

We(DCS) will always (everything is subject ti change thing) broke and fix things in DCS so that we could always have necessity of our contracts and safe jobs for eternity.

 

We (ED) will fine tune (read broke) previous releases and manipulate clients to buy new modules that are not so broken now (but they will be as soon as next new module is released). If there is necessity We(ED) will "balance" powers by making some planes superior to other by crippling advantages of real life superior planes just to have more money from ignorant players who don't give a damn about physics.

 

We (ED) don't give a shit because we are THE ONLY "Serious" combat flight sim developers on the planet and our community is so used to this shitty fun&learning curve killer errors that they become stress tolerant and ignorant to bad products.

 

We (ED) have more serious job by developing some real-thing error-free commercial sims that we sell to military clients worldwide.

 

I will actually start Kickstarter project to save the souls and nerves of virtual pilots soon. If ED finds out of this intention they could finally make some real-deal changes. I keep in mind that I payed 600 bucks for broken "game", some 600 more for gaming hardware and some 7500 bucks for new hardcore PC to have bad FPS and constant game/fun killer experience. I have to be an idiot, but I still play MP because of people I respect and love in virtual sky.

 

Respect to MP community. :thumbup: We're flyin' true hard days now but sun will shine thru the clouds my virtual friends.

 

[DarkFire]

Thoughts like:

 

We(DCS) will always (everything is subject ti change thing) broke and fix things in DCS so that we could always have necessity of our contracts and safe jobs for eternity.

 

We (ED) will fine tune (read broke) previous releases and manipulate clients to buy new modules that are not so broken now (but they will be as soon as next new module is released). If there is necessity We(ED) will "balance" powers by making some planes superior to other by crippling advantages of real life superior planes just to have more money from ignorant players who don't give a damn about physics.

 

We (ED) don't give a shit because we are THE ONLY "Serious" combat flight sim developers on the planet and our community is so used to this shitty fun&learning curve killer errors that they become stress tolerant and ignorant to bad products.

 

We (ED) have more serious job by developing some real-thing error-free commercial sims that we sell to military clients worldwide.

 

This has been an interesting and informative thread up to now, but with respect this ^ is starting to sound like some sort of conspiracy theory. I'm done with this thread.

[probad]

other than the 3 people valiantly waging a futile struggle against ignorance and denial, im pretty sure everyone else has been done with this thread for 15 pages or so now.

[jackmckay]

This has been an interesting and informative thread up to now, but with respect this ^ is starting to sound like some sort of conspiracy theory. I'm done with this thread.

 

I completely agree. Its a speculation based on MY feeling accumulated over some time spent in DCS community. I have legit right on that.

 

@probad this tread is seen by 7k people now. People still read it.

[mvsgas]

[ATTACH]150393[/ATTACH]

 

 

 

[karambiatos]

These last posts by certain individuals, is a good example as to why the English speaking side of the forums is absolutely abysmal.

[Ironhand]

Sooo...

 

 

I've been playing around with this off and on for a few days in a very unsystematic way and, so far, I have been able to hit the AoA figures (momentarily) for M 0.5, 0.6, & 0.7. This is with the limiter engaged and, actually, with 4 R-73s on the wings. (I keep falling short of the AoA figures for the higher M numbers. Just haven't been able to force the AoA to reach that high.) And, so far, the wings have stayed on in each trial.

Edited October 21, 2016 by Ironhand

[Pocket Sized]

I think I'm misinterpreting your post, but "max permissible" = maximum allowed.

 

It doesn't care how you reach said AoA's it's just saying not to exceed them.

[jackmckay]

Quote from Sukhoi Company regarding high performance airplane (not-Su27 though):

 

..In static tests the airframe reached a breaking point under a load of 22.5g. The aeroplane's aerodynamic performance does not make it possible to achieve more than 18g in flight. The operational 12g limit imposed is due to human physiological capabilities.

 

End of Quote.

[Ironhand]

I think I'm misinterpreting your post, but "max permissible" = maximum allowed.

 

It doesn't care how you reach said AoA's it's just saying not to exceed them.

You're not misinterpreting. Those are supposed to be the max allowed for those Mach numbers. In the sim, I usually fall 2-4 Gs below the max allowed despite my efforts to exceed them. But, on a few occasions, I have exceeded them without the wings coming off.

 

The only reason I'm paying any attention to this is jackmckay's post: here . I was intrigued by the numbers.

[Pocket Sized]

You're not misinterpreting. Those are supposed to be the max allowed for those Mach numbers. In the sim, I usually fall 2-4 Gs below the max allowed despite my efforts to exceed them. But, on a few occasions, I have exceeded them without the wings coming off.

 

The only reason I'm paying any attention to this is jackmckay's post: here . I was intrigued by the numbers.

 

Try it with low fuel (20ish percent) and R-73s on the wingtips. The aircraft will be very tail heavy and more sensitive in pitch.

[Ironhand]

Try it with low fuel (20ish percent) and R-73s on the wingtips. The aircraft will be very tail heavy and more sensitive in pitch.

:) That just so happens to be how I reached the first 3 Mach number AoAs (gross weight: 21,400 Kg).

[probad]

he's trying to say if a 300lb civilian aircraft can take 22gs, then surely a 60000lb military aircraft should also take 22gs

 

:doh::helpsmilie:

[probad]

i honestly have no idea how i ended up putting down 300lb but yeah

[jackmckay]

Su-26 FOS 1,875 (12G) ..if design G limit was 9 then FOS would be 2,5. Russians have higher factor of safety as seen on this example. I'll look for more and paste here.

Edited October 28, 2016 by jackmckay

[SinusoidDelta]

Su-26 FOS 1,875 (12G) ..if design G limit was 9 then FOS would be 2,5. Russians have higher factor of safety as seen on this example. I'll look for more and paste here.

 

I hate to stir the pot here, however, that is in no way relevant to the Su-27. If you find information that pertains specifically to the Su-27 or one of its variants feel free to post it.

[jackmckay]

I hate to stir the pot here, however, that is in no way relevant to the Su-27. If you find information that pertains specifically to the Su-27 or one of its variants feel free to post it.

 

Its actually same factory. But you're right, best example would be if we could have wing breaking point data from real wing test committed at TsAGI institute. I asked them but yet no reply.

[Veritech]

As I was talking to Birdstrike online a couple of weeks ago, although I think that breaking wings happens "easily", we don't have to forget that a Flanker fully loaded with fuel and weapons is heavy as hell. Have in mind that some of the fuel is stored in the wings, as well as 6AAMs...

I had the "wing issue" before and I have to admit that sometimes it happened because of my own mistake of pulling too hard too fast, but in a small percentage of the situations they indeed broke off in situations where I think it shouldn't have: less than 5.5k L of fuel and with 4 Archers hanging from the wings.

 

I must add as well that lag/sutter sometimes over exagerate the joystick's input giving way to undesirable outcomes :P

 

Just let's stay put, relax, sit down and wait until these issues (as well as several other developing points) are addressed by ED. Let's remember that they are awfully busy with the preparations of the 2.5! (To which I must confess, I feel as eager like a small boy in Christmas Eve).

[ShuRugal]

Have in mind that some of the fuel is stored in the wings, as well as 6AAMs...

 

This is actually the best place for weight on an airplane to be.

 

Wings break off of overloaded airplanes not because the wings are too heavy, but because the fuselage is: The limiting factor is the strength of the wing root. Since the wings are cantilevered on almost all modern planes, all the force of lift that the wing generates must be communicated through the wing root to the body of the plane, and vice-versa all the weight of the plane must be supported by the wing root.

 

Fuel evenly distributed throughout the plane places almost no strain on the wing, because the weight of the fuel is directly in-line with the lift supporting it. Likewise, the only strain external wing stores place on the wings comes in through the hardpoints. The weight of missiles on hardpoints and fuel in the wings will never separate the wings from the body, because their weight is not communicated between the wings and the body.

 

This is why flying-wing designs never go fully out of the vogue: If the entire airframe is your lifting surface, you can spread the weight and the lift around evenly and avoid concentrating stress in one particular area.

[DarkFire]

I wonder if the wing destruction G loads might need looking at again. I was flying around on the VA server tonight and decided to deliberately break the wings. Having previously over-stressed the wings by a 9-G split-S (6000Kg fuel and equivalent of 3 x R-73, resulting in weight being well over 21,400Kg) I then took it to M1.2 at about 100m altitude (~1400Km/h) before sharply pulling up. The wings broke but not before the G meter went well above the 9G marking.

 

I wonder if the wing strength has changed without it being advertised in the patch notes? Unfortunately TacView decided to experience a SNAFU and decided that when my wings broke the aircraft had in fact disintegrated whereas in reality I had enough control to be able to level off and eject safely.

 

Going to have another look at this tomorrow to see if this is repeatable.

[Veritech]

I wonder if the wing destruction G loads might need looking at again. I was flying around on the VA server tonight and decided to deliberately break the wings. Having previously over-stressed the wings by a 9-G split-S (6000Kg fuel and equivalent of 3 x R-73, resulting in weight being well over 21,400Kg) I then took it to M1.2 at about 100m altitude (~1400Km/h) before sharply pulling up. The wings broke but not before the G meter went well above the 9G marking.

 

I wonder if the wing strength has changed without it being advertised in the patch notes? Unfortunately TacView decided to experience a SNAFU and decided that when my wings broke the aircraft had in fact disintegrated whereas in reality I had enough control to be able to level off and eject safely.

 

Going to have another look at this tomorrow to see if this is repeatable.

 

+1

 

Thanks for. That info

[DarkFire]

Well, this is interesting.

 

I just did some tests whilst flying on the VA server. Standard DCS day, albeit with dynamic weather. I loaded 9 x smoke pods, full gunpad, full expendables and full fuel for an all up weight of 27,827Kg. Well above the Beti calibrated value of 21,400 Kg.

 

I took off an accelerated to maximum speed at around 1,000m altitude. This was about 1,300 Km/h TAS or about M1.15. Well within the 'danger zone'. By the time I'd accelerated I was down to ~8,000Kg of fuel, so an all-up weight in the region of 26,400 Kg. Again, well within the danger zone.

 

I carried out 4 different sustained turns, on each occasion gradually increasing the G load until I approached G-lock and then eased off.

 

For each turn the G meter read a maximum G of between 8.5 and 9.5. At no point did I suffer airframe damage.

 

Might be time to do a proper re-evaluation of the point at which airframe destruction happens.

 

As an aside, I had the control position monitor turned on and as G went above ~8, the AOA limiter chased around the control column position. The effect of this was to create a sort of pitch oscillation which, at maximum amplitude, added about an extra G to the airframe load value. It may well be the case that the AOA limiter is actually to blame for causing airframe damage when carrying out high-G manoeuvres right at the edge of the airframe capability.

[*Rage*]

Good stuff Darkfire. I wonder if we could get a comment from ED if something has changed.

[DarkFire]

Good stuff Darkfire. I wonder if we could get a comment from ED if something has changed.

 

Thanks. If something has changed it'd be useful to get a comment from ED. My tests were quite rough & ready, and of course MP can do weird things some times, but I think it's worthy of further investigation. I'll do some more SP environment tests tomorrow when I get in from work.