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.

- 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? - G safe operational limit not ultimate structural limit. In fact I posted several tracks in which I exceeded stick pull up to 100% at very same conditions and survived the very same maneuver in which my wings broke off in MP. Repeatedly. - Yes, ED fails to calculate wing snap-off G limit point, point of wing separation. Until ED shows CFD/FEM analysis data there's no at least some guarantee that damage model is accurate at all. Actually its completely ****ed up. Period. - Su-27 aircraft is designed as all weather high maneuverability fighter with just predicted right load-out for exact purpose and just right predicted flight envelopes. The safe margin excess is given by factor of safety that you or the ED does not know. They can just speculate but I can tell you that Russian air-frames are designed for low maintenance front line operations traditionally and that means higher safety factor than US airplanes. - Wing load is direct proportional to frontal projection of wing itself, that gives correlation between speed, AoA and vertical force vector on wetted, stream exposed wing area. High speeds implicit high loads on high AoA and high (ultimate) loads are matter of discussion here NOT stall behavior. - Yes, just for example case but again Russian military safety standards are higher than Western. Guaranteed. Russian FOS is always higher than US FOS as a matter of fact it goes up 2,5 (2vs5max at static loads!) as I was tough at mechanical engineering college from certified professors from former Yugoslavia that had both insight from USSR and US technology. Prof for that is maintenance time needed for Russian versus US airplanes. - That stress-strain chart is for example and it shows steel elastic properties as focus was on ELASTIC properties. In fact, you have to know that airplanes are not made entirely of aluminum. Some very important high load cycles parts are made of either steel or titanium or any other suitable material properly strengthened for right design given function. Air-frames are composite structures. - I stand before my claims because I am mechanical engineer Sir. That is my profession. You on the other hand are, as I figure out from your words, programmer, and you read lot of manuals. How many manuals for new design airplanes have you written, or how many mechanical components have you designed, tested and verified? And if you don't believe me, what is your legit right, why don't you first ask some mechanical engineer about airplane structure design basics. So this is my conclusion on this topic regarding Su-27 airframe design aspects in DCS. - DCS Su-27 IS NOT CERTIFIED by TsAGI institute who designed winbox of Su27S; - DCS HAS NO VALIDATED independent structural tests committed on ANY flight (damage) model using certified and industry approved FEM/CFD software at least (for ex. ANSYS/FEMAP/COMSOL). - Flight Manuals are written BY designers (aeronautical/mechanical engineers) FOR users (pilots) to maintain high availability and to fulfill airframe predicted lifetime - that means flight performance margins are NOT kill switches. Life of pilot is too precious. Period. Tight relation to real world damage model with ED's damage model shows this picture. Here we can see perfectly functional F-15 returning RTB from SATAC mission after killing one of my teammate. Praise the western engineers. PS: My stick has wide (5cm) play without extension. Its worn out. That could cause that excess in MP. Not sure. Birdstirke OUT.

Take a look at these tracks. Tracks.zip

You got to kidding me. Your speed was (litlle bit) over 950 kmh IAS every time but I can live with that. Second, my planned maneuver was high speed descend at -30(-35)deg elevation (roll -180, pull -30deg, reduce trust, roll leveled, pull 30deg) without much energy build (I was entering combat engagement zone plunging at the deck) NOT SPLIT-S maneuver at 1350 kmh IAS on gravity vector G build at lower point of recovery. That's very much inconsistent, sorry.

@GGTharos Then why overloaded su-27 didn't get chance to be written off at ground instead of instantly destroyed airborne? 30-40Gs was applied on airframe for a fraction of second (as mentioned in vid) and even to me it is still suspicious. USAF had flight recorders to check G spikes after all. So how we can test it away from ED's (at my point of view) suspicious DCS su-27 coding? Should I make 3d detailed model and make some FEM/CFD structural test to see who's right or wrong in this case?

U-2 has fuselage of F104 and very long wings with high L/D ratio because it is designed for HA Recon. It's not high maneuverability fighter plane and not same class. Su27 is G9+ fighter capable of very high G loads too as F15/F16, structural limit is G9*1,5FOS=13,5G BEFORE plastic deformation. Other factors like hardpoint weights inertia, wing fuel sloshing, elevator deflection increase loads on wingbox in respect to AoA and indicated airspeed and flying down the gravity vector decrease it. Its not that simple formula as you think and no G limit is reduced only load factors increased. You used formula for variation of the load factor with the bank angle during a coordinated turn, but case here is vertical turn down the gravity vector with turn radius indicated by AoA value as tangential deflection vector. Guy in Eagle pulls so much Gs(30-40) but his plane remained in one piece: You're telling me that Su27 wings are made of Swiss cheese and that they disintegrate at less than 10G. That's bullshit. Period.

@lunaticfringe FAR 25 Aircraft components Ultimate FOS is between 1.5 - 2.5 depending on load margin and position. Killing airplane with FCS off is not possible or easy at least because no designer will ever allow that. By the way, operational margin avoids plastic deformation on structural components. @Ironhand stalling wing at high mach is possible but its more likely that airflow drag force vector vertical component will induce high loads on structural components of wing first, relative to AoA.

@lunaticfringe you entered every maneuver with aprox. 10% higher speed. My IAS was around 950, yours is above 1050. Energy vs speed has exponential growth. You pulled your stick 90% to max, I pulled 50% to 60% released.

I opened this topic referring to ED. Who's ED stuff here? Stronger argument goes to people actually flying Su-27 in DCS, so you that fly only F15 quit spitting fire, its a matter of physics and coding not balls or politics. I'm actually mechanical engineer, CDF analyst, structural engineer, graphical designer and programmer. I belong to the group of people that design stuff and write manuals not just read them. My area of interest is fluid-structure interaction, marine application specific and I'm good at that. I design floating objects, internal combustion engines and aircraft, and all kind of stuff. And I actually speak 4 languages so I probably speak yours too. Do you speak mine? Conclusion: No one yet can repeat failure in same conditions so its an anomaly in DCS engine. Period. Its a BUG.

Well, Su27 is high G supersonic fighter, top of the shelf, designed for 8+G constant load, combine it with safety factor of 1.5 and you get 12G structural failure red zone. Its wings are not made of Swiss cheese.

DCS miscalculated G's. Then, redo it (brake the wings) with same conditions (3 times) and paste tracks here. I'll withdraw my statements about everything I said and praise the DCS for the rest of my life.

You should read my posts from beginning. I'm answering this specially for you: 3.9G

That's true but acmi files are low resolution variant of telemetry. In my .acmi file my G's were around 3 and in actual .trk file it was around 9 at which wing failure occurred. Mother of all my question to ED/DCS regarding this topis is: If I was close to structural strength of my wings, at high G value, why my pilot didn't experience any signs of blackout tunneling? Suhkoi wings could have been made stronger if there would be no pilot flying it inside who is very accurate Over-G instrument by the way.

On my latest pre your post first 'G' is actually 1G or g or gravity acceleration value, second 'G limit' is force because it is combined with mass, second Newton's law (F=m*a). Force on area is pressure, pressure challenges structural elements elastic region of Yang's modulus charts and when pressure further increases first occurs plastic deformation or f.ex. twisted/bent airplane and if pressure continues to increase after exiting plastic region structural break occurs. On my previous post I explained the importance of AoA charts and mandatory limitations for airplane safe operation. On high supersonic speeds AoA safe range decreases that's why Su-27 have this limit for Mach 2 on 8 deg and at Mach 1 limit on 18 deg positive G turn. I was around 10 deg AoA when structural failure occurred at Mach 1.25 .

In speed range from minimum to maximum, AoA is proportional value to the speed. This value is so important for the airplane that it has its own measurement device attached to the pitot tube(or somewhere in clean and uninterrupted air stream), actually it's second most important value after speed value. On low speeds AoA limitation tells pilot when his wings should experience stall or boundary layer separation but contrary on high speeds AoA tells pilot the structural limit of his planes wings or when his wings will overload and disintegrate if made lightweight on trade with structural strength. Every airfoil or wing profile is tested in wing tunnel to find its behavior on speed and AoA ranges and is selected to the new design by optimal performance. The best designs heave high AoA capabilities and so that's the case with Su-27 but its more aerodynamic question other than structural which is question of most importance on supersonic designs which is Su27 fighter plane. It's supersonic fighter not Piper Cub. That's why aerodynamic engineers are fascinated by AoA value. And pilots ar fascinated by this number because oh high speed this number tells you when to expect structural failure.

Flight data in moment of wing break: aprox. velocity. 950km/h mach: 1.25 altitude: 7000m AoA: 10deg fuel. 65% config: class 2 (4xR73 + 6xR27XX) weight: 26500kg .. max allowed AoA at this config should be between 18deg at mach 1 and 8 deg at mach 2.. roughly decreased by Group 2 config in 20% decrease of limit and fraction of G help due to inverted position going below horizon. So limit AoA should be for group 1 around 15,5deg for group 2 around 12,4deg worst case scenario. Even all of this should be monitored by pilot there is a 'Nadia' telling you 'ease out on the stick' and i'll make it harder for you so i will put some 15kg force on your stick so you can't excess G limit. Why this limit is not implemented on su27? and why cant we export flight telemetry from .trk files in DCS?

Question: how much of certain amount of G that airframe feels in inverted dive might vary with respect to max AoA? --- And the manual says this::: --- 4.10. Flight to aerobatics. General information The aircraft is allowed to perform a simple shape, complex and aerobatics in a wide range of speeds and altitudes within the permissible angles of attack and overload the ADF (ODA triggered) with the specifications set forth in this subsection. This section examines the pilots on the aircraft with pendants, which are conditionally divided into groups: Group 1 - a plane without suspension or 2hR-73E + 2hR-27R1 (P-27T1), or 2hR-73E + 2 AB caliber up to 500 kg, or 2hR-73E + 2xc-25, or 2hR-73E + 2hB -8M (2hB-13L); Group 2 - plane with 4hR-73E + 6hR-27R1 (P-27T1) or 2hR-73E + 6 AB caliber up to 500 kg, or 2hR-73E + 4hB-8M (4hB-13L) or 2hR-73E + 4hS- 25; Group 3 - aircraft with 2hR-73E + 8 AB caliber up to 500 kg or 2hR-73E + 16 AB caliber up to 250 kg. A WARNING. With other options NOT suspensions perform aerobatics. Features aerobatics on operational and combat training modes engines UR are virtually identical, except for the hill climb. Pilotage performed only when the limiter angles α and Pu. Entering the limit angles of attack IPT overload accompanied by "focusing" (step increase efforts to handle 15 kg) and the stick shaker. This signal is displayed "alpha, Pu CRITICAL", followed by the speech information "maximum angle of attack, limiting overload". ODA system with its correct operation provides high maneuverability of the aircraft at a safe piloting on the boundary limit angles of attack and overload. A WARNING. Overriding "stop" when the maneuverability makes aerobatics significant growth, but can result in the aircraft stalling or excess Pu ext. When creating the set overload rate of less than 2 seconds ODA triggered at small angles of attack and overload. The rate of release at the allowable angle of attack and overload determined by the "stop" while maintaining the pull force on the control stick. For flights at altitudes below 5000 m and greater indicated a speed corresponding to M = 0,95-1,2 may occur rests on a roll and the pedals control knob due to insufficient power hydraulic drives flaperons and rudders, but in this case handling It is sufficient and is 25-30 ° per second. Before performing aerobatics need to tighten (stall) shoulder straps. Check on the RD-15 position of the handle-OFF PRESSURE, which should be in the position PRESSURE. --- I found this table: ... 5. Acceptable angles of attack: A) For airplanes with no suspensions or SD M ALM 0.5 24° 0.6 23° 0.7 22° 0.8 20° 0.9 19° 1.0 18° 2.0 8° B) For airplanes with bomber means of destruction and the LDCs: M ALM 0.6 20° 0.7 18° 0.85 15° A WARNING. During takeoff - landing configuration (landing gear) αdop = 20 °. When you tap on the landing αdop = 16 °. ...

Ok, my mistake then. Even that telemetry looks similar to my Flanker maneuver in one part because roll rate increases, moderate pitch is given and AoA spikes up. .. but.. If both planes are part of FC3 package then why one can export telemetry and other can't? That's weird.

Since English isn't my native language there could be an communication problem but that is what I was trying to explain by using quote 'I was inverted'. I'm glad we agree. Next, based on that conclusion, keeping max allowed G for specific configuration, going inverted below horizon and with gravity assisted turn rate being increased, max allowed AoA limit would be higher than going above horizon (not inverted ofc) keeping same allowed max G, right?

So conclusion would be that: if your plane is fixed on max G limit on specific configuration then -if going up the gravity you would have lover possible turn rate than going down the gravity as you would have higher possible turn rate because it is assisted by gravity, right?

AoA spike(purple) can't be that high compared to pitch(green). Plane wasn't on that turn rate ever(!) during flight. There's been an ERROR in flight dynamics calculation process!

@Sinusoid Thank you for cutting out the actual scene from external view. Now: 1) Look at the elevator deflection angle progress(!) 2) consider that plane is in turn radius with center-point down towards earth .. so G-force would be G=1-(velocity^2/circle radius*g).. velocity is TAS and circle radius could be found roughly with elevator deflection angle (versus center of mass) - which (elevator angle) changes a little(25-50% or 1/4 of stick aft pull) but Gs are constantly rising(!).

All objects with mass inside of gravity force are under the influence of the gravity force vector..

[Nz] ... Weight in formula is product of acceleration (m*a) so there wouldn't be the same G readout if I pulled UP flying leveled or DOWN flying inverted (just because feed pumps will stop working and pilot can withstand more positive Gs than negative) relative to gravity vector(Z) prior entering maneuver and proceeding at constant corner velocity/AoA/turn rate, so this 1G (or g as acceleration) actually decreases weight. ..Lift is product of wingfoil shape (L/D design ratio), wing area, flow velocity(IAS) and air density/viscosity or in short Reynolds number product.. That's just physics.. but I'm more concerned about fact that I cannot recreate same condition and have same effect of broken wings.. so we all can learn something from this case. Now it looks like an anomaly in game.