No more above 12G turns

[DarkFire]

OK, well this is going to be my project for the weekend. :book:

 

I can't speak or write Russian - could someone ask Flanker if he/she wants anything in particular?

[SinusoidDelta]

I've can't even pull 14G in the eagle. Is it even possible supersonic to pull that many G with three bags with our F-15 FM? I don't think so. The F-15 is capable of extreme overloading without exceeding ultimate strength. We can't even over-g the f-15 to the extent that should be possible. Consider attempting to simulate what structural members might yield and what plastic deformation would result, simulating the resultant deformation's aerodynamics effects...it becomes an absurdly complicated task.It's unfortunate that the published Su-27 flight manual has laid out overload limits and complete structural failure is the only result but that's how it is..... Until ED gets first-hand information to the contrary we know it's not gonna change.

[Frostie]

I've can't even pull 14G in the eagle. Is it even possible supersonic to pull that many G with three bags with our F-15 FM? I don't think so. The F-15 is capable of extreme overloading without exceeding ultimate strength. We can't even over-g the f-15 to the extent that should be possible. Consider attempting to simulate what structural members might yield and what plastic deformation would result, simulating the resultant deformation's aerodynamics effects...it becomes an absurdly complicated task.It's unfortunate that the published Su-27 flight manual has laid out overload limits and complete structural failure is the only result but that's how it is..... Until ED gets first-hand information to the contrary we know it's not gonna change.

Initial turn at supersonic was 12G

 

[Martillo1]

Initial turn at supersonic was 12G

 

Well, that's a smack in the face. More than 17 G!

[*Rage*]

F15 can midair and land with one wing in real life. 17.9G with 3 bags and full load ain't no thing but a chicken wing.

[Ktulu2]

Were the bags empty of full? I remember reading that in training a 15 was broken due to pulling 9Gs w/ 2-3 bags.

[Frostie]

Were the bags empty of full? I remember reading that in training a 15 was broken due to pulling 9Gs w/ 2-3 bags.

 

Full, the only way to add more weight would be putting some AIM-54s on, i'm sure it would handle that also. :)

[SinusoidDelta]

I stand corrected. How long did it sustain 17G for? I'll have to try it out although flying with 3 bags is likely to get you killed by the enemy before you rip your jet apart.

[kobeshow]

I think F-15 pilots are so used to 3 bags + full burn that they don't realise the strain they would put on a real plane if they flew it like that, but the G load on the HUD has a display limit of 9.9 so they probably think it's fine (;

 

Snarky remarks aside, hopefully all FC3 planes get some type of structural integrity.

[IASGATG]

Again, it should be noted that the safe structural limit for the F-15C with 3 bags at supersonic is still 9g.

 

I can also say that I've never pulled more than 14g in the F-15 in 5 years of flying. I'd be curious to see the track to see how you made the eagle pull that hard? I assume you turned off the entire CAS and did and inverted snap pull?

[*Rage*]

I also never pulled any Gs in the Su27 until the damage model was implemented. It was only it was updated that I realised that I often did. Im sure if a damage model was implemented for the F15 also many pilots would be surprised what they regularly spiked.

Edited May 13, 2016 by ///Rage

[*Rage*]

Full, the only way to add more weight would be putting some AIM-54s on, i'm sure it would handle that also. :)

 

F15 FM FTW!

Edited May 13, 2016 by ///Rage

[GGTharos]

People who's way of flying is lateral g at full stick deflection while supersonic in a dive with 3 bags, yes.

Had to really go out of your way for that one, so I have to wonder just how surprising it would be (but I have no objection to that surprise :) )

 

In any case, this shows another bug: This amount of g should not be physically possible to pull; the hydraulics shouldn't be capable of supplying enough pressure to deflect the stabs this much. 12.5g is the most, max-stick-deflection g recorded in an F-15, and it was about 10000lbs lighter.

 

I also never pulled any Gs in the Su27 until the damage model was implemented. It was only it was updated that I realised that I often did. Im sure if a damage model was implemented for the F15 also many pilots would be surprised what they regularly spiked.

[Martillo1]

People who's way of flying is lateral g at full stick deflection while supersonic in a dive with 3 bags, yes.

Had to really go out of your way for that one, so I have to wonder just how surprising it would be (but I have no objection to that surprise :) )

 

In any case, this shows another bug: This amount of g should not be physically possible to pull; the hydraulics shouldn't be capable of supplying enough pressure to deflect the stabs this much. 12.5g is the most, max-stick-deflection g recorded in an F-15, and it was about 10000lbs lighter.

So, if I have understood well, there are no G caused breaking effects implemented in the F-15 due to the assumption that it could never reach those limits due to the limits of hydraulic actuators. Therefore a bug in these, allowing them to full deflect, make the aircraft to pull insane G's without consequences.

[IASGATG]

"Insane G" = 18g for a fraction of a second in the most forced and unrealistic maneuver possible. In light of a month ago the Flanker being able to reliably pull 40g sustained for 2 seconds. :^)

[Frostie]

"Insane G" = 18g for a fraction of a second in the most forced and unrealistic maneuver possible. In light of a month ago the Flanker being able to reliably pull 40g sustained for 2 seconds. :^)

 

No, in light of this is what happens to a Flanker at 8-9g with half a tank of fuel and no weapons.

Eagle did 18g performing a flick roll and can always pull 14g in a turn, both with 3 full bags and a full payload.

 

[IASGATG]

Applying the same 50% error margin that the Flanker has, the F-15 is at least 13.5G max limit at all weights, speeds and altitudes.

 

Eagle > Flanker

 

#SorrynotSorry

[Frostie]

Applying the same 50% error margin that the Flanker has, the F-15 is at least 13.5G max limit at all weights, speeds and altitudes.

 

Eagle > Flanker

 

#SorrynotSorry

 

So 18G with no effect on stores at least is all fine. :megalol:

[karambiatos]

Do we have an F-15 singularity now?

 

The thread is unfortunately is about the su-27s wings not being particularly attached to the rest of the plane very much.

Edited May 13, 2016 by karambiatos

[Ironhand]

No, in light of this is what happens to a Flanker at 8-9g with half a tank of fuel and no weapons.

Eagle did 18g performing a flick roll and can always pull 14g in a turn, both with 3 full bags and a full payload.

If I'm interpreting what I see on the Info Bar correctly, you were about 1.5 times beyond the max operational limit. So, in terms of how the sim currently interprets that, I guess it's not surprising it happened.

 

What the F-15 does or doesn't do is a completely different matter.

[Martillo1]

Well, we will see what happens when the F-15's hydraulic actuators bug is addressed.

[SinusoidDelta]

No, in light of this is what happens to a Flanker at 8-9g with half a tank of fuel and no weapons.

Eagle did 18g performing a flick roll and can always pull 14g in a turn, both with 3 full bags and a full payload.

 

 

What's your mach there when breaking the wings off? My math could be wrong but it looks like you're smack dab in the middle of the transonic trap. Are you pulling 9G at ~mach 1.00 in a bank? Because that's how you rip the wings off.

[Frostie]

What's your mach there when breaking the wings off? My math could be wrong but it looks like you're smack dab in the middle of the transonic trap. Are you pulling 9G at ~mach 1.00 in a bank? Because that's how you rip the wings off.

 

No doubt that over stresses the airframe, it was part of a comparison of what happens when you overstress particular airframes in DCS after you claiming a certain DCS airframe couldn't do 14g.

[SinusoidDelta]

I said I didn't think it could. I admitted I was wrong. You win.

 

We're getting nowhere here, like most every thread on this forum. The Su-27 is extremely vulnerable in the transonic region, the eagle is not. Each aircraft is not going to exhibit the same failure mode or design limitation. I don't know what either aircrafts' failure mode should be. We could attempt a discussion from an engineering based approach or everyone can continue slinging mud.

[JunMcKill]

Initial turn at supersonic was 12G

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You're right, it's impossible to the current F-15, to make this turn at more than 1300 km/h and 17Gs, and keep the ordnance and tanks in their hardpoints attached, not to mention the wing and fuselage stress