Su-27. Extreme G-loads... G=?

[DarkFire]

Translating the pertinent part your attachment:

 

 

 

Darkfire, this is what I was referring to in my previous statement.

 

Rich

 

Excellent, thanks very much!

 

Some weight data for the purposes of calculating max G:

 

100% fuel, no external weapons, 100% ammunition & expendables: 27,116 Kg.

 

50% fuel, 4xR-73, 2xR-27ET, 4xR-27ER, full gunpad: 24,942 Kg.

 

75% fuel, missile load as above & full gunpad: 27,292 Kg.

 

100% fuel, missile load as above, full gunpad: 29,642 Kg.

 

100% fuel, 36xFAB-100, 2xR-73, ECM, full gunpad: 31,596 Kg.

 

So as an example, if you're at cruise RPM (85%, normally produces ~0.95M clean or .85 with a high drag load) with a max bomb load, your structural maximum load will be all the way down to 5.4G.

Edited April 9, 2016 by DarkFire

[Ironhand]

...

 

So as an example, if you're at cruise RPM (85%, normally produces ~0.95M clean or .85 with a high drag load) with a max bomb load, your structural maximum load will be all the way down to 5.4G.

I suspect it's actually higher than that. We're talking about max operational G loadings. I know that, in my initial flight at 21,400 kg and keeping below M .85, I was able to exceed the recommended limit by up to 25% without any noticeable problem. Instead of the recommended 8 Gs, I pulled as much as 10.5 and the wings stayed on. :) I was surprised by the results given the OP's initial complaint but didn't have time to test further.

 

This morning I tried again at that weight (but faster airspeeds) and the wings stayed on up through 15.5 Gs in one instance and 16.5 in another. Another time I only made it to around 13 Gs. Those were the structural limits for my weight and airspeed and the manner in which I was maneuvering.

[DarkFire]

I suspect it's actually higher than that. We're talking about max operational G loadings. I know that, in my initial flight at 21,400 kg and keeping below M .85, I was able to exceed the recommended limit by up to 25% without any noticeable problem. Instead of the recommended 8 Gs, I pulled as much as 10.5 and the wings stayed on. :) I was surprised by the results given the OP's initial complaint but didn't have time to test further.

 

This morning I tried again at that weight (but faster airspeeds) and the wings stayed on up through 15.5 Gs in one instance and 16.5 in another. Another time I only made it to around 13 Gs. Those were the structural limits for my weight and airspeed and the manner in which I was maneuvering.

 

I guess that would make sense if the data in the table represents safe operational limits, whereas the airframe may or may not be capable of more, with the possibility of structural deformation etc as G increases over the safety limit.

 

I remember reading a book which included a section on the MiG-29 which explained that while the G-limiter is set to 9, the airframe can survive 12 or thereabouts. Obviously may be different for the Su but it would make sense for the operators manual to give max G figures that have a built-in safety margin.

[marcoacv]

I am very disappointed, it became a joke. The eagle continues arcade, the Russian missiles are worthless and how is the Su-33 and Mig-29, how much longer to fix those things. No, rather they spoiled the su27, limit the use of S in at most 600 or 700km / h. Or at least apply all these behaviors on all aircraft. At least Show some respect with us customers and fix this mess as fast as possible.

Edited April 9, 2016 by marcoacv
complementation

[Ironhand]

...Or at least apply all these behaviors on all aircraft...

I imagine they will. Hopefully the F-15 will get the treatment next.

[secret1962]

It's clear this has been put for a mp playability purpose.

Airplanes are usually designed to sustain a few more Gs than the operational max G-load. This margin is even higher in military aircrafts.

Also, going over this G-load does not mean 100 % broken wings, but rather permanent deformations of the structure.

 

I'd like some data (from the actual flight model code) on the modelling of this new feature.

 

eg. for the F-15

[ame]

[/ame]
Edited April 10, 2016 by BIGNEWY
1.3 Administrative actions against forum members are not subject to public discussion

[Vitormouraa]

Guys, this is just an upgrade for FC3 aircrafts. I'm pretty sure they will do the same with the Eagle. But let's be honest, before the update you could pull a lot of Gs without problems, now it is a bit more realistic. Of course, the Flanker is a bit more hardcore, with "less capacity of maneuverability", it still a Flanker, but now, you'll have to pay attention on what you are doing.

[Ironhand]

It's clear this has been put for a mp playability purpose.

Airplanes are usually designed to sustain a few more Gs than the operational max G-load. This margin is even higher in military aircrafts.

 

And you can get well over the operational G loadings already cited for specific weights and airspeed ranges. I've been able to almost double it. But you have to be careful about how you maneuver. You can't just randomly throw the aircraft around. In a way, it's not all that different from when the PFM was introduced. Just as back then, now you have to be more in tune with the aircraft.

 

Also, going over this G-load does not mean 100 % broken wings, but rather permanent deformations of the structure...

No but it does mean you now have a pretty useless aircraft....sort of like one without any wings. I'm thinking of it as modeling shorthand. :)

[secret1962]

No but it does mean you now have a pretty useless aircraft....sort of like one without any wings. I'm thinking of it as modeling shorthand. :)

 

That's a little too generic and exaggerated...

I have just stated some facts.

Don't blame it on me that quickly please. And not with that rude attitude. Especially when I haven't said anything wrong.

[Sweep]

It's clear this has been put for a mp playability purpose.

Airplanes are usually designed to sustain a few more Gs than the operational max G-load. This margin is even higher in military aircrafts.

Also, going over this G-load does not mean 100 % broken wings, but rather permanent deformations of the structure.

 

I'd like some data (from the actual flight model code) on the modelling of this new feature.

 

eg. for the F-15

(video)

 

 

EDIT: Funny because when I've reported the su-27 doing cobras up to 1000 km/h unrealistic they warned me and now 1 year and a half later or more they add this feature...

http://forums.eagle.ru/showthread.php?p=2223057

 

Is that an F-15A or C? The C had structural improvements, for example, a 9g design limit, instead of 7.33 like the original F-15As.

 

I wonder what the design/structural max G margin is on these things...I'm assuming 1.5, but I don't really know...

[Winston60]

Guys, this is just an upgrade for FC3 aircrafts. I'm pretty sure they will do the same with the Eagle. But let's be honest, before the update you could pull a lot of Gs without problems, now it is a bit more realistic. Of course, the Flanker is a bit more hardcore, with "less capacity of maneuverability", it still a Flanker, but now, you'll have to pay attention on what you are doing.

Not realistic at all. There's no warning sounds, no wing deformation, no creaking or groaning, just a sudden "off with the wings". Unless ED is trying to get people to avoid buying this module, some change has to be made to bring pre-wing loss warning and bent airframe damage into the game.

[Vitormouraa]

Not realistic at all. There's no warning sounds, no wing deformation, no creaking or groaning, just a sudden "off with the wings". Unless ED is trying to get people to avoid buying this module, some change has to be made to bring pre-wing loss warning and bent airframe damage into the game.

 

But this is FC3. Keep that in mind

 

Cheers.

[Ironhand]

That's a little too generic and exaggerated...

I have just stated some facts.

Don't blame it on me that quickly please. And not with that rude attitude. Especially when I haven't said anything wrong.

My apologies. No slight was intended. As I said, I'm thinking of it (the wings coming off) as modeling shorthand.

Edited April 9, 2016 by Ironhand

[GGTharos]

Is that an F-15A or C? The C had structural improvements, for example, a 9g design limit, instead of 7.33 like the original F-15As.

...

 

It was most likely an A but it's very difficult to find out that information.

 

In any case is funny that people are saying the f15 needs the 'same treatment' and 'it's arcade' when it has A) demonstrated it doesn't and B) you're highly unlikely to reach those limits with the aircraft as is in the game. There's a couple things to do but it's not going to be anything like the flanker.

People really don't know what they're talking about most of the time :-)

[Ironhand]

It was most likely an A but it's very difficult to find out that information.

 

In any case is funny that people are saying the f15 needs the 'same treatment' and 'it's arcade' when it has A) demonstrated it doesn't and B) you're highly unlikely to reach those limits with the aircraft as is in the game. There's a couple things to do but it's not going to be anything like the flanker.

People really don't know what they're talking about most of the time :-)

Assuming it's not already modeled, the "treatment" the F-15 might need is to have damage more likely to happen under continued excessive high-G maneuvering. It's not so much that the Su-27's wings come off, it's that they are more likely to depart at lower and lower G loads as you continue maneuvering. I've stressed the airframe to 12+ Gs, continued maneuvering at lower G loads and lost the wings at around 7 Gs. Tacview attached as example. Sorry, had to zip it to get it to upload.

[GGTharos]

Never been an issue on any F15C that didn't have defective longerons is what I'm saying :-)

There two aircraft are just not the same.

[RvEYoda]

We were flying a bit of guns and 2v2 today.. There seems to be something off with how the flanker behaves now...

 

We have all lost our flanker wings around what seemed like 6-8 gs repeatedly :P. No need to go up to 12+ Gs (up there it's guaranteed though). But it was like our 2v2 bvr session today when RvE-Dackster was turning back hot with his flanker... and his wings fell off :). I had the same problem myself when I tried to fly the aircraft.

 

In the end we all stopped using the su27 in bvr cause ... yeah... the wings just kept falling off.. There is something possibly wrong with the new damage behaviour ^^. And Im saying that as a person who is quite biased in the f15 direction. We need to be able trust our aircraft that our wings wont fall off at 7 Gs steady turn.. :)

 

EDIT: Ok in the track it actually shows Dackster @ almost 10gs when the wings break off.. I guess at least better than 7

Edited April 9, 2016 by =RvE=Yoda

[GGTharos]

What was the gross weight?

[dartuil]

Thats why I dont like su-27 and dont play it. Waiting 29 PFM.

[Ironhand]

Never been an issue on any F15C that didn't have defective longerons is what I'm saying :-)

There two aircraft are just not the same.

OK. So if I understand you correctly, if you get both the F-15 and the Su-27 to pull successive 10-12 G turns, the Flanker's wings will fall off (in real life sustain damage), while the F-15 won't.

 

We were flying a bit of guns and 2v2 today...

 

We have all lost our flanker wings around what seemed like 6-8 gs repeatedly...

You can get away with over-G-ing the aircraft for awhile as long as you are down around 21,400 kg gross weight. But 50% fuel and a full weapons load will give you 25,000 kg and it's a whole new ballgame.

Edited April 9, 2016 by Ironhand

[dartuil]

They said F-15C will have damage but not loose wing everytime?

As su-27 is more unstable than F-15 and mig-29?

[GGTharos]

OK. So if I understand you correctly, if you get both the F-15 and the Su-27 to pull successive 10-12 G turns, the Flanker's wings will fall off (in real life sustain damage), while the F-15 won't.

 

 

You can get away with over-G-ing the aircraft for awhile as long as you are down around 21,400 kg gross weight. But 50% fuel and a full weapons load will give you 25,000 kg and it's a whole new ballgame.

I'm saying you won't really have a lot of opportunities to be sitting around at 12g in an f15 one way or another, and flashing 12g is a non issue for that airframe. At least as long as you're not hauling the fuel tanks and cfts or something.

[*Rage*]

Never been an issue on any F15C that didn't have defective longerons is what I'm saying :-)

There two aircraft are just not the same.

 

Nor for the Flanker. Are there incidents of the wings falling off the Su27 in real life because of over-g?

 

The 27 damage model is based on the flight manual description. Just because you exceed its numbers does not mean it must disintegrate every time.

 

The F15 damage model on the other hand is non existant. You can pull as much g as you like as heavy as you like with the cas off and it will never break in game. The fact that an F15 survived pulling 30g or whatever and managed to land doesnt mean you should be able to do it in game with impunity.

 

Compared to the Flanker, the F15 is easy flight mode.

[Falcon_S]

...

 

Compared to the Flanker, the F15 is easy flight mode.

 

Something like that :thumbup:

 

+1

[Stuge]

Guys remember that Flanker needed this fix more urgently than does the Eagle. Surely Eagle's structural limit modeling will come later.. but you can't have everything at the same time!

 

So this is a definite improvement. It's a step towards better realism. You can't make everyone happy, and it may break apart a little too easy in some cases but still.. good job ED!