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

[Vitormouraa]

Maneuverability has nothing to do with this. It's very agile at LOW speeds, but negative relaxed stability comes at a price: high wing load. The limiter serves a purpose.

 

I sometimes think people just fly the wrong way. Always turn as hard as they can, pulling 2-digit g's, flying Mach 1.6 at 45k and jump-snipe on bandits. With some brain work you can easily reduce stress on pilot and airframe. But then again online competitive is always about kill/death ratio so people just jump into the pit, burn towards bullseye, drop their tanks, spam some missiles and then burn home. It seems no-one - or at least only a few - actually try flying responsively. It's the arcade mind in a simulation environment that stops you from improving.

 

900km/h is really easy to blackout the pilot. Imagine at Mach 1.6.. I think you got me wrong mate.

[Jester Darrak]

900km/h is really easy to blackout the pilot. Imagine at Mach 1.6.. I think you got me wrong mate.

 

But g-loc is not the issue here. Your "pilot" can sustain around 7-7,5g, if you black out at 900km/h you're definetly doing something wrong.

[Vitormouraa]

But g-loc is not the issue here. Your "pilot" can sustain around 7-7,5g, if you black out at 900km/h you're definetly doing something wrong.

 

What I meant is, at 600km/h, if you pull the joystick till G-lock isn't so easy. At 900km/h it's easy if you let the pilot get blackout. I'm not saying it's the issue, you are saying. I was just saying the people sometimes think it's not real break off the Flankers wings. And I didn't say I'm getting G-lock at 900km/h, I said it's EASY TO GET G-Lock.

[Jester Darrak]

Yeah, that's basically what I'm talking about. But it's also easy to avoid g-loc and even breaking your wing if you plan ahead a bit. But lots of people play this sim with what hollywood told us in mind. And then GGTharos wastes his time to prove them wrong.^^

[Stuge]

It's the arcade mind in a simulation environment that stops you from improving.

Improving is a very subjective concept :)

[JazonXD]

gonna just leave this here:

[ame]

[/ame]

 

was toying around and ripped only one wing off. i managed to crash land. i think ED needs to focus on their landing gear modeling here :D

[HiJack]

gonna just leave this here:

 

was toying around and ripped only one wing off. i managed to crash land. i think ED needs to focus on their landing gear modeling here :D

My god, you created a forest fire man! :lol:

[JazonXD]

My god, you created a forest fire man! :lol:

 

Hahaha, that's the least of my worries!

[DarkFire]

gonna just leave this here:

 

was toying around and ripped only one wing off. i managed to crash land. i think ED needs to focus on their landing gear modeling here :D

 

Very impressed that you managed to get that bird down in (most of) one piece! Surprised you didn't jettison the stores on the undamaged wing though - that might have reduced the differential lift a bit. Damned good piloting nonetheless :thumbup:

[Winston60]

gonna just leave this here:

 

was toying around and ripped only one wing off. i managed to crash land. i think ED needs to focus on their landing gear modeling here :D

:thumbup: How did you incur that damage? Was it stress or combat damage?

 

I'm surprised the tires didn't blow. I can blow tires on the taxi way now just by being heavily overloaded and hitting the brakes for too long.

[Redacuragsr]

This might have been discussed here already, so I apologies if I'm asking it again. How come the wings on the flanker break off all of a sudden when doing high g turns, wouldn't the piolet black out first, so that would be your indication that you are pulling to many g's, however in this case the wings just break off without any indication of a pilot going into g lock. Does that mean the piolet can sustain a higher g load than the plane? That's what seems strange to me, or am I missing something?

[GGTharos]

The amount of g you can safely pull is reduced as the gross weight increases. A fully fueled and armed flanker may have a safe g limit of just 6g, which could cause you to break the wing at around 8g, depending on implementation details. Under these circumstances you will break the aircraft before the pilot blacks out.

[Redacuragsr]

Thanks for the explanation GGTharos. I guess that makes sense, I always assumed that the plane was designed to be more capable than the piolet even with a full combat load.

[GGTharos]

No problem. I also didn't realize the Su-27's g-load limit is like this, it was a bit of a surprise to me.

 

BTW, there's another case where you may destroy the aircraft without blackout:

 

If you flash high g (for example, let's say 10g) but you don't break the aircraft, it reduces the safe g-load limit. So suppose your limit was 8g, you flashed 10 for a couple of seconds (so your pilot shows no signs of black-out), now you're at 6g safe load limit because you over-stressed the airframe (I made these numbers up for the example)

[probad]

I always assumed that the plane was designed to be more capable than the piolet even with a full combat load.

 

it's more a misunderstanding that max load = combat load.

 

"full combat load" is not 71000lbs!

[JazonXD]

Very impressed that you managed to get that bird down in (most of) one piece! Surprised you didn't jettison the stores on the undamaged wing though - that might have reduced the differential lift a bit. Damned good piloting nonetheless :thumbup:

Thank you! Thought of jettisoning the stuff never came across my mind - i was slightly busy haha! Although i think that would have upset the balance even more and cause the whole plane to tip in the side of the broken wing. The flanker has more than enough power to keep it flying unlike slower aircraft so i'm not worried about the extra weight in total.

:thumbup: How did you incur that damage? Was it stress or combat damage?

 

I'm surprised the tires didn't blow. I can blow tires on the taxi way now just by being heavily overloaded and hitting the brakes for too long.

 

i was flying and testing the plane, I flew really fast and made a left turn at 85 degree bank angle and even with the G limiter ON, it pulled just enough Gs to break off the left wing.

 

And yes, I was also surprised that the wheels didn't get destroyed when using the breaks for more than like 1 second on the runway will cause it to burst. When i touched down, i was desperately trying to open the parachute, but i guess it doesn't work on the grass. You can see the canopy of the parachute opened from the external view, but no parachute dragging out of it.

[Redacuragsr]

If you flash high g (for example, let's say 10g) but you don't break the aircraft, it reduces the safe g-load limit. So suppose your limit was 8g, you flashed 10 for a couple of seconds (so your pilot shows no signs of black-out), now you're at 6g safe load limit because you over-stressed the airframe (I made these numbers up for the example)

 

I assume that holds true for other aircraft as well, the g-load limit being reduced that is...like the f-15 for example. I noticed a couple of other strange things after the last update though (Well may be they are strange), I was flying fully loaded at around 900 kph when I executed 30 degree left bank without even pulling back on the stick yet and lost my left wing, so if you are just banking to one direction is there supposed to be a possibility of loosing a wing as well? also (and i know this is not related to this thread)but while flying the P-51D I was trying to do everything possible to break my wings, but couldn't do it after this update, i remember from flying this aircraft before that it wasn't too hard to do it before. To be fair its been a few months since i flew the mustang though so not sure if its the last update, but can't help to think that it could be related to the update. Just wanted to put it out there. Thanks.

[GGTharos]

I assume that holds true for other aircraft as well, the g-load limit being reduced that is...like the f-15 for example.

 

Nope. They are not the same aircraft. The F-15C has a very high BAL at all weights. You're not going to break it and more to the point, you're just not even likely to pull enough g's to bring it anywhere near to taking serious over-g damage. It's not that possibility doesn't exist, and there should definitely be some extremes that are programmed in for this, but you're just very unlikely to encounter them IMHO.

 

There's one account of a real F-15 being subjected to 12.5g for a good amount of time. It had to be written off after it was landed AFAIK, but there is also a lot of history of pilots flashing 10g and on much more rare occasions 11 and 12-ish, and those aircraft were usually returned to service. In general what'll happen to an F-15 in real life is that you'll shorten it's useful life time - ie. an airframe designed for 8000 hours of service might be worth 7500 after an over-g (numbers made up for the example).

 

It's possible that the effects on the Su-27 might be a bit too harsh, but, on the other hand, if you do the analysis it doesn't appear to have been designed as a 9g fighter at all: It's long wings, large airframe and weight are a trade-off. To make it stronger than it is would have meant making it even heavier.

Instead, it can be flown at reasonably high g in it's combat envelope (IIRC 52% fuel and 4 missiles), and it's over-g warning system appears to be tuned to that configuration. That Su-27 is as heavy as an eagle with full fuel, full complement of missiles and probably about half an external fuel tank's worth of fuel as well. To me, this is an indication that I should plan to be flying the flanker in combat within those basic parameters, where I suspect most people expect to fight it with full fuel and full complement of missiles.

 

By contrast, the F-15C seems to list a BAL of 9g at all weights and has demonstrated the ability to flash a lot of g in training and in combat.

 

Different airframes, different design, different trade-offs. So, you know have a flanker that can't do things it wasn't design to do: 30g magic s-key turns, or full-up fights at maximum gross weight. It still tears things up in it's favorite combat envelope, having good thrust and excellent turn rates.

 

I noticed a couple of other strange things after the last update though (Well may be they are strange), I was flying fully loaded at around 900 kph when I executed 30 degree left bank without even pulling back on the stick yet and lost my left wing, so if you are just banking to one direction is there supposed to be a possibility of loosing a wing as well?

 

That could be a bug, or perhaps you over-g'd the aircraft before? Without seeing the history of the flight, can't really tell.

[mvsgas]

I assume that holds true for other aircraft as well, the g-load limit being reduced that is..

The g limit was not reduces, it was finally implemented on the SU-27. I have broken the wing on the A-10C, SU-25, 25T, F-86, P-51 and now the 27.

[SinusoidDelta]

I assume that holds true for other aircraft as well, the g-load limit being reduced that is...like the f-15 for example. I noticed a couple of other strange things after the last update though (Well may be they are strange), I was flying fully loaded at around 900 kph when I executed 30 degree left bank without even pulling back on the stick yet and lost my left wing, so if you are just banking to one direction is there supposed to be a possibility of loosing a wing as well? also (and i know this is not related to this thread)but while flying the P-51D I was trying to do everything possible to break my wings, but couldn't do it after this update, i remember from flying this aircraft before that it wasn't too hard to do it before. To be fair its been a few months since i flew the mustang though so not sure if its the last update, but can't help to think that it could be related to the update. Just wanted to put it out there. Thanks.

 

Need to know what the conditions were when the wing failed to make a guess. Draw a free body diagram of an aircraft performing an aileron roll. The aileron forces are in opposite directions, one force acting up and one acting down. The summation of all moments acting on the airframe in a roll are the aerodynamic moments, change in drag force (not really relevant in this case), and mass moment of inertia multiplied by roll rate. So short answer, yes its possible and becomes more possible with higher mass, higher roll rate, higher speeds, lower altitudes, etc. Considering you were fully loaded, a fast roll command induces a large asymmetric load. I don't have the knowledge to say whether the the shear force would be large enough to snap off the wing of a flanker. Someone more intelligent (and with very specific details of the flanker's design limitations) would have to chime in...

Edited April 13, 2016 by SinusoidDelta

[Redacuragsr]

Figured out the p-51 problem...immortal setting Duhhh

 

Interesting theory about the F-15, but strange because first of all the flanker was designed second and to take on the f-15 so I would think the Russians would design it with the characteristics of the 15 in mind (if they were fully known of course at the time) In fact when they build the first prototype the main engineer decided to scrap the project and go back to the drawing board because it could not match the known characteristics of the 15.

 

Why is it not likely that the F-15 will pull enough g's to bring it anywhere near to taking serious over-g damage? Is it because of the FBW limits? Or is it because it is a BVR fighter so it has no need? Theoretically speaking wouldn't the flanker reduce it operational hours as well by pulling high G's but not necessarily break its wings, other wise you would pretty much have a fleet of planes that are useless if piolets break the g limits for a few secs. I think that the laws of physics apply to all the planes equally (with some adjustments of course for structural design).

 

regarding the s keys and the 30g turns, well yea that is pretty ridiculous and would definetly do some damage. From what i remember from playing BMS the F-16 and even the mirage both have a FBW over ride switches for extreme situations, not sure if the 15 does or not, but it seems that it probably would have something similar as well, in which case it should be able to break a wing also IMHO ofcourse.

[SinusoidDelta]

The F-15 is not FBW. It is hydraulically boosted, augment controls. The f-15 has good static stability characterstics (without augmentation or CAS). The Flanker does not exhibit steady static stability (s key pressed) It may be counter intuitive but that is an advantage in the sense that it allows for much more maneuvarability when under control of the FLCS. The down side is the topic of this discussion essentially. You can overload the jet much easier.

[Winston60]

........i was flying and testing the plane, I flew really fast and made a left turn at 85 degree bank angle and even with the G limiter ON, it pulled just enough Gs to break off the left wing......

So it is possible to bend/break things instead of a catastrophic "off with the wings" event? Perhaps the Su-27 damage model programming could be tweaked for more instances like this as an alternative to the "instant disintegration"? :dunno:

Edited April 13, 2016 by Winston60

[Ironhand]

Thank you! Thought of jettisoning the stuff never came across my mind - i was slightly busy haha! Although i think that would have upset the balance even more and cause the whole plane to tip in the side of the broken wing...

Had the same situation yesterday while trying to tear the wings off this butterfly. Half a wing snapped and had to land it. Jettisoning the weapons helped--also not my first thought, more like 3rd or 4th--after seeing what kind of control I had and figuring out where to try and put it her down. Getting them jettisoned was problematic because of the yawing forces involved--never could get the last one off. The aircraft did seem a bit easier to control after that, though.

 

When i touched down, i was desperately trying to open the parachute, but i guess it doesn't work on the grass. You can see the canopy of the parachute opened from the external view, but no parachute dragging out of it.

Your chute opened and blow out because of the excessive landing speed. That's why the cannister was open but no chute was showing. It opened for me on the grass without a problem.

[Azrayen]

gonna just leave this here:

 

was toying around and ripped only one wing off. i managed to crash land. i think ED needs to focus on their landing gear modeling here :D

 

Had same wing failure 2 days ago.

Managed to land. Taxi. Take Off again (for fun). Land again.

No worries.:D