Why do my wings keep breaking?

[GGTharos]

I believe you're right. I'm looking up the BAL for your loadout right now - check excerpts from -1 attached here. How much fuel were carrying?

Edited July 27, 2011 by GGTharos

[Snoopy]

Realworld our pilots never use speedbrakes on gun runs....

[Phuz]

The wings are snapping off as a result of g-loading and not necessarily airspeed.

 

Increased airspeed, however, when combined with an equal amount of aft-elevator input on the stick will result in higher g-loading. A 50% aft input on the stick results in the same elevator deflection at 200 kias as it does at 400 kias - the only difference is you're gonna be pulling exponentially more G's at 400 kias with that same input. (this applies only to the a10c, not necessarily other aircraft which may or may not have flight control modulation systems)

 

I did some testing and the flight model is very realistic in the way that structural failure is modeled. An A-10c with wings laden with the absolute heaviest ordinance encounter structural failure in this sim at about 3.5g. A clean A10C will encounter structural failure at about 7-8g. Also tested wings laden only on outboard hardpoints vs wings laden only on inboard hardpoints and as expected the aircraft with outboard stores only encountered structural failure first.

 

Strafing technique is going to change from one target to another. Some targets are in valleys, some are in the middle of a desert. Some targets are heavily armored, others are paper thin.. So you can't really apply one hard and fast rule to strafing, but you should always be aware that if your wings are heavy with ordinance there is an increased chance of them snapping under heavy g-loads.

[OutOnTheOP]

Not sure I follow the "as expected" regarding inboard versus outboard wing loads increasing the likelihood of wing failure.

 

If anything, I would expect heavy INBOARD pylons to increase the risk of failure. Think about it; in a high-G turn, the wings are at a high angle of attack and producting a LOT of UPWARD force in the form of lift (I know the lift vector can be in any direction, but let's just say they're providing upward force, for simplicity.) The fuselage, however, is NOT a significant lift-producing body on the A-10, and is therefore producing a lot of DOWNWARD force (in the form of inertia) right at the center of the wings. Therefore, what adds more stress to the wings: additional downward inertia right where there's already a lot of downward inertia, or adding downward inertia at the wingtips, which are producting a ton of upward lift and doing their best to pull themselves up and off the fuselage? After all, the greatest stress is right at the wing root, not at the weapons hardpoints (which are carrying 2000 pounds at best). Adding the extra weapons inertia further out on the wings just reduces the amount of torque they'd be applying to the wing spars at the root.

 

*edit* note this only applies to symetrical maneuvers; obviously the farther out from the center of rotation a store is, the more velocity it has in a roll, and therefore more inertia.

 

To make a short simile of it, what is more likely to collapse a bridge; a 100 ton weight right in the middle, or ten 10-ton weights spread evenly across the whole span?

[Phuz]

I really dislike when people say "think about it" as it implies that the other person hasn't put any thought into what they are saying. Even if someone is factually incorrect, they may still have "tought about it" before making their assertions. Anyhow its an overused cliche that is well past it's time, IMO.

 

Retested and again, still encountering wingsnap on a 42k lb A10 at ~7g with stores 1/2/3/9/10/11 and ~8g with 42k lbs with ords loaded on stores 5/7.

 

Stores used are gbu-10 on 5/7 and 99% fuel for "internal stations"

Stores used are cbu-97 on 1/2/3/9 and travel pod on 10/11 for "external stations" (100% fuel)

 

These two test vehicles weigh in within 14lbs of eachother.

 

Maybe it is incorrect programming, maybe it is flawed testing, but I've "thought about it" and this is how it seems to work in the sim.

 

Feel free to test the sim and share your results.

[Mosley]

I was messing around with it last night and it seems that most of the time im to focused on lining up that little dot up correctly and get going to fast. While messing with it i did notice on the default loadout they were poping off around 6-6.5g's which i believe is around what paul said.

 

You guys lost me a lil on the above post, but it almost seems when pulling up the g forces are exponential as the speed increases. For example at 225kias i can pull as hard as i want and not hit the higher g's, but at 375kias 1/3 of the pull results in much higher g's and if not carefull you do the job for the enemy. Also i belive it is simulating a blackout from the g's but normally doesnt last long becase the wing is gone.

[Arclight]

Had that happen once. As a result I never do gun runs while hauling ordnance anymore. Launch everything else first, then switch to guns. Hasn't happened since. :joystick:

[Hanzales]

I didn't broken my wings (yet) :) Maybe after I saw video bellow (it was before my first flight) I can fly much more.... like with a mass, not just with textures and polygons.

 

Anyway in case it wasn't mentoined before, I'd like (very like) to see at least visual G-Force blackouts and deep breathing effects. It would be awesome:thumbup:

 

Edit: well seeing it again, I am really missing track IR so much, especially for maneuevres and orientation points. Also in case there are black outs above high G's I didn't archieved them because of that video :D Mainly check time 6:40. I thing that wings suffered the most force there, well after 4:00 HI "G" turn. I did that "break" above ground last time, survived and it was great :)

 

Edited July 27, 2011 by Hanzales

[Malexa]

Had that happen once. As a result I never do gun runs while hauling ordnance anymore. Launch everything else first, then switch to guns. Hasn't happened since. :joystick:

 

I am doing my gun runs as usual. Even with stores armed. Haven't had the pleasure to lose my wings due to over-G for quite a while now. I did not notice any difference to other versions. Maybe it is because I lost 'em so often in the past, that I am over sensitive to the G meter. Of course I alter my approach angel during gun runs while being heavy. Same for egress.

But on a second thought, even during an emergency maneuver, the wings kept in place today.

[OutOnTheOP]

Phuz, I said nothing about the behaviour in-game. I'm absolutely certain you're correct, and IN-GAME the outer hardpoints induce failure earlier. I am equally certain that I don't have the slightest inclination to waste my time conducting multiple tests of the theory.

 

And I'm terribly sorry for requesting that you ponder the point I was making in addition to your "expected" results. Perhaps what you should THINK about is the possibility I was not implying you had not thought about the issue, but should ponder an alternative view I presented. Would you prefer if I'd thrown in a "selah" instead?

 

Also, being an ass hat about cliches makes you easily as rude as the one who made a cliche. The one making the cliche is typically not INTENDING to be a douche. The one making elitist comments about it is FULLY intending. End rant.

[EtherealN]

OutOnTheOP:

The reason that outboard stores cause a greater risk of structural failure than inboard stores is that their mass acts on a longer arm. To put it in more everyday circumstances:

 

Take a fishing rod, affix a 1 hektogram weight right in front of your hand. Swing the rod. Nothing much happens. Now affix the same weight at the tip and swing the rod - then go buy a new rod. :)

 

The wingtips, in symmetric flight, do not produce any extra lift due to their position. (They might due to other things like having a different aerofoil profile, but that's separate.) The reason why a wing tends to flex up higher than the inboard is, again, that it acts on a longer arm giving it a greater capacity to counter the stiffness of the wingspar.

 

Another illustration: balance a 6 meter long plank on a centrally placed support. Hang heavy weights close to the support - nothing. Hang them at the outer tips... snap. Same thing in the case of your bridge - when you placed your weights on the centre, you maximised the arm of the load since the bridge is secured at the "tips", not the centre, as is the case with an A-10 wing.

Edited July 28, 2011 by EtherealN

[OutOnTheOP]

Aye, but the moment of force of the wing producing lift, and the stores, acting on inertia, are in OPPOSITION, not in concert. Heavy stores at the wingtips are an issue in rolling maneuvers because of the same forces you mention in the fishing-rod example, but they should actually HELP in an over-G: the wing is producing lift force that will torque the wing off the fuselage, which is "trying" to keep flying straight under inertia. The stores on the hardpoints are doing the same thing: trying to keep going straight under inertia. So while the wings try to pull themselves up off the fuselage, the wing stores "hold down" the wings. Your plank example ignores that there is a force pushing the opposite direction of the heavy weights. If it were a matter of an overloaded A-10 sitting on the tarmac with too much weight under the wings, sure... heavy weights further from the fuselage are worse.

Edited July 28, 2011 by OutOnTheOP

[EtherealN]

the wing is producing lift force that will torque the wing off the fuselage, which is "trying" to keep flying straight under inertia. The stores on the hardpoints are doing the same thing: trying to keep going straight under inertia.

 

So is the wing. ;)

[OutOnTheOP]

Sure, but all that high speed airflow has other ideas. The wing doesn't break down because of inertia, it breaks up because of aerodynamic stress. If it was all inertia, there would BE no wing breaking... the fuselage and wing would both just continue intact... in a straight line.

[Arclight]

I am doing my gun runs as usual. Even with stores armed. Haven't had the pleasure to lose my wings due to over-G for quite a while now. I did not notice any difference to other versions. Maybe it is because I lost 'em so often in the past, that I am over sensitive to the G meter. Of course I alter my approach angel during gun runs while being heavy. Same for egress.

But on a second thought, even during an emergency maneuver, the wings kept in place today.

To be honest, I was averse to making high-speed runs before I had a wing snap off. The A-10 is a lot more nimble without the wings being loaded down.

 

The time that wing snapped off I had a TER with 2 mavs on each wing. Not surprisingly, it proved to be a bit too much... It's all fine and dandy on the range, but when you see the flashes of a ZU-23-2 sending a warm welcome your way, it's all too easy to pull just that little bit too hard.

 

Friend of mine was "kind" enough to capture it actually. :doh: