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View Full Version : For anyone who fly IRL, is negative G that difficult to make like in this game?



jermin122
05-06-2007, 12:24 PM
As we all know, to make a -G maneuver in IL2 is much more difficult than a +G. But all of the control surfaces of our A/C are splited. Theoretically, whatever positive angle you can make on elevator, you can make them negative. And there's nothing can prevent the plane to pitch down as long as the pilot can endure the red-out. I'v seen a cockpit video of modern prop aircraft on youtube and the pilot can do big negative G very easily. What's your opinion, RL fliers?

Stackhouse25th
05-06-2007, 12:33 PM
all pilots in game have a set health level.

Abbuzze
05-06-2007, 12:38 PM
Usual planes (no aerobatic) are designed to create lift upwards. So pulling up or flying with positive G, you are following this "upward" force. Pushing the stick foreward, you fly against this force.

Beside aiming with negative g is bad modelled in this sim - it is much to easy! You should only be hold by the seatbelts maybe you are not able to look through the gunsight because you will not be able to lower your head enough... and then also push the rudder...

Roblex
05-06-2007, 02:13 PM
What the game cannot model is just how disorienting Neg-G is.

If you take gliding lessons in the UK part of the very early training is to experience -ve G so you recognise it. The reason is that in the early days of winch launches every now and then a novice pilot would get to the top of the launch and instead of releasing the cable would stay attached and follow the arc all way down to a very high speed 'slingshot' crash; and this is despite having an instructor aboard. What was happening is that the novice was leaving it slightly late to drop the cable, experiencimg -ve G as the glider started to get pulled down again and freezing with the stick held forward. The instructors could not wrestle back control. Even today some gliding clubs saw off the stick in the front cockpit and re-attach it with a strong spring at the base covered by a brittle plastic sleeve so that in an emergency the instructor can pull his own stick hard enough to snap the plastic sleeve and regain control.

It is more than the light headed feeling you get on a roller-coaster, we are talking gravel stuck to the inside of the canopy! If you are not strapped in very tight you must also contend with the panic of finding your arse leaving the seat http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif Many WW2 pilots flew with loose straps because they could not reach everything if strapped in properly.

Also bear in mind that most modern light aircraft are not stressed for negative G maneouvres as high as even -1 G so few amateur pilots have experienced the real thing.

TX-EcoDragon
05-06-2007, 02:20 PM
Well, first of all, most things you will see on youtube are dedicated aerobatic aircraft which are designed to be more content in negative G flight. These are higher performance aircraft than any we have in the sim (excluding top speed from the equation) and they are more symmetrical too. Fully symmetrical airfoils, very light control forces, little to no dihedral (the v shape in wings), and very strong structures are what you will find in these dedicated aerobatic aircraft. Even in these aircraft, all but the highest level aircraft require more force on the stick when inverted than when upright for a given attitude or pitch rate. These aircraft also are usually able to withstand higher + g loadings than they can - because certain design compromises are made to give the aircraft its strength.

The warbirds we fly in this sim are designed to be more stable, and are optimized for upright flight. They have semi-symmetrical airfoils, lots of dihedral (see the pic in my sig and note that the wings are perfectly flat with respect to each other, and fully symmetrical in cross section), the wings are also mounted to the fuselage of the aircraft with a positive angle of incidence (meaning the wing is angled such that the leading edge is higher than the trailing edge), also the structures often cannot sustain the same loading inverted as they can upright, and may have reduced forward elevator travel. None of these things are good for inverted flight.

Now, of the warbirds in this sim the only one I've flown in the real world inverted for much time at all is the P-51, and it takes a healthy forward push on the stick, and I didn't do anything other than gentle inverted turns in it. . .could it do more? Certainly. . .but not very well, and it's not really nice to wring out these rare old birds. I have a few friends that fly a Buchon 109 and they reportedly have better inverted handling. Because of the fact that these are all vintage aircraft, and because it was not that common for a pilot to *want* to use much negative G, it's difficult to really say how each type really could perform with certainty. What we do know is that Hartman used negative G evasions in his 109 using something similar to an outside snap roll from an outside barrel roll. For most pilots though, whether their aircraft could do it or not, negative G wasn't too common as most found it rather unpleasant and they generally avoided it. If I were flying back then, I'd be using it though, at least for evasions. As has already been said, aiming, or tracking a bandit inverted isn't a simple affair, and in some cases can also jam the guns.

Oh and as to the red-out, that simply is a "sim-ism" which doesn't really happen, what does happen is some serious discomfort at elevated negative G loadings. Capillaries may burst, and perhaps some people have actually seen pink due to some blood in their eye, your lower eyelids may move up, and this may also cause a little pinkish vision, but I've never experienced any of these things, nor have I personally heard of others having any "red-out" and the type of flying we do leads to pushing many more negative G than any of these warbirds could manage. I guess it's good to have some sort of visual feedback when in negative G to attempt to simulate that feeling, but I'd rather it didn't come on so soon, it's a bit silly pushing over at 0G and seeing pink.

OneMug
05-07-2007, 12:58 AM
All replies make good points, esp the differences between regular civilian/war birds and acrobatic" aircraft.

When you are inverted, the stick throw is less effective. When you get full throw forward, you can't pull as many Gs as when pulling aft. Most a/c have a much lower negative than positive "structural failure" G limit. Either limit depends how strong the a/c is built, air speed and how fast the G is applied.

There's often stuff in the bilges (dirt, dust, and an occasional pencil or other small bit). That can fall "up" into your eyes, even with your helmet visor down, and onto the top of the canopy. They're cleaned out regularly but...

A squadron mate of mine, in F-8 Crusaders in Viet Nam, had a .57mm AAA round take out all three hydraulic systems as he was pulling out of a bombing run. When the UHT (Universal horizontal tail, called the "slab", which moves as one piece), loses hydraulic pressure, air flow causes it to go to the "zero" angle position This actually causes the F-8 go nose down, i.e., to pull negative Gs. Even tho' the a/c had its nose above the horizon out of the dive, we saw the plane make a big outside, negative G loop and crash into the jungle at a 135 degree inverted angle, killing the pilot He crashed just south of Khe San so wreckage was investigated. It was determined that the pilot was pinned so hard to the top of the canopy he couldn't pull either of his ejection seat handles. Good pilot, lucky hit, bad result. Bummer.

OneMug

Badsight-
05-07-2007, 01:15 AM
Originally posted by jermin122:
the elevator goes up as well as down , surely that means negative G should be as easy to do as positive G ? lmao

DKoor
05-07-2007, 02:18 AM
I just saw those crazy dudes, Red Bull racing team..... lolz0rz those guys make it regularly over 6G http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif
All kinds of maneuvers http://forums.ubi.com/images/smilies/59.gif

TheGozr
05-07-2007, 02:19 AM
Well different planes react very different in maneuvers there are no doubt about that, some get flat spots some oscille quicky some are dead stick like the early jet Mig's , if you go too fast the controls can be has hard as a concrete wall typical of mig 15/17 but anyway built a great tolerance to negative G's are extremely hard to have close to impossible. It is the hardest IMO. Some other effect that can turn you to blue is trying to move your stick at over speed in some planes.

Acrobatics planes are an other breed same with the old racers or new matter of fact

Think about it try to do some figures on a motorcycle and then take a bicycle and do the same . The bicycle is the acrobatic plane on that regard you will do things very quickly but it doesn't mean you will pull more -.+ G's it's all relative.

DKoor
05-07-2007, 02:40 AM
Originally posted by TheGozr:
Think about it try to do some figures on a motorcycle and then take a bicycle and do the same . The bicycle is the acrobatic plane on that regard you will do things very quickly but it doesn't mean you will pull more -.+ G's it's all relative. OK if I said something wrong then those people running that show are lying http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif
When they displayed from in-cockpit view, on the bottom of the screen was this figure of 6.8 G's or something that aircraft is currently doing.
Also confirmed by the narrator.

If you had watched it you would certainly noticed that http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

TheGozr
05-07-2007, 02:57 AM
You lost me there what exeptionel 6.8 G's is ? and sure is not pleasant..
Hell I pull 2.5 g's on my shifter kart.. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif.

DKoor
05-07-2007, 03:44 AM
Red Bull air race wrote: (http://www.redbullairrace.com/)
The Red Bull Air Race makes a much anticipated touch down in Monument Valley, Utah on the 11 and 12 May, for the third race of the season and the first U.S stop of the year. The dramatic scenery of Monument Valley Navajo Tribal Park will provide a breathtaking backdrop for the race which involves the world's best pilots navigating an aerial course at low altitude, flying at speeds of up to 400 kph and battling forces that can reach 10G. Read more...

Originally posted by TheGozr:
You lost me there what exeptionel 6.8 G's is ? and sure is not pleasant..
Hell I pull 2.5 g's on my shifter kart.. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif.

So I guess you know better than them, which forces they can pull, eh Gozr? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

WhtBoy
05-07-2007, 09:46 AM
Originally posted by DKoor:
So I guess you know better than them, which forces they can pull, eh Gozr? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

You're grossly misinterpreting what he said. His motorcycle/bicycle analogy is a good one.

His reply is to the original poster and he's trying to say that just b/c an aerobatic aircraft can maneuver quickly doesn't mean that a P-51 can do the same.

--Outlaw.

DKoor
05-07-2007, 10:02 AM
Originally posted by WhtBoy:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DKoor:
So I guess you know better than them, which forces they can pull, eh Gozr? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

You're grossly misinterpreting what he said. His motorcycle/bicycle analogy is a good one.

His reply is to the original poster and he's trying to say that just b/c an aerobatic aircraft can maneuver quickly doesn't mean that a P-51 can do the same.

--Outlaw. </div></BLOCKQUOTE>Thanks for correcting me!

Bremspropeller
05-07-2007, 10:15 AM
Even today some gliding clubs saw off the stick in the front cockpit and re-attach it with a strong spring at the base covered by a brittle plastic sleeve so that in an emergency the instructor can pull his own stick hard enough to snap the plastic sleeve and regain control.


WTF???