Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: Major Biggles on February 07, 2007, 05:03:40 PM
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HT, i was wondering how you've modelled the spit death stall. is it something that should happen, is it a bug, is it an unfortunate flaw in the spitfire?
it just seems awfully unrealistic, especially in the spit1. the plane just sits perfectly inverted, engine off...
surely a plane doesn't do that, even if it has no engine to pull it forwards, wouldn't the stabilisers point the nose down?
could you describe why the spit, and only the spit does that deathstall, especially the mk1 and 5? it's always puzzled me, it doesn't seems real... if it is a bug in the FM, are you aware of it?
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The spit is not alone. P38s can get into perfect float-down stalls as well. Mossies have been known to have unrecoverable, no-oscilation, perfectly flat vertical descents (as well as perfectly-still arse-first tail slides), and the Ta152... my god the 152... *shudder*
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mossie is bad, but nowhere near as bad as the spit1, it's just not right, a plane doesn't do that in real life, it should point the nose down no matter what you do with the controls...
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Definitely agree, with several planes that have odd stalls.
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Well, the Spit16 is prone to flat spins, but if you have a few thousand feet under you, you can recover. In comparison, you can push the Spit8 much harder without departing into a flat spin.
Mossie, some Spits, Bf 110, and the P-38s all suffer from this problem.
My regards,
Widewing
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Originally posted by Widewing
Well, the Spit16 is prone to flat spins, but if you have a few thousand feet under you, you can recover. In comparison, you can push the Spit8 much harder without departing into a flat spin.
Mossie, some Spits, Bf 110, and the P-38s all suffer from this problem.
My regards,
Widewing
it's not the flat spin that i'm referring to WW. it's the inverted float that i think needs fixing, i's not realistic. the spit1 has no chace of getting out of it because the engine cuts when you flip upside down, so you have no power to bring yourself out. the plane shouldn't do this anyway, the stabs would push the nose of the plane towards the ground, just like a weather vane.
it's that inverted flat spin float, that is most obvious in the spit 1 and 5.
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Originally posted by Major Biggles
...it's just not right, a plane doesn't do that in real life, it should point the nose down no matter what you do with the controls...
Might check your aerodynamics ;). What do you think happens in a flat spin or better yet, inverted flat spin in real life - especially the kind you can't recover from that kills people in real life? And without film and based on your descriptions I'm assuming that's what's happening.
One of the big issues with flat spins is that the angle of attack is very high (worst case at 90 degrees) which means you no longer have air travelling along the chord-wise direction of the wing which means that your rudders and elevators and possibly ailerons are rendered useless because there's no air flowing over them in the direction that they were designed to be used for. That's what makes flat spins so dangerous because you can be stuck in state that you can't get your plane "flying" again.
Here's an example of a real inverted flat spin done albeit on purpose by an acrobatic pilot in a stunt plane who can recover from it:
http://www.bulldogairshows.com/video/1997promo/flatspin.avi
I've done my share of flat spins and inverted flat spins in P-51's in AH. About 80% of the time I'm unable to recover. Usually they involve me hangin just a bit too much in the vertical intentionally or unintentionally. Here's a recent film of one where I screwed up trying to get ready to perform a hammerhead (use the film viewer and watch it from the external or fixed views - better with trail turned on as well) - note that once in a flat spin my rotation actually slows down dramatically which makes it seem like I'm just floating down upside down.
http://brauncomustangs.org/films/film61_flat_inverted_spin.ahf
Here's some info on the net regarding flat spins that's enlightening. The discussion regarding badly executed hammerheads and the result seem to describe my flat spin in the AH film above.
http://www.flyingmag.com/article.asp?section_id=14&article_id=699&print_page=y
I'm not a real life pilot so don't know all the ways you might try and recover from a flat spin but from what I've read one way to do it technically is transition it back to a normal spin and then recover using usual techniques. The trick is if you're able to get out of the flat spin into a normal spin with your nose pointed down. One trick is to deflect aileron in the direction of the spin.
Tango, XO
412th FS Braunco Mustangs
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Yeah Spitfire may be manuverable but if you spin it it's hard to recover. 109 and 190s are not that manuverable but getting out of a spin is easier in 109/190 than spitfire.
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There is NO spin in what he's talking about. The aircraft doesn't rotate around any axis. Take a toy plane, hold it inverted and horizontal, then move your hand toward the ground. There you have a sped up version of what happens in Aces High with these aircraft.
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I think this might be the same phenomenon (excepted from a post of mine in another thread... I was in a Spit V):
I fly out and there's a mountain range between our bases. As I approach I spot a NIK at about 7K. OK, I'll go get the NIK first then I'll go get Axer. This is going to be great! I'm chasing the NIK around the mountains, close enough to get a few pings on him but never close enough to bring him down. Suddeny: Ping Ping Ping and my left wing is gone.
My plane rolls over inverted and I know it's going to go down fast. I want every opportunity for the pings I landed on the NIK to become a kill for me and I can see friendly dots approaching so I shut off the engine.
Here's the strange part:
My plane floats gently toward the ground inverted at about the same speed as a chute. As I float there I watch the friendlies come in, engage the enemys, planes are flying all around me until the battle ends and everyone flys off and I'm just floating there upside down taking it all in.
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Originally posted by 1K3
Yeah Spitfire may be manuverable but if you spin it it's hard to recover. 109 and 190s are not that manuverable but getting out of a spin is easier in 109/190 than spitfire.
I have never gone into a flat spin or an unrecoverable stall in either a 109 or a 190.
110's yes, a pony, Yes, a mossie Yes
but never a 109 or 190
---EDIT---
At least not without having an important part of my plane shot off first LOL
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Originally posted by OOZ662
There is NO spin in what he's talking about. The aircraft doesn't rotate around any axis. Take a toy plane, hold it inverted and horizontal, then move your hand toward the ground. There you have a sped up version of what happens in Aces High with these aircraft.
If that's the case then give HTC the film. They're more than happy to look things over.
More than likely the aircraft transitioned from some form of flat spin to flat stall (where there is zero rotation around the yaw axis). Spins occur because the left and right wings of the aircraft are producing different lift in a stall because the variation of angle of attack between the left and right wings for a variety of reasons. As you near 90 angle of attack on both wings in a flat spin/stall it's conceivable that any spin is arrested by the natural directional (yaw) stability of the aircraft resulting in just a flat stall with little to no rotation around the directional (yaw) axis of the aircraft.
If you can't get your airplane out of this attitude, what you end up with is the airplane pancacking into the ground spin or no spin.
Tango, XO
412th FS Braunco Mustangs
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I used to have some bad ones in the KI84 that were unrecoverable. I sometimes held it in the vert too long & then floated down tail first. Shutting the throttle or the motor down had no effect. All the way down from 10k slowly, tail first. Very unrealistic. The weight of the engine should cause the nose to drop off like a lawn dart.
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Originally posted by 1K3
Yeah Spitfire may be manuverable but if you spin it it's hard to recover. 109 and 190s are not that manuverable but getting out of a spin is easier in 109/190 than spitfire.
Which would not be historically accurate.
The Spitfire Mk XIV (the massively over torqued one) had to be held in a spin or it would recover on its own after two or three rotations. Thus said Jeffery Quill, the Spitfire program's chief test pilot.
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Originally posted by dtango
If that's the case then give HTC the film. They're more than happy to look things over.
More than likely the aircraft transitioned from some form of flat spin to flat stall (where there is zero rotation around the yaw axis). Spins occur because the left and right wings of the aircraft are producing different lift in a stall because the variation of angle of attack between the left and right wings for a variety of reasons. As you near 90 angle of attack on both wings in a flat spin/stall it's conceivable that any spin is arrested by the natural directional (yaw) stability of the aircraft resulting in just a flat stall with little to no rotation around the directional (yaw) axis of the aircraft.
If you can't get your airplane out of this attitude, what you end up with is the airplane pancacking into the ground spin or no spin.
Tango, XO
412th FS Braunco Mustangs
Different aircraft display different behavior.... I've linked to a film I made of the Mossie, Spitfire MkI and the Bf 110G-2. When viewing the film, do so from the fixed view with trails turned on.
Strange Stalls (http://home.att.net/~ww2aviation/StrangeStalls.ahf)
My regards,
Widewing
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Originally posted by MajWoody
...Very unrealistic. The weight of the engine should cause the nose to drop off like a lawn dart.
You need to think through the physics. Most WW2 planes were designed to be positively stable. Planes have a center of gravity which the forces are balanced around in flight. Longitudal look at this means that the moment forces on either end of airplane balance each other out. Granted this usually means the forces in play as the the plane is in normal flight.
But really you don't have to go far to look at this. Again if the weight of the engine should pull the nose down all the time that means you would never have flat spins/stalls ever in real life. We know this isn't the case.
Tango, XO
412th FS Braunco Mustangs
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BTW - cool little film of a mossie pancake there WW :). I fly the Mustang exclusively so I only know about the nasty flat spins I get into with that bird.
Tango, XO
412th FS Braunco Mustangs
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Ok
For the flat stalls & spins I will have to agree with you but a tail slide all the way down to the ground from10 k, is this realistic?
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I don't think so. Even if you were somehow in the position where you were sliding arse-first downward, with no roll or oscilation, you've got one thing to get you out.
The rudder is biting directly into the airstream, like a knife, even. There's no way it wouldn't respond. Kick a little rudder and all of a sudden the air has a huge flat surface to slam into (the stab), and now you're oscillating and can get out of it.
That doesn't work in AH. I think it's a bug when it happens in here.
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Originally posted by dtango
Here's an example of a real inverted flat spin done albeit on purpose by an acrobatic pilot in a stunt plane who can recover from it:
http://www.bulldogairshows.com/video/1997promo/flatspin.avi
[/B]
Prove it. I see no recovery. HEHE
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I have not flown the Ki in about a year so I tried to reproduce it off line. The thing I didn't remember was that it was a spinning tail slide. I finally was able to get the nose down but it was too close to the ground to pull out.
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Originally posted by Krusty
I don't think so. Even if you were somehow in the position where you were sliding arse-first downward, with no roll or oscilation, you've got one thing to get you out.
The rudder is biting directly into the airstream, like a knife, even. There's no way it wouldn't respond. Kick a little rudder and all of a sudden the air has a huge flat surface to slam into (the stab), and now you're oscillating and can get out of it.
That doesn't work in AH. I think it's a bug when it happens in here.
Are you sure about that.
Imagine a parachute with a weight and rudder at one end. The rudder may oscillate a little bit it won't flip the chute over. Now think about the prop and the drag it produces in a tailslide.
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Why does an a/c stay in a flat spin?
"With adequate training an incipient spin is readily anticipated and easy to correct – provided the aircraft weight and balance are within the stated limits – but if the correction is not done before the nose has swung maybe 90° or so, it may develop into autorotation where the aircraft is descending in a stabilised nose down rotation – rolling, pitching, slipping and yawing at a constant airspeed at or slightly above Vs1 – a full blown spin with each 360° rotation taking only 3–5 seconds. The height loss during each rotation – 150 to 450 feet or more depending on the stall speed – plus the considerable height loss during the pull out from the recovery dive, is insignificant at a reasonable height but will be critical at lower levels. "
http://www.auf.asn.au/groundschool/umodule8.html#turns
Notice: "aircraft balance" If, for some reason, the weight likes to stay behind the center of lift, maybe because of rotational forces, the a/c could be impossible to recover until the rotation speed is decreased. It does eventually when the a/c hits the ground... But seroiusly getting out of autoration spin needs timing to counter the movement and getting into a favourable position to establish positive control force.
Same page: "Aircraft which tend to spin with the nose pitched well down will recover more quickly than an aircraft where the spin attitude is relatively flat. However if allowed to continue past two or three full turns then centrifugal forces become well established – which tend to make all parts of the aircraft rotate in the same horizontal plane – and a nose down spin may turn into a flat spin, which will then speed up rotationally and break-out will take longer, or may not be possible because it may be impossible to lower the nose. Engine power – and its associated effects – also tends to flatten the spin. The flatter the spin the closer the spin axis is to the cg and the greater the aoa, maybe 60° or more! Also at such angles the rudder may be completely blanketed by the fuselage, making that control quite ineffective. Structural stresses increase as the spin progresses. A flat spin might be induced if, at the point of stall, full opposite aileron is applied with full rudder."
Same page still: "Spin restrictions are not confined to non-aerobatic aeroplanes, for example intentional spins were prohibited in the Seafire 47 and Sea Fury, very fast naval fighters of the late 1940s early 1950s, because of the time to recover and the consequent extreme height loss."
Interesting. These are Griffon engined Spits but what wing? The newer wing with laminar flow?
"The Spitfire Mk XIV (the massively over torqued one) had to be held in a spin or it would recover on its own after two or three rotations."
To left or to right? It has the Griffon, right? If it is spun into the same direction as the Merlin engined it probably likes to straighten itself by torque alone. But what happens if it is spun to direction it naturally likes to spin...
-C+
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Another factor that I'm sure plays into the unrealistic behaviour of every flight sim I've ever played when it comes to modeling departed flight is that in real life, air isn't "perfect". It has localized movements, and layers of varying densities and tempuratures, etc.
But in the sims, we have perfect air. And if we have wind, we have perfect wind. It stands to reason that some events that are possible in sims "at the edge of the flight model" would be extremely unlikely in real life as a result.
In sims, if you hit upon the "ideal" balance of forces and conditions for some abherrant behavior, you'll have the same constant ideal conditions until you smacktard or manage to "break" the balance yourself.
Whereas in real life, the environment is constantly in change, so there is more of a chance that external factors would break the balance for you.
Grue
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Originally posted by Krusty
I don't think so. Even if you were somehow in the position where you were sliding arse-first downward, with no roll or oscilation, you've got one thing to get you out.
The rudder is biting directly into the airstream, like a knife, even. There's no way it wouldn't respond. Kick a little rudder and all of a sudden the air has a huge flat surface to slam into (the stab), and now you're oscillating and can get out of it.
That doesn't work in AH. I think it's a bug when it happens in here.
Read:...
Various things can go wrong with a hammerhead, including a tail slide if the pilot is late with rudder. If the airplane rotates about its spanwise axis, a startled pilot might suddenly apply forward stick together with the rudder and unwittingly set up the conditions for an inverted spin entry.
http://www.flyingmag.com/article.asp?section_id=14&article_id=699&print_page=y
Tango, XO
412th FS Braunco Mustangs
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some of you are confused about what i'm referring to. i'm not talking about spins, flat spin, high AoA stalls, or ANYTHING like that. the spit, and ONLY the spit, enters an inverted stall when you are moving slowly with flaps out, and you roll over the top of a rolling scissors and cut throttle slightly.
it turn the plane upsaide down and the plan drift straight downwards, lying perfectly still on it's back, 90 degrees to the vertical. it falls like that, no spin, nothing, just falls like a brick. in the spit5 the stall is just about recoverable if you have the altitude, as the engine doesn't cut and you can build up enough air over the controls to wriggle out.
in the spit 1 however, the engine cuts out so you have no chance at all of exiting this stall.
my point is:
this should not happen in either pane, the stall is not realistic, the stabilisers would right the plane, as it is travelling downwards. the airspeed on the stabs would act as it would on a windvane and puch the nose into the wind (straight down in this case)
perhaps it is this that is not modelled, the effect of the stabilisers when the plane is not moving (the plane moves down, but vertically upwards as it is inverted, if you understand what i mean). seeing as their is no forward motion, perhaps the game does not register any air resistance and the stabs have no effect?
HT, this is really a question for you, why is it that the spit does this? is it a bug? is it an unfortunate sacrifice in the spit FM? what's going on?
it would be great if i could get an answer to better understand why it does it so that i can avoid it. ideally, i would love it to be fixed, if it is indeed an error.
thanks HT :)
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Originally posted by Vulcan
Are you sure about that.
Imagine a parachute with a weight and rudder at one end. The rudder may oscillate a little bit it won't flip the chute over. Now think about the prop and the drag it produces in a tailslide.
No I'm not sure about it, but your parachute analogy isn't an accurate one. Most fighter aircraft in WW2 were well balanced. That is, they aren't very tail heavy and they aren't very nose heavy.
A parachute has all the weight at the very end, and is self-stabilizing. An airplane that is balanced around a central point is not going to self-stabilize in a tail slide, especially not if you kick rudder while it's biting into the wind.
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wouldnt the tail stab act like veins on on arrow?
More wind resitance in the back of the plane than in front, so the nose would be pushed down?
Arrows have a center of gravity, mid shaft.
Given enough alt (read or speed), they will always fly tip down.
I assume the same would be true in a plane.
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Originally posted by stockli
wouldnt the tail stab act like veins on on arrow?
More wind resitance in the back of the plane than in front, so the nose would be pushed down?
Arrows have a center of gravity, mid shaft.
Given enough alt (read or speed), they will always fly tip down.
I assume the same would be true in a plane.
exactly my point, yet the plane just sits inverted, 100% chance of death...
the stabilisers would point the nose down.
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I posted about the Spit I Upside Down Float To The Ground issue back during BoB 2006. I think I posted first in the BoB forum and then Shatzi or someone suggested I post in the Bugs forum. I did so and never got a response from HTC about it.
Your idea about the FM not recognizing the air traveling across the airfoils at 90degree from normal seems a likely reason but it is prolly more complicated than that.
I have got into this attitude many times in the Spit I and have NEVER been able to recover. I recall that there is a slight wobble in the pitch of the airplane with the stall horn going off and on but ther is no spin around the vertical axis.
I did SOME research online about spins in the Spit and never found even a hint of anything like this.
Jenks
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problem you are having biggles is flaps, having them deployed at the wrong time will put you in ths spin every time.
flaps are not needed in a spit anywhere as much as youd think when it comes to pucking the nose over in a vertical stall
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Originally posted by B@tfinkV
problem you are having biggles is flaps, having them deployed at the wrong time will put you in ths spin every time.
flaps are not needed in a spit anywhere as much as youd think when it comes to pucking the nose over in a vertical stall
flaps push you into it more readily, but i was able to put it straight into the stall in the MA, no flaps, you just take it up while slow and cut throttle as you're going over the top
but even if it was only the flaps, it's wrong, and should really be fixed, it's very irritating...
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NASA did some testing with spin recovery. The Grumman AA-1 had a laminar flow wing, and was found to be basically unrecoverable in a fully-developed spin. Notice the airflow strips on the wings during the spin, and the only solution NASA could come up with to get the plane out of it.
See the video here (http://www.grumman.net/gangster/NASAYankeeSpin.mpeg)
Notice that the relative wind as the plane descends does not "push" on the horizontal stab and force the plane nose down, even though I can assure you the plane is nose heavy. I own and fly one.
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Have you tried manual trimming the nose down as much as you can to help get out of your flat spin , stall ?
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stoney, there is no spin, the plane sits still, INVERTED, and floats to the ground. there is no spin, it just sits upside down. no plane falls like a brick upside down, else it would of course be a plane shaped brick, not a combat aircraft...
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To answer the original question, no it's not intentional.
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stoney, there is no spin, the plane sits still, INVERTED, and floats to the ground. there is no spin, it just sits upside down. no plane falls like a brick upside down, else it would of course be a plane shaped brick, not a combat aircraft
It's the same thing Biggles. What you are arguing about the details is somewhat equivalent of arguing semantics.
The term 'spin' points out to a plane which enters a state of aggravated stall. The loss of airflow diminishes all normal function of flight surfaces as they cannot effect the attitude of the plane in that state, and the plane starts a spinning momentum initiated by any variety of underlying causes including the angles of each of the roll/pitch/yaw axis, center of gravity, or torque.
The most frequent state of spin is witnessed when a plane stalls out during a dangerously harsh turn with high AoA and steep bank angle - the ensuing stall dips one of the wings, which subsequently results in a rolling motion while normall airflow is lost over the wings. Hence, the plane shows a continuous spinning motion in the roll axis while it falls nose-down towards the earth. Since in this case, the plane is falling nose down in a favorable AoA to the direction of travel, soon the airflow is somewhat recovered and the aileron starts working again. Thus a plane recovers pretty easily from this state.
However, in the case of the inverted flat "spin", the stall motion is aggravated as the plane goes belly up, the AoA is completely off from the plane's direction of travel, and soon the elevators and ailerons become useless as the plane starts a slow spin on its yaw axis which is initiated by torque. The stable nature of the plane with a good center of gravity now backfires - and the plane sort of reaches a new "equilibrium" in that new, belly-up state as it starts falling downwards. It effectively becomes a "frisbee".
The inverted flat spins of AH you mention, is exactly the same thing. Presumably, a slight difference between real life factors and in-game physics is the cause for the minmal difference in attitude. Whereas real-life inverted flat spin would show signs of a true 'spin' as the plane starts rotating on its yaw axis, the AH planes either do not generate enough torque or the momentum caused by the torque is somehow negated, and it falls inverted and flat, but no real sign of spinning motion except a somewhat oscillating motion both in the yaw and pitch axis while it falls flat. However, I personally have experienced a real inverted flat spin in some other planes, so the case might be purely situational.
The point is this, Major, I've never seen other sim games enter a warplane into a state like this. Others may have witnessed inverted flat spins in AW or WB, but personally, to me AH is the only game I've seen this happen. IL2 has a quite frequent case of normal flat spins in planes such as the P-38, but I've never seen an inverted state of a flat spin there. This "bug" in the flight model you claim, IMO, is actually a testament of how realistic the AH flight model is.
.....
One interesting tid-bit, is that there something greatly common with the list of some AH planes that show similar cases of inverted flat spins in the game.
The Mossie, some Spits, Bf 110, and the P-38s, Ki-84, Ta152 - these are all planes with a relatively large and flat wing/fuselage surface when viewed from top/bottom. Compare the ratio of the wings and the fuselage surface in these planes. All of them have a distinctively large and flat wings, as compared to a short or slender fuselage which is proportionately quite small to the wings. They are all excellent turning planes quite frequently pushed into extremes. They all have great elevator authority which allows them to pull high G turns at speed - which also means can be pushed easily into accelerated stalls by causing a drastic change in AoA while flying at high speed.
I don't exactly consider it strange to see them entering an inverted flat spin. Most usually these planes try to retain great speeds in the MA, as they are not the 'dragster' type of super planes and the only chance of shooting someone down is by aproaching with speed. Combine that with the fact that they have light elevator authority(except the Ki84) and an inexperienced pilot may very well pull the stick too hard during a steep turn. The AoA will go over its boundaries for normal flight and the plane will stall out. The bank angle is already high since it was in a steep turn - which means a stalling 'wing dip' will cause the plane to go inverted. The AoA freaks out and 'tumbles' the plane as it loses airflow. ?
(Although, in the case of the Ta152 and the Ki-84, the unrecoverable spins only happen due to a failed attempt to recover the plane's control in time when it has entered an elongated hammerhead)
It's not the type of stall they are showing that should be questioned. Rather, what is to be questioned is;
"Are those common factors in the above mentioned planes, really so effective that it is enough to cause inverted flat spins so frequently than compared to other planes?"
[EDIT/ps] Pyro posted right before me, but I can see his answers might be source for another confusion.
Pyro, by saying 'unintentional' what does it exactly mean? Does it mean;
a) The fact that only some of the mentioned planes entering "inverted flat spins" is unintentional
or
b) The FM portraying the "inverted flat spin" itself, is unintentional
??
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The original question was "is it something that should happen?", and the answer to that is "no, it's not intentional".
I would interpret this to mean that they didn't intend for the spit to do this.
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Short explaination: (or Executive Summary)
Just to clarify a few things here guys. All "spins" require yaw whether they be upright or inverted and the physics of upright and inverted are pretty much the same although the spins are not identical. There are no if's and's or but's about this. The bottom line is the inverted stall with no yaw described by Biggles isn't right, or as Pyro says, it's not intentional.
Spin 101: "or, how to say the same thing but in a lot more words":
There are different things that can cause a spin but all spins need two components: stall and yaw. If those two things don't exist there is no spin. There's another situation that many will call a spin and that's when you're very nose low and rolling but this is a high speed spiral, not a spin and there is no stall and only low yaw rates. The pilot keeps pulling on the stick but if he doesn't level his wings he just keeps tightening the spiral until he becomes one with terra firma.
Although the causes of a basic spin can be complicated it always starts out with a stall. If you don't stall, you can't spin. One wing stalls first (or is more stalled than the other wing) creating drag on that wing. The drag yaws the airplane toward that wing and the unstalled (or less stalled) wing generates a bit of lift which cases the plane to roll into the stalled wing. The roll increases the AOA of the stalled wing ensuring it stays stalled and keeps generating yaw due to drag while the roll decreases the AOA of the other wing ensuring the plane continues to roll so you have a self-perpetuating spin. If the airplane isn't recovered the yaw rate continues to build and generates more and more centripetal force causing the nose to rise toward the horizon. As the nose rises the yaw rate increases, roll decreases and the airplane enters a flat spin and you're in deep trouble in most airplanes.
How quickly or even if a plane will enter a flat spin is based on the mass distribution and CG. The more mass at the ends of the fuselage or wings the greater the tendancy to flat spin. Think of a gyroscope where the weight is almost all located away from the center at the rim. A flat spin works exactly the same way as a spinning gyroscope. The most violent and deadly spin is the high-speed "coupled departure". This occurs due to high rates in one axis generating high rates in another through gyroscopic precession, the two rates "couple" and you're off to the races. In this an airplane can almost instantaneously generate severe yaw rates resulting in a departure going almost directly into a fully developed flat spin. Airplanes have been known to come apart (engineers like to call this "structural divergence" while those with a more philosophical bent say "out of one, many". Pilots usually say "oh, sXXt") in a high-speed coupled departure.
The physics of an inverted spin are identical. You still have stall and yaw but the big difference is that the tail and rudder are now in the relative wind as opposed to being masked by the fuselage which means it's much easier to counter the yaw. Most inverted spins actually require the pilot to maintain pro-spin controls in order to maintain the spin otherwise most planes will recover on their own.
So much for Spin 101, back to AH. Biggel's description is accurate but it happens in other airplanes as well including the Hurricane. There is no yaw, hence, it is not a spin. A better term is a low-speed "departure" which is short for "departure from controlled flight". An even more specific description would be inverted pitch hangup or deep stall. There may be more but the only airplane I know of that displays a similar tendancy is the F/A-18 Hornet but even if there are a few more it's an extremely rare departure mode. Also, the Hornet does it upright, not inverted and it's related to a combination of it's flight control laws and the large leading edge extension (LEX) on both sides of the cockpit. It also doesn't fall straight down, it'll oscillate as in a falling leaf maneuver.
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Well it's definately a bug because it's happened to me in a Spit V with a wing blown off. Upside down floating inverted to the ground at the speed of a chute. You'd think missing a wing would make the plane roll over but nope.
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I thought it was against the F-18 NATOPS to fly the Hornet cross-controlled? :)
My only thought by posting the video was to counter the argument that the "relative wind" against the horizontal stab was enough to make the plane pitch forward. I was able to duplicate the condition Biggles discussed in the Spit I, Hurri I, and Spit V, although when I turned the engine back on, the Spit V corrected itself on its own. The P-47 would not do it, regardless of how uncoordinated I could get it.
Personally, I'm as curious to find out why it happens on these planes, and not others, given the overall precision of the stall model in the game, as shown by Skuzzy's post in WW's thread on the F4U and F6F.
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Originally posted by dtango
More than likely the aircraft transitioned from some form of flat spin to flat stall (where there is zero rotation around the yaw axis). Spins occur because the left and right wings of the aircraft are producing different lift in a stall because the variation of angle of attack between the left and right wings for a variety of reasons. As you near 90 angle of attack on both wings in a flat spin/stall it's conceivable that any spin is arrested by the natural directional (yaw) stability of the aircraft resulting in just a flat stall with little to no rotation around the directional (yaw) axis of the aircraft. [/B]
Nope. I'll film it when I have time. All I had to do was take a mossie vertical and force it to stay there until it slid like a leaf onto it's back and fell straight down and level inverted. I haven't done it in other aircraft because I never go straight up like that in fights and I don't fly any of the spits other than the 14.
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WW's film demonstrates the problem, even though he doesn't get the planes inverted. Its the same thing that gets 'em all kinked up going vertical.
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cool, pyro, thankyou ;)
i don't know how easy it is to fix the flight model of a plane, is it something that can be fixed without too much hassle?
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Originally posted by Mace2004
An even more specific description would be inverted pitch hangup or deep stall. There may be more but the only airplane I know of that displays a similar tendancy is the F/A-18 Hornet but even if there are a few more it's an extremely rare departure mode. Also, the Hornet does it upright, not inverted and it's related to a combination of it's flight control laws and the large leading edge extension (LEX) on both sides of the cockpit. It also doesn't fall straight down, it'll oscillate as in a falling leaf maneuver.
The F-16 has a deep stall that can be recovered by pitch rocking out of it. It can also occur inverted, and can be very smooth (non-oscillatory in pitch) and stable while in the deep stalled condition just like the Spitfire in this simulation. Or, depending on the configuration and entry conditions, the deep stall conditions can vary from smooth to highly oscillatory. Centerline stores tend to make the deep stall more oscillatory in pitch and depending on aircraft configuration, may cause the nose to slice left or right. I know of two F-16 simulations that model the deep stall and both only exhibit the smooth deep stalled condition similar to what we see in Aces High.
The type of deep stall that happens in Aces High can and does happen in real aircraft. Could it happen in the Spitfire? I'm not sure, but one of the cheapest ways to explore the question initially would be to build a simulation and see if it predicts that type of behaviour... HT already did, and it does. Is it right or wrong? I don't know off-hand, but it is interesting enough to investigate a little more. Perhaps HTC has discovered a previously unknown departure mode for the Spitfire?
Badboy
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LEARN TO FLY WITHIN THE LIMITS OF YOUR AIRCRAFT!
and for the love of pete stop :cry ing and :furious ing you whiners.
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Maybe it wasn't an unknown departure mode for the Spit. Just no one survived to discuss it.
Coincidentally I found the same problem in the 110 only yesterday, just like Widewings video. I was being molested by a seafire and jumped into the gunners seat. Back in the cockpit I found the ASI at zero and a fully developed stall, mushing straight down. Remarkably when I hit the ground the 110 remained intact (more or less) and I got a ditch. The Seafire pilot must have been very frustrated to lose the kill. It had previously happened in the 110 when I got low and slow and ended up at the wrong end of the drag curve. I mushed straight in most frustratingly as I had just murdered three Lancs and wanted to land those kills. What puzzled me was that no combination of engine or control had any effect whatsoever.
It reminded me very much of the 'deep stall' phenomenon, which occurred to aircraft like the Trident or the BAC 1-11 and more recently the Canadair Challenger. However it is a known factor with T-tail aircraft. I don't recall it as an issue with conventionally configured aircraft although the F16 and F18 has been mentioned here.
Having said that, if you think about it. An inverted Spitfire is a de facto T-tail aircraft. The tailplane and elevator might well be blanked by the wing while inverted producing the right conditions for a deep stall.
This doesn't explain similar issues with the Mossie. 110 and P38 which deep stall upright. However all three are twins and two have twin tails. That can't be a coincidence. Another possible consideration is centre of gravity. If it's a little bit aft, perhaps this has an effect. A bit of test flying is perhaps in order.
Just because we have the same result, it doesn't mean we have the same cause.
Of course, given that all of these aircraft are not in fact real. It could be that in fact what we have is an artifact of the programming. HTC are good but they are not NASA. I t could be corrected I suppose but is it really important? When I flew real aircraft I'm careful not to push too close to edge of the envelope (most of the time anyway:O ), because my life depends on it. But in AH, I fly as if I was immortal, which is in fact true. So we do things we certainly would avoid in real life.
It will be interesting to see if the upcoming Combat Tour (two weeks away I hear :rofl) with it's character based play will be different.
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Originally posted by Stoney74
NASA did some testing with spin recovery.
Is this the same NASA that can't figure out how to stop FOAM from bringing down their shuttle??:D
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It happened to me in a 190a5 last night.
got shot up, shut down engine and floated upside down all the way to the ground, about as slow as a chute.
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this stall of death caused me a round in KOTH once:( :lol :rolleyes:
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Originally posted by skycaptn
LEARN TO FLY WITHIN THE LIMITS OF YOUR AIRCRAFT!
and for the love of pete stop :cry ing and :furious ing you whiners.
The problem here is when you fly within the limits of your aircraft and go down anyway. Please take your personal attacks elsewhere.
Thank you.
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Originally posted by OOZ662
The problem here is when you fly within the limits of your aircraft and go down anyway.
If there is a "problem" at all the question is what post-stall characteristics should the spit exhibit? In a stall by definition you've gone beyond the normal limits and departed from flight. That means you've flown outside the limits of the aircraft to get into the situation.
Do departures from flight which are unrecoverable happen in real life? The unequivocal answer is a resounding YES. Do they occur under the situations we've heard described here and seen on a couple of films posted (nose-up zero forward velocity tumbles or tailslides, slow speed inverted departures, etc.)? The answer is again YES. So if they do, it's a credit that we see them even at all in the AH physics model.
Very specifically do inverted deep stalls occur where you end up flat on your back and drop down with no spin in real life? The answer again is yes. Badboy has brought up the F-16 as an example of an aircraft that this occurs in. I'll spare the physics for some other time but essentially pitch equilibrium occurs meaning you can't budge the nose up or down enough or at all to get out of it.
Tango, XO
412th FS Braunco Mustangs
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Well, the point I don't understand is; what happens to the forward thrust from the engine? Yes, you've entered this inverted fall. I could understand how possibly the propeller blades can't properly "bite" the air, but a jet engine?
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Originally posted by hubsonfire
The original question was "is it something that should happen?", and the answer to that is "no, it's not intentional".
I would interpret this to mean that they didn't intend for the spit to do this.
There ya go making sense again hub. That's twice now in a month. What's going on?
Can't you see these guys aren't looking at the actual question? :)
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Originally posted by cpxxx
This doesn't explain similar issues with the Mossie. 110 and P38 which deep stall upright. However all three are twins and two have twin tails. That can't be a coincidence. Another possible consideration is centre of gravity. If it's a little bit aft, perhaps this has an effect. A bit of test flying is perhaps in order.
Would you clarify? I fly the P-38 and I think I've gotten into every situation possible, but I've never done a non-spinning stall that I could not get out of.
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Originally posted by OOZ662
Well, the point I don't understand is; what happens to the forward thrust from the engine? Yes, you've entered this inverted fall. I could understand how possibly the propeller blades can't properly "bite" the air, but a jet engine?
Because thrust isn't a primary factor in determining the angle of attack of the wing (and tail) either in a jet plane or prop. (This isn't true of course for thrust vectoring jet's).
Tango, XO
412th FS Braunco Mustangs
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Originally posted by Guppy35
There ya go making sense again hub. That's twice now in a month. What's going on?
Can't you see these guys aren't looking at the actual question? :)
Pyro's response was carefully worded. The FM of the Spit was NOT coded so that it would INTENTIONALLY have this characteristic. That doesn't mean that the dynamic physics engine modelling the forces acting on the body of the spit outside of normal flight is acting incorrectly resulting in the flat inverted drop.
Tango, XO
412th FS Braunco Mustangs
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Originally posted by dtango
Very specifically do inverted deep stalls occur where you end up flat on your back and drop down with no spin in real life? The answer again is yes.
But missing a wing? I don't buy it that what's happening in-game is a real-life phenomenon.
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Originally posted by BaldEagl
But missing a wing? I don't buy it that what's happening in-game is a real-life phenomenon.
Everything I've mentioned has to do with planes with all their parts :).
How the forces are dynamically acting on a busted up plane is a dynamics problem that aren't typically describable by flight characteristics.
If you don't buy the AH general dynamics then maybe you should draw some free body diagrams to show how the forces should be acting on parts of an airplane falling down.
Tango, XO
412th FS Braunco Mustangs
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I wouldn't include the P-38 in the list. It needs specific conditions in order to enter a flat stall. You need to stall out of the vertical, belly toward the groud with full power and flaps extended. Remove power or flaps and you're no longer pitch locked.
Here is a film example (http://479th.jasminemarie.com/modules.php?op=modload&name=Downloads&file=index&req=getit&lid=39) of an intentional flat stall, an intentional rudder induced spin from the flat stall, and a recovery.
(http://479th.jasminemarie.com/films/spinshot1.jpg)
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Originally posted by dtango
Everything I've mentioned has to do with planes with all their parts :).
How the forces are dynamically acting on a busted up plane is a dynamics problem that aren't typically describable by flight characteristics.
If you don't buy the AH general dynamics then maybe you should draw some free body diagrams to show how the forces should be acting on parts of an airplane falling down.
Tango, XO
412th FS Braunco Mustangs
I'm just saying that the phenomenon described in this thread happened to me in a Spit V with a wing blown off. That leads me to believe that it's a bug rather than accurate modeling.
I have no issues with the AH flight modeling overall which, while I've never flown a real plane much less a WWII fighter, seem incredibly realistic.
Believe me, I'm not dissing you or trying to start an argument, I just don't believe this is a common real-life phenomenon.
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Originally posted by BaldEagl
I'm just saying that the phenomenon described in this thread happened to me in a Spit V with a wing blown off. That leads me to believe that it's a bug rather than accurate modeling.
I have no issues with the AH flight modeling overall which, while I've never flown a real plane much less a WWII fighter, seem incredibly realistic.
Believe me, I'm not dissing you or trying to start an argument, I just don't believe this is a common real-life phenomenon.
I never took your post as a diss :). The inverted "float" down isn't just specific to the Spit minus a wing. That's happened to me in the Mustang as well when I've gotten an entire wing shot off.
If you want something in the real world that might be comparable to this state is that of a falling leaf:
http://www.sas.org/E-Bulletin/2002-11-08/features/body.html
I am saying if folks have a beef about something in the AH physics engine then bring some physics to the table and explain why something isn't realistic.
Tango,XO
412th FS Braunco Mustangs
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"the plane sits still, INVERTED, and floats to the ground. there is no spin, it just sits upside down. no plane falls like a brick upside down, else it would of course be a plane shaped brick, not a combat aircraft..."
I find it admirable that a flight model, as it is now, is able to generate a rather realistic feeling of flying a WW2 era warbird. What I find interesting is that HTC is able to model some of the departure characteristics that various original aircraft had. They probably need to made artificially in the code because otherwise the code should be quite advanced one if it would be able to generate those on aerodynamic data alone and in realtime.
An inverted stall, IMO, is just something the code cannot currently handle and it should be corrected, again, artificially as otherwise it could mean extensive rewrite of FM code.
I have never been in an inverted flat stall without rotation, nor ever seen anybody in one, so I guess it must be rather rare and you need to do everything just right (:-P) to get into one.
That issue is probably on the work list of future FM rework if there is one pending.
-C+
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DEEP STALLS:
Post-stall aerodynamics can be a tricky thing. "At angles of attack beyond stall the airflow about an airplane is extremely complex and the aerodynamic forces and moments become highly nonlinear". Most of us are familiar with the most common post-stall flight mode which is a spin.
There's a less common mode however called the deep stall which also exists, usually occurring at angles of attack well above the critical angle of attack and therefore "deeper" into aerodynamic stall.
The following is a diagram representing these post-stall modes of flight:
(http://brauncomustangs.org/images/post-stall-modes.jpg)
The transition area represents the envelope where an aircraft would typically enter into a spin, while beyond that is the region where deep stall mode of the envelope is encountered. The transition area is characterized by large asymetries in forces in the roll and yaw axis typically initiated by asymetric wing stall. To reach a deep stall, for the test-craft that the data above came from it was necessary to rapidly enter the deep stall region to avoid lingering in the transition area otherwise the aircraft would have entered a spin instead of a deep stall (time required to achieve deep stall was 2 seconds).
CHARACTERISTICS OF A DEEP STALL:
Unlike a spin, an aircraft in a deep stall is extremely stable overpowering the ability of flight controls to reduce angle of attack. The result is often a near vertical descent with nose attitude fairly level with no (or little) spin which is very difficult or impossible to recover from using conventional controls. The following figures illustrate what the result of a deep stall looks like:
(http://brauncomustangs.org/images/fig085.jpg)
(http://brauncomustangs.org/images/deep-stall-fig.jpg)
Infact deep stalls have been tested for the Boeing/UCLA Solar Powered Formation-Flight proto-type as a way to bring the un-manned aircraft down and is described as when "the wing essentially stops flying, and the aircraft descends in an almost parachute-like fashion". (Sound familiar?) There are recorded cases where pilots actually survived unrecoverable deep stalls - one case in point was an amateur built Velocity aircraft where the pilot ended up in a deep stall and tried various ways of attempting to produce a nose pitch down (even with the pilot climbing out of the cockpit and leaning as far forward as possible to try and get the nose down!!!). The pilot considered bailing but elected to stay with the aircraft because of the slow, stable descent and after a hard vertical landing stepped out of the plane uninjured!
Deep stalls have been around for along time and controlled deep stalls have actually been around aviation history since the beginning. The 1902 Wright glider actually had a "parachute" mode that was used as an emergency landing technique. More recently the Kasperwing Ultralight has demonstrated a "vortex mush" flight mode. Already mentioned in the thread are other examples such as the F-16 and T-tailed aircraft that experience deep-stall as well. The British BAC-111 airliner, one of the first t-tail commercial planes suffered a major setback in 1963 when the plane and test crew were lost as they discovered the deep-stall mode of departure for the aircraft. Since then it's been a well documented issue for t-tailed aircraft to design for.
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PHYSICS OF A DEEP STALL:
So what causes an aircraft to end up in a un-recoverable deep stall? It obviously occurs at high angles of attack but is compounded when the horizontal stabilizer (and the elevators) of the tail are no longer effective in changing the angle of attack. Aircraft are designed to have to certain longitudinal (pitch) stability. Lift produced by the wing actually causes a moment force on the aircraft that pitches it up or down due to the center of lift being some distance from the aircraft center of gravity. To oppose this moment force the lift from the horizontal stabilizer of the tail counteracts this force in order to achieve static and dynamic stability. Essentially the lift of the tail creates an opposing pitching moment force to that created by the wing. In aerodynamics the pitching moment co-efficient (usually referred to as Cm) represents this overall pitching moment of a plane.
The following is a diagram that represents the lift, drag, and pitching coefficients of a particular airplane which represents the complex interplay of how the wing and tail and resulting lift and drag impact the overall pitching moment of an airplane at different angles of attack. This figure represents an airplane with rectangular wings and conventional aft tail.
(http://brauncomustangs.org/images/cm-stall1.jpg)
The first interesting range to point out is where lift (Cl) peaks and then drops (stall) and the resulting effect on the pitching moment (Cm). There's a sharp drop in Cm to be more negative which represents an overall force for the nose to go down. The more negative the Cm, the more the pitching moment to force the nose down. The reason this occurs is because the wing itself stalled out produces less left therefore less pitching moment force while the tail continues to produce lift and causes the nose to pitch down more because the wing stalls before the horizontal stabilizer of the tail does (downwash from the main wing induces a lower angle of attack on the tail h-stab therefore postponing the stall of the stabilizer). It's this change in pitching moment as a reaction to stabilize the plane that helps a plane recover from a stall to reduce angle of attack.
The 2nd area to notice is when the tail also stalls at some higher aoa which is represented by when Cm rises meaning less moment force by the tail to pitch the nose down because it's producing less lift due to stall. However in the case above Cm is still negative (nose still wants to pitch down). Eventually drag creates more stability causing the pitching moment to be more negative again. For this aircraft there isn't a deep-stall point where pitching moment is at equilibrium. This means that an aircraft should be able to recover from a deep-stall because a pitching moment exists to be able to reduce the angle of attack and get out of stall.
The following graph however represents a plane that has different post-stall characteristics.
(http://brauncomustangs.org/images/cmstall2.jpg)
The graph looks similar except now notice that there are angles of attack where the pitching moment is either at 0 (equilibrium) or even positive. When the plane has not stalled out this isn't an issue, however where this occurs at higher angles of attack into a stall this becomes very important. It is at these points that the pitching moment is essentially zero which means there's no force available to change the angle of attack of the airplane. From the unstable equlibrium point (25 deg aoa in the aircraft above) with the control held in the same position that would result in recovery in a shallow stall, the plane would quickly rotate to this deep stall trim point. In other words, the deep stall trim point is where the aircraft can no longer produce a pitching moment to change the angle of attack of the airplane and the plane remains at this angle of attack. At this point it becomes difficult if not impossible to recover the aircraft with conventional controls and the airplane literally pancakes into the ground.
For the well documented deep stall t-tail cases, the reason this occurs (where Cm=0 at high aoa) is because the turbulent flow behind the stalled wing actually severely interferes with the airflow for the tail and this wake severely reduces the ability of the tail to stabilize the plane by reducing it's ability to create a corrective pitching moment through tail-lift.
Here's a similar pitching moment vs. aoa chart for the F-16 which shows the regions highlighted where pitching moment is at equilibrium which leads to a deep stall where aoa is in the 50-60 degree range either direction.
(http://brauncomustangs.org/images/16_ExcusesD.jpg)
It should be noted that the deep stall can occur irrespective of the airplane attitude whether it's nose up in the vertical, wings level or wings inverted.
AH DEEP STALL ENTRIES?:
Joe Bill Dryden, a test pilot for the F-16 has write-ups regarding F-16 departure into deep stall including inverted deep stalls. The situations leading to deep stall usually occur when the airspeed of the aircraft was at zero in ther vertical or at slow speed with a hard maneuver. In either case the computerized flight control system isn't able to correct quickly enough for the rapidly changing aoa.
I theorize this is basically what is happening in the AH flight model. As Widewing's film of the Mosquito demonstrates as the mossie nears 0 airspeed with nose pointed up the nose begins to drop. This resultant drop whether pitched back or pitched forward represents rapidly changing angle of attack because the free-stream air is striking the leading edge of the wing at angles of attack that increase very rapidly due to the motion of the rotation with the nose coming down.
(http://brauncomustangs.org/images/ahfm-deep-stall.jpg)
Very quickly we find that both the wing (and tail) are at high angles of attack passing through the transition zone where a spin occurs and into aoa well in excess of the critical aoa. In this attitude the tail (and elevator) is essentially unable to produce enough lift to create a negative pitching moment to offset whatever lift is produced by the wing inorder to pitch the nose down. Essentially the aircraft is now in state that pitch equilibrium has been reached (like our graph above where Cm=0 at high aoa) and we pancake into the ground either upright or inverted.
I have not seen any film or have I tried reproducing the inverted deep stall of the Spitfire I. I'm guessing essentially something similar is happening where the aircraft is at or near zero airspeed and begins to fall which results again in a very high aoa attitude very quickly passing through the spin zone and into a deep stall.
Whether deep stall trim points exist for each of the AH airplanes in real life is another question. Post-stall dynamics as mentioned are very tricky to estimate and model. The question is does enough pitching moment exists at very high angles of attack post-stall to pitch the nose in order to reduce aoa depending on the configuration and design of the aircraft. But from what I can tell it appears the unrecoverable float downs we are seeing in AH is essentially a deep stall.
Sources:
(1) Mechanics of Flight, Warren Phillips. 2004.
(2) NASA TN86401: Flight Characteristics of a Manned, Lowspeed, Controlled Deep Stall Vehicle, Alex G. Sim. Aug 1984.
(3) Explaning Aerodynamic Stall, Mark McCabe, Aviation Litigation Monthly, Fall 2002.
(4) Formation Flight Model Tested, NASA Dryden Flight Research Center, Aug 1997.
(5) No Excuses, Joe Bill Dryden. Code One Magazine, July 1991.
(6) Concept to Reality: Contributions of NASA Langley Research Center to US Civil Aircraft of the 1990s, Joseph R. Chambers, Oct 2003.
Tango, XO
412th FS Braunco Mustangs
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try looping a fully fuled 51 and get below 100 ias on top, youll know you made a mistake, 38 has a nasty habit of barrrel rolling to death when heavy, corsairs snap stall and ground loop, mossies spin hard because of torque with flaps out, ki84's, and 190's snap out of turns when pulled to hard, 109's lawn dart, and ground loop under breaking, and finaly spits fall out of the sky inverted when roll and back pressure on the stick are to much.....military a/c in worldwar 2 pushed the ragged edge of tech...so the planes may be touchy, this is why the game doesnt suck {accept for main arena being nueterd}:aok
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Originally posted by dtango
PHYSICS OF A DEEP STALL:
I have not seen any film or have I tried reproducing the inverted deep stall of the Spitfire I. I'm guessing essentially something similar is happening where the aircraft is at or near zero airspeed and begins to fall which results again in a very high aoa attitude very quickly passing through the spin zone and into a deep stall.
Tango, XO
412th FS Braunco Mustangs
Here's a film of a SpitV worked into an inverted stall.
It seems to me that P factor is not modeled. Prop wash impingment on the rudder ought to induce some rotation. I can see how a glider might drop vertically, but torque and P factor should have some effect, I would think.
Spit Mk.V inverted stall (http://home.att.net/~c.c.jordan/SpitV-Stall.ahf)
My regards,
Widewing
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Widewing- thanks for the film. I had a chance to briefly look at it before I went into work. Will study it a bit further this evening. Initially it appears very similar to the graphic I had above except the plane is inverted so I think it's the same entry as I described.
Regarding corkscrewing propwash, it's conceivable that because the plane is falling the impact of propwash on yaw is limited because the high angle of the freestream direction of airflow relative to propwash due to a vertical drop is dissipating the effect of propwash.
EDIT: 2ndly regarding p-factor, I'm not sure how this might effect yaw in a vertical inverted drop since p-factor is a result of difference in speeds of the upgoing and downgoing blades when tilted at some angle with respect to oncoming airflow.
Thirdly this may also be accounting for offsetting any torque effects in the roll axis because the plane is falling flat and again the relative angle of freestream airflow is impinging on the wings and h-stab creating moment forces that torque doesn't overcome.
Tango, XO
412th FS Braunco Mustangs