Aces High Bulletin Board
Help and Support Forums => Help and Training => Topic started by: Benny Moore on January 29, 2007, 11:01:51 PM
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I've always flown the P-38, so I've never had a problem doing an aerobatic hammerhead. However, recently I've been expanding into the other two of the Big Three, and haven't been able to perform it nearly as consistently. Now one of the regulars in my server has suggested that the stall modelling is bogus and that his Me-109 cannot hammerhead. I immediately began defending the stall modelling, as it's by far the best I've seen in any aerial combat simulator. However, upon actually trying to hammerhead the 109 I came to the conclusion that he is at least partially right; the Me-109 can't do a hammerhead. I tried power off, I tried power on; I tried light, I tried heavy; I tried going with the propeller, I tried going against the propeller. I'm stumped.
Can anyone do a true hammerhead in an Me-109? If so, can you post a film with instructions? And if it can't, is it intentional modelling based on the real Me-109's stalling characteristics or is it a bug?
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Benny if you are able to do a true hammerhead in AH I'd like to see a film of it. I've never been able to do one in any plane in AH.
Even HT has trouble flying the vertical line in AH.
Are you sure you're not doing what amounts to a more vertical wing over?
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http://users.adelphia.net/~j.r.engdahl/josh/P-38%20Hammerhead.ahf
It's not perfect, but I do think it counts as a proper hammerhead. I think I can also occasionally do this in the P-47 and P-51, but nowhere nearly as neatly or consistently. However, I simply cannot do it in the Me-109.
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Sorry to say, that's a more vertical wingover with a stall at the top. :)
A hammerhead is straight vertical with rotation on the yaw axis and straight back down. The yaw rotation is done with full rudder and opposite aileron and stopped with opposite rudder.
Trust me it's not you or the coding, without the sensation from the seat of your pants and a good reference point you'll always roll over the top (as you do in the film) resulting in a high wingover or come up short with a true wingover when trying to do a hammerhead in AH.
The only way I can see a true hammerhead being done in AH is 1..pure luck or 2..If HT adds a vertical bubble guage on one side of the plane.
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I agree that a pure, aerobatic hammerhead is tough to do with the 109 but you can't blame stall as the wing never stalls in this maneuver. Stall occurs when you reach critical AOA and in a true hammerhead you are looking for zero lift on the wing so have 0 or slightly negative AOA.
As you decelerate in the vertical you actually have to feed in quite a bit of forward stick to keep from arcing over onto your back and stay pure vertical. As you start the hammerhead with full rudder (lets say left) the stick needs to go forward and to the right. Forward to maintain vertical and to the right to counter torque and dihedral affects. Since you're pivoting the plane around the yaw axis as NHawk describes the right wing is moving faster than the left and will generate a slight amount of lift causing more of a wingover if you don't counter it with right stick.
The ability to do an aerobatic hammerhead depends quite a bit on your rudder power, i.e., it needs to be effective enough to generate enough yaw at slow speeds. Torque and dihedral are also significant issues. I have no idea if a real 109 has the ability to do a pure hammerhead.
Mace
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I used to fly RC aerobatic competition and the hammerhead was sort of my signature maneuver. Obviously there is a bit of difference between an Extra 300 and a 109. :D However, here is how I do a hammer in an Extra 300:
From level flight pull straight up into a vertical and go full throttle. About half way up the vertical line I pull back to idle and let the plane coast the rest of the way up the line using very slight aileron and elevator inputs to keep things perfectly straight. Now the tricky part: just as the plane comes to a complete stop in the vertical (stalls), goose the throttle (full up and back down) and simultaneously kick in full rudder while making very fine corrections with aileron and elevator. If timed just right, the tail will slide around so that the nose is pointed back down the direction it came while continuing to remain perfectly on the vertical line. Ease back up on the throttle a bit on the down line just to keep it from wobbling too much. The tail will give a little "wag" on the down line. Judges love to see that little wag as proof that your plane actually stalled as the hammerhead is a true stall maneuver opposed to a wingover where there is no stall.
Hope that adds a little to the discussion.
BTW, I've never had any real luck doing this in Aces High in any plane.
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I'm fairly certain that I didn't roll in that clip. Watch it from "fixed" view. I rotate purely on my yaw axis (barring a few degrees of roll, as I said it's not a perfect hammerhead). I'm still not sure what a wing-over is, as I've heard many conflicting descriptions. But I do know what a hammerhead is, and I think I got in the P-38.
So, why is it that we can't do hammerheads (not counting the P-38, assuming that it was a hammerhead I did)? Is it just that hammerheads are very hard to do in reality and since we don't have the feel, it's almost impossible to do them in the game? Or is it that warbirds were a lot crankier in the hammerhead than modern aircraft? Or is it a problem with the modelling?
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The easy way to describe a hammerhead vs a wingover is this.
Take a piece of paper and draw an arrow on it. Hold the arrow pointing up. Rotate the paper so the arrow is pointing down. That's a hammerhead.
Now a basic wingover is like this.. Hold the arrow pointing up, as you turn it slowly to the down position move the paper either left or right of it's original vertical position coming horizontal off of the turn.
I don't know any better way to describe it.
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Speaking scrictly from an areobatic competition stand point (a wingover is not a competition maneuver BTW), a wingover is a hammerhead that doesn't stall. Judges would often write "WO" (wingover) on your scorecard beside the hammerhead maneuver to indicate that you made your down turn too soon and there was no stall at the top. Hammerheads are pretty much areobatic tricks and (as far as I know) have no usefullness in ACM.
A hammerhead is among a number of aerobatic maneuvers called 3D maneuvers which exploit stalls and prop torque allowing you to perform tricks such as flat spins, tumbles and torque rolls. I never really got real good at this stuff but I could do basic flat spins, torque rolls and short prop hovers. Out of all the flight sim games I've played (FS, AH, IL2), I can't do any of this stuff. I think the physics is just beyond the ability to simulate. The hammerhead is one in which I would score close to 100 in every competition I ever flew (I can do that one very well) and I can't come even close to doing one in any of these flight games. I just don't think the simulation can recreate the 3D effects well enough.
Just my opinion of course. Maybe some of you guys can do this stuff. My hat's off to you if so. I feel pretty confident though that if you can do some of these then you are "gaming the game" rather than doing them as the REALLY are done. I remember when I first got FS2004. One of the very first things I did was take Patty Waggstaff's Extra 300 up for some hammerheads. I was big time disappointed that I was unable to even come close to doing one. I'm sure there is a "gamming trick" to doing it but I lost interest real quick as I realized that the physics just wasn't there.
I think the appropriate phrase may be "a game's gotta know its limitations." As for me, I can live with that.
-hb
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Forgive my ignorance here, But when would a hammerhead be good in AH? Is it more of a Aerobatic manouver? It looks like you go straight up till you stall then fall back down again? A rope manouver perhaps?
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With trails on it is obvious that Benny's clip isnt a hammerhead. If it were there would be no seperation in the up and down trails.
But the larger question is why you want to do a hammerhead?
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Originally posted by Gumbeau But the larger question is why you want to do a hammerhead? [/B]
Because it's fun?
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I wanted to do a hammerhead because someone complained that the vertical stall modelling was unrealistic, and I was trying to prove him wrong. That, and it's fun.
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About the only real reason you might use one would be in a very competitive rope where the other guy has just slightly less e so you have to stretch your vertical move as far as possible. In reality you're just doing a rudder reversal and some roll during the maneuver will pretty much give you the same result and it's easier.
Regarding the modeling I'm not really sure. I don't know for a fact that WWII fighters were really capable of a true aerobatic hammerhead but I do know that you don't seem to get the "kick" from the blast of power right at the top so you don't really seem to be able to generate a lot of yaw rate which is what you need. Regarding the "stall" the hammerhead isn't a stall, it's a ballistic maneuver. The airplane is too slow for aerodynamic control to have much effect, hence the blast of power to kick the tail around. The reason it isn't technically a true stall is because when you're going pure vertical you're not getting (nor do you want) any lift from the wing at all so no lift, no AOA, no stall.
As far as other aerobatic maneuvers in AH, it's also very hard but not impossible to get a true tail slide; however, I've tried numerous times to do a Lomcevak and have never successfully done it. In another thread I've asked about both the prop wash for rudder reversals and whether or not moments are modeled around all three axis which is what's required, along with control power, for the Lomcevak.
Mace
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Hammerhead (http://www.fightercombat.com/clips/hammerhead_high.wmv)
Never can do it in AH2 as i did in WB time ago.
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Unholy flip turn, p38 still does it the best though.
Secret is to keep it straight up till airspeed drops to 0, then full Rudder kick and down the other way.
Is it easy in a 109, heck no, doable, I'd say so.
As to why, if your higher, faster than the guy behind you, and you pull up into a hammerhead, and if you've judged the E states correctly. He will try to follow you up, stall, & flop, at about the same time that you do the hammer head, flip, and have him 400 below you, in your sights, full plan form shot. Ping Ping Ping BANG no more bogey.
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Originally posted by Ghosth
Secret is to keep it straight up till airspeed drops to 0, then full Rudder kick and down the other way.
Dont work for me. I used hammerhead often while flew in WB and know how to do it. But in AH plane dont flip, it fall tail down and spin eventually. I dont check every plane though.
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Originally posted by Benny Moore
I wanted to do a hammerhead because someone complained that the vertical stall modelling was unrealistic, and I was trying to prove him wrong. That, and it's fun.
Thats an excellent reason :)
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Ghosth, can you post a film with hammerhead (in any plane except p-38) please?
I tried it today once more and still cannt do correct. Best i can do is wingover that close enough to hammerhead, but not hammerhead yet.
Ever in p-38 hammerhead is quite slow and hard to do.
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Oleg, I will try to take this project on in the TA when I have time.
Starting with the RV8 is I suppose cheating eh?
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Originally posted by Ghosth
Starting with the RV8 is I suppose cheating eh?
Sure :lol Better take something with guns :)
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Well it appears your right oleg. According to Widewing, there is no P factor modeled, so the rudder doesn't bite as it falls. Thus forceing the plane to fall off to top or bottom instead of side.
Val comes closest, but even it likes to roll half turn before heading back down
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Originally posted by Ghosth
... According to Widewing, there is no P factor modeled, ...
Ah! I knew it! I'm so smart. :)
I'm telling you, I know how to do this in a real airplane and AH (or any sim I've ever tried) just doesn't have the "feel." It is definitely a modeling issue.
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Originally posted by Ghosth
Well it appears your right oleg. According to Widewing, there is no P factor modeled, so the rudder doesn't bite as it falls. Thus forceing the plane to fall off to top or bottom instead of side.
Thanks for trying.
Hammerhead is very nice and effective maneuver, sadly it impossible here.
By the way, looks like Benny going to loose :lol
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Originally posted by Ghosth
According to Widewing, there is no P factor modeled, so the rudder doesn't bite as it falls. Thus forceing the plane to fall off to top or bottom instead of side.
And according to Hitech:
Sigh, some days I feel like we should have a section on physics 101.
Roll Torque on the plane is very easy to calculate it's simply current HP / prop rpm.
What most people refer to torque, the stuff on take off that makes your plane yaw,has nothing to do with Roll Torque, it has every thing to do with the slip stream/prop wash.
The 2 other forces that produce yaw do to the prop/eng they are gyroscopic (this only produces yaw if you are changing pitch) i.e. when your tail lifts. The final force is PFactor, it only has much effect at high speeds and hi aoa's.
AH Models all 4 prop forces, 3 of which I'm confidant we are with 5% of the real plane.
I'm not happy with our slip stream effects, we have been doing more research into calculating the slip stream, and it will change in some later version.
HiTech
That quote is from 2001 btw.
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Though I've already stated that I think all these prop sim games miss the mark with respect to 3D maneuvers, I do think AH has the best modeling of the three I have the most experience with. IL2+++ comes in next but I believe over does the effects to the point that the planes are way more difficult to control than I think they really should be. The worst of the three by far is MS FS2004 (haven't tried X) which is disappointing since that game is all about just flying. The third party pay planes improve the flight modeling some what but FS is horrible (IMO) in this department. I never tried Xplane but I've heard people say that the flight model is not too bad. I used to play Fly! years ago and that wasn't half bad; certainly better than FS.
I have long ago accepted the fact that these are just games and the developers are forced to choose what they think is important to model and have to let the rest go. If you want to experience REAL flight then you will have to REALLY fly!
..grain of salt
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I've mentioned this before but does anyone have any proof that WWII airplanes were capable of true hammerheads?
Aerobatic airplanes are considerably different from combat planes. They usually have symetrical airfoils, very high thrust to weight ratios and exceptional control power. Besides this, they tend to be relatively less stable aircraft requiring quite a lot of pilot control. Fighters have many of these same attributes but to lesser degrees. They have non-symetrical airfoils, high thrust to weight ratios but less than a pure aerobatic plane since they have to drag around a bunch of junk (guns and armor for instance), and while they typically have good control power the controls have to be a good balance between maneuverability and stability. Same for basic airframe stability. Aerobatic planes don't have to land on aircraft carriers, don't have to deal with wide CG ranges and don't have to be able to maintain a guns tracking solution.
I'm not saying combat aircraft can't (or shouldn't be able to) do hammerheads, I just don't know for a fact they can so we shouldn't get too wound up about this unless someone can prove they could and, if so, which ones.
Mace
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Originally posted by HomeBoy
I do think AH has the best modeling of the three I have the most experience with. IL2+++ comes in next but I believe over does the effects to the point that the planes are way more difficult to control than I think they really should be.
I never tried Xplane but I've heard people say that the flight model is not too bad.
The IL-2 series is a joke. It does not have a dynamic stall model as Aces High II does. In IL-2, either you're flying or you're spinning. There's no in between, and you cannot stall any airplane without dropping a wing (except for the airplanes with slats, because somehow slats magically prevent that). Since we have United States Army Air Force training videos still easily available today, we can know how various warplanes should stall. For example, the P-51B should have a wing drop tendency even with power off, but the P-47 should not, and the P-38 should have no wing drop tendency in any stall unless the gear is down or external stores are loaded, disrupting the airflow. But IL-2 doesn't figure any of that stuff, according to them all airplanes drop a wing when they stall and, if held in the stall, will always spin.
Actually, I must make a slight retraction; after having enough data shoved down their throat (about half a dozen good sources) they finally changed in one of the later patches the P-38's power off stall. This kept it from dropping a wing. How did they do this? They simply lowered the effectiveness of the elevator with power off so that the airplane is unable to pull a high enough angle of attack to actually stall. The stall model is still drastically wrong (as proved by the P-38's power on stall, which still results in a spin every time).
The folks over at Maddox don't feel that stalls are important. The player base largely agrees, judging from the heated attacks on me when I pointed out the problems with the stall model. Proof via videos certainly didn't help, nor did the opinions of me and many others who have stalled real airplanes. IL-2 is a joke through and through, and the stalls are only the largest problem. I wasn't very impressed with X-Plane, either, although that was certainly better than IL-2. Really, Aces High is by far the closest thing I've seen, judging by my real stick time and from the videos we have of World War Two fighters stalling.