Helicopters turning point what model moves when flying helicopter is too low. It is positioned middle of the all models causing wrong feeling to flying and and makes vehicle look "skating in air" when helicopter rolls around middle of fuselag.
The point should be in ARMA 3 at the rotor axis or even little above it
{F21279} {F21280} {F21281}
Video comparision of helicopter simulator (DCS:Black Shark), old arcade action game (Gunship!) and ARMA 3:
http://www.youtube.com/watch?v=J3LJ5R-Zi3U
Video comparision of helicopter simulator (DCS: UH-1H Huey and ARMA 3):
http://youtu.be/bC1MgXnqMnI
Mockup is from Mi-48 helicopter but same thing is with all helicopters, the point is too low.
Why?
When torque from the rotor is applied, the helicopter is rotated around the center of mass, not some artificial point "below the rotors". That's base physics.
And the center of mass certainly can't be so high, the current position is actually a pretty good representation.
In some few cases helicopter rotates by its center position, but in most cases when moving it does not but more below the rotors. Basic physics with gravity, air resistance and dragging point with mass.
The current rotation point being middle of the model only works when helicopter moves from hover position to any direction (yawn, pitch or roll) but when it is moving, it is unrealistic in many situations and mostly the point being little up would be better.
If you play DCS: Black Shark, DCS: Huey or X-Plane 10 you can see that helicopters physics is not that you rotate around middle point like in ARMA 3 but above it and below rotor when you are moving.
Nope, it's just the camera in these games may be fixed slightly higher w.r.t. the chopper frame, than in ArmA 3 :) The helicopter still rotates around enter of mass.
ARMA 2/3 use fixed camera point to middle where the helicopter turns.
All simulators gives you free movement but allows you to as well have a fixed camera point.
In simulators helicopters DOES NOT rotate around the center of mass than in very rare cases (like you are in perfect hover and from there you roll or pitch) but once you are flying the mass isn't the center point.
If you would have played those simulators, you would know that helicopters don't rotate around center airframe like in ARMA. When you fly or you do small collective changes in hover, you swing below rotor position.
Your opinion is other if you want to claim that ARMA has better physics for helicopters than those simulators I mentioned ;)
My "opinion" is based on physics knowledge and experience in working on aerodynamics in Rise of Flight project (http://riseofflight.com/en). This experience tells me physics better describe what's actually happening with an aircraft than a layman's senses. Clear?
If you could prove that it is unrealistic, that'd be great. I'm not doubting you or anything, but surely the developers will need to be convinced before changing anything.
Uh-huh. If you're saying sun is not a teapot - prove it.
What you're requesting here is against the basic physics (okay, not basic... http://en.wikipedia.org/wiki/Theoretical_Mechanics, actually). You should prove it, not me.
Hint: the torque (rotational force) is always applied relative to the center of mass.
So you compare your experience of fixed wings to rotating aircraft and you believe they have same physics and even between WW2 era and helicopter? Only at some situations and rare cases it is so but I will get videos for you when I get home and have time. As once you fly helicopters, you do notice their flight model is totally different and you can not just jump between them and believe exactly same rules applies.
I do believe you do have at least basic knowledge of huge differences between fixed wings being below or top of fuselage and how they do reflect flight model.
And if you really argue that rotation is always middle of the mass, then you don't know anything about flight modeling as it isnt basic physics without drag, torgue and dozens of other physic laws. And developers knows it, they modeled same way as I suggest their helicopter game, so why not now on arma3?
All you really need to prove is that "When torque from the rotor is applied, the helicopter is rotated around the center of mass". Most of us would have no idea if this was true or not, and if it is, then it supports your cause.
Not sure if I'm correct here.
Look at this video http://youtu.be/o6UxS4dAZfs?t=32s
Notice how the pilot has to fight gravity for the first part of the roll and how gravity helps him in the second part.
If the center of rotation was the center of mass he wouldn't have to fight gravity, only inertia. Right?
Yeah the centre of gravity/turning point should be higher, at the moment it feels like flying a fixed wing aircraft, which is what darkwanderer is talking about, the centre of mass might be lower on the ground but lift in the blades brings it higher.
OMG...
I hope noone here will argue that physics is wrong? I truly hope so.
In mechanics, when you have a body, you have following parameters:
Both force and torque vectors are always applied to center of mass. The only exception is when the body is fixed with less than 6 degrees of freedom (i.e. on a hinge). With helicopters - this is not the case. They have full 6 DOF of motion.
Hence, when you have torque applied, in the reference frame fixed to the helicopter, it will always rotate around center of mass. Period. No other options possible. That's the basics of physics.
When the helicopter is moving, it may appear to a stationary observer that the body of the helicopter is rotating around some other point. For example, when performing funnel maneuver, the body of the helicopter will seem rotating around a vertical axis starting at the funnel focus. However, if we look from the helicopter's point of reference, the rotation will always be around CoM. Period. End of story. What you see is NOT what you get, unlike Microsoft Word.
And - surprise, surprise - aerodynamical forces and torques are just parts of the "total force" and "total torque" vectors. It may look as if it works otherwise - but it is not. It's all the same equations -
F = M*(dv/dt) (Second Newton's law, I hope you know at least as little as that)
T = I*(dL/dt) (torque equals inertia tensor multiplied by angular acceleration)
All the aerodynamical calculations are applied on top of that - to get the forces and torques. They are complex and different, yes. But when the aerodynamic stuff is done, Mr Newton takes the wheel - and all goes according to his laws.
Hence, Mr. Fri13, yes, I compare my physics background and experience in aerodynamic modelling to your ostensibly hardly finished high school physics. Surprise again - all macroscopic bodies comply to the same newtonian physics, be they helicopters, planes, or anything else. ISS motion is described by the same equations that apply to a bowling ball, WWI fighter, WWII fighter, modern fighter, ballistic physics, basketball, volleyball, gyroscopes, mechanical clock, lawnmovers, parachutists, skateboards and policemen.
And for the reference: yes, I've played DCS: Black Shark, Lock On series, Falcon 4 (plain and AF) and Orbiter space sim. I've also developed a couple of addons for Orbiter. In RoF, I've worked on physics of the Fokker triplane - there, we had some problems with actually making the thing fly like IRL - because NACA wing profile data does not give any information regarding the interactions of three closely-placed wings.
In all of these simulators, the model I've described is in the base of everything (except some scripted spins in Falcon 4 and Lock On). You can ask developers of any of those sims - or you can ask BIS developers. They've done good job with the TKOH flight model. Obviously, the answer that it's the same good ol' physics will surprise you.
Don't tell me *I* don't know physics.
EDIT: Damn it, I've fell to a manipulative troll. Shame on me.
Good job, Mr. Fri13. I hope your pimpled personality feels much better now.
Then you must be so great as tools what world biggest airplane manufacturers use to model their planes, shows that the rotating axis is not middle of the helicopter body as you think, but above it below rotors.
I can not argue with you what you can even feel and see when you are in flying helicopter as it is against what you say.
I am back flying helicopter on next week and I must just be in other world as I can even feel instead just see that the middle of fuselag is not the turning axis as you claim.
You say you have played DCS:BS(2) but still you can not even in it see that what you say, is against it. In ARMA helicopters fly as you say, but on simulators and reality helicopters don't fly in that manner. Which one you want now to defend, ARMA or simulators and reality? As both can not be correct.
To add here, I am aware of laws of physics so you have nothing to add here.
But you fail here to apply those laws of physics to helicopter as you believe rotating wings behave exactly with same manner as fixed aircraft.
Different design, different flight model.
You claim that helicopter fuselag generates torque and thats why whole aircraft rotates around center of mass => Center of fuselag.
Tell what is wrong in this: http://i.imgur.com/NKF2TfA.png (just imagine helicopter is not co-axial)
ps. When you call someone manipulative troll, be careful as some people would find it very offensive. As you are one doing personal attacks like very experienced person on that area.
Don't argue with Fri13, he is an experienced czech ex-sniper helicopter designer.
Better use official knowledge:
There is NOTHING what I don't already know in the URL you added. Do you want to express your hurting feelings more?
Maybe you like to express your knowledge of helicopter flight dynamics and how they are perfect in ARMA III?
Funny. Who said helicopters were perfect? But as you already know, ArmA 3 is not a simulation because you don't want the game to be one.
And on a side note: I really like trolls. You are my favourite. No hurt feelings. You never fail to amuse me.
Aww.... Still you try to offend me by saying I don't want ARMA 3 to be a simulator, failing in it because I have told it is not a simulator, not that I would not want it to be a little more realistic in gameplay manner. And instead you would try to make arguments, you do Ad Hominem.
Just like in this ticket again, instead to make helicopters in ARMA III little better, you just want to do personal attacks.
Because you have nothing else to add this ticket, what if you would do as you promised to do yourself and not to react anything what I write?
Please stay on topic here. That's the reason that this feedback tracker exists. Not to argue back and forth.
Fri13, I'm not knowledgable enough in this area to know if what you are claiming is accurate, but the way you need to present this kind of claim is with evidence, resources and a sound argument. Saying what you have and supplying a couple of pictures conveys the idea of what you're after quite well, but it doesn't explain whether it's accurate or, approaching from another angle, whether it's a greater benefit to gameplay. Doing this and/or countering the claims put up as opposition to you would work better.
Rotation axis should be near the Swashplate just below the main rotor.
http://www.youtube.com/watch?v=RGu45s1_QPU
The helicopter body essentially 'hangs' from the rotor.
Then you must be so great as tools what world biggest airplane manufacturers use to model their planes, shows that the rotating axis is not middle of the helicopter body as you think, but above it below rotors.
Which tools? Screenshot, proof? Otherwise it's just talks.
I can not argue with you what you can even feel and see when you are in flying helicopter as it is against what you say.
"I feel it should be that way" is a great argument, no doubt. Unfortunately, feelings do change nothing here, it's pure physics.
I am back flying helicopter on next week and I must just be in other world as I can even feel instead just see that the middle of fuselag is not the turning axis as you claim.
Again, what you feel is not what you get.
You say you have played DCS:BS(2) but still you can not even in it see that what you say, is against it. In ARMA helicopters fly as you say, but on simulators and reality helicopters don't fly in that manner. Which one you want now to defend, ARMA or simulators and reality? As both can not be correct.
I don't defend any simulator. I'm saying you've got wrong assumptions. And in both simulators and in reality helicopter fly like they should - adhering to the physics I've described.
To add here, I am aware of laws of physics so you have nothing to add here.
But you fail here to apply those laws of physics to helicopter as you believe rotating wings behave exactly with same manner as fixed aircraft.
Nope, it's you who fails here. Because newtonian physics apply to any macroscopic body. It's not even aerodynamics, it's basic physics you fail at.
Different design, different flight model.
Different flight model, yes. Non-newtonian physics, no.
You claim that helicopter fuselag generates torque and thats why whole aircraft rotates around center of mass => Center of fuselag.
That's what you're saying, not me.
Tell what is wrong in this: http://i.imgur.com/NKF2TfA.png [^] (just imagine helicopter is not co-axial)
Do you think this picture proves me wrong? Nope.
ps. When you call someone manipulative troll, be careful as some people would find it very offensive. As you are one doing personal attacks like very experienced person on that area.
First of all, the first personal attack was yours. You claimed that I have no knowledge in the area.
Second, you are ascribing many wrong points to me - the ones which I never stated. This is pure and plain manipulation.
Third, yes, I do have quite good experience in modelling of mechanical processes and software development.
@Darkwandered
"Which tools? Screenshot, proof? Otherwise it's just talks."
Example X-Plane 10 (Oh, you didn't know manufacturers use it too to design and test aircrafts and that flight schools use it in teachings as well?)
Oh and it is childish to yell "Screenshots or nothing happened"
http://i.imgur.com/Yj3xeHH.png
""I feel it should be that way" is a great argument, no doubt. Unfortunately, feelings do change nothing here, it's pure physics."
You claim that helicopter always rotates around Z axis because torque. Can you please explain how the torque from Y axis is transmitted to Z axis? Pure physics states helicopter is a big pendulum and middle of helicopter fuselag is not the point what stay still and everything turns around it.
And sorry, feeling directly tells you how helicopter behaves in different situations if you ever have flied helicopter in your life (or you have any senses), not the physics book. There is difference knowing the path than walking the path, if you get the drift.
"I don't defend any simulator. I'm saying you've got wrong assumptions. And in both simulators and in reality helicopter fly like they should - adhering to the physics I've described."
In reality and in simulators helicopters torque is not in Z axis as you claim or it does not rotate around middle of fuselag in most cases but like I presented in the mockup the Z axis being too low and should be above.
In real life helicopters don't roll around fuselag as you try to proof that ARMA III does it very well.
"Nope, it's you who fails here. Because newtonian physics apply to any macroscopic body. It's not even aerodynamics, it's basic physics you fail at."
I already told that laws of physics are not the problem, you are just applying them as helicopter would be fixed wing from WW2 era.
"Different flight model, yes. Non-newtonian physics, no."
Good you have understood that :)
Now you need to learn to apply the laws of physics differently and understand that helicopters don't fly like fixed wings and that fuselag does not generate torque in Z axis.
"Do you think this picture proves me wrong? Nope."
Well answered, you even failed to see there is a problem but instead you would have pointed it out, you didn't seem to even see it. And even with that problem, it does point you wrong.
"First of all, the first personal attack was yours. You claimed that I have no knowledge in the area."
First of all I said (and I quote):
"I do believe you do have at least basic knowledge of huge differences between fixed wings being below or top of fuselage and how they do reflect flight model.
And if you really argue that rotation is always middle of the mass, then you don't know anything about flight modeling"
No read it again. I say that I believe you have at least (at LEAST) basic knowledge of area with an example. I am not denying it as you claim.
But then I said that IF you really argue that torque is generated by Z axis and helicopters always rotate middle of the mass, then you don't know anything about flight modeling.
As you claim (and I quote)
"When torque from the rotor is applied, the helicopter is rotated around the center of mass, not some artificial point "below the rotors". That's base physics.
And the center of mass certainly can't be so high, the current position is actually a pretty good representation."
You need to proof that torque is applied to middle of the fuselag, what you can not because fuselag does not generate any torque at Z axis as you claim.
The torque is applied to Y axis middle of the rotor pole is, it is not on Z axis and it is not middle of the fuselag. Torque from rotor causes fuselag to change its yaw and thats why helicopters have anti-torque rotor (aka tail rotor) to allow pilot to keep heading by adjusting anti-torque rotor pitch correctly with anti-torque pedals.
You did not even understand how gravitational force with countering lift force from rotational motion where is bernoulli's principle applied in such way to generate as strong lift trough whole blade (to some point like until descent rate exceeds the airspeed or downwash).
With few basic helicopter flight models you have failed to understand that helicopter does not rotate around the middle of fuselag point what you insist continually and claim it generates torque as torque is on Y axis http://i.imgur.com/fyQf1lF.jpg
I did not start personal attacks, I only said that if you claim something against laws of physics, then you don't know anything about flight modeling. You have made claims what are against laws of physics and you started personal attacks (what you could have left out) because you were incapable to even proof that helicopter fuselag rotates around Z axis because it generates the torque.
You sir made claim that "sun rotates around earth" and you got mad because other person pointed that "earth rotates around sun".
Edit: I reviewed TOH as it has been a while I tested it and I correct myself that it has very flawed helicopter flight modeling. Over half of the most common modelings don't exist in it as they do in other simulators.
@Longjocks
"Fri13, I'm not knowledgable enough in this area to know if what you are claiming is accurate, but the way you need to present this kind of claim is with evidence, resources and a sound argument. Saying what you have and supplying a couple of pictures conveys the idea of what you're after quite well, but it doesn't explain whether it's accurate or, approaching from another angle, whether it's a greater benefit to gameplay."
The picture was for developers because they know their modeling is wrong, not for community. I need to upload video somehow (or ask someone to upload it as I don't have accounts any such services) to present it to community.
And for gameplay it makes it harder to fly and transmit better "feeling" (as what you can now in games get) how helicopters should behave in ARMA 3 even with its very simple flight modeling. There have been arcade games trying to give the correct experience in less features than what ARMA 3 supports and they have succeeded to transmit msot common flight models to kids. Flying in ARMA 3 with helicopter is still like trying to fly a broom and believe it is a helicopter weighting few tons.
It is not about requesting full/complex flight modeling for each helicopter but simply to get the basics correct what eventually helps most chair pilots to do more sensitive adjustments. As far I know the flight modeling in ARMA 3 is shared between all aircrafts and thats why helicopters act like fixed wings but if there is possibility to even get the small thing (rotational point) changed from middle of the model to above (top) swashplate it would help a lot in basics.
Edit: Friend uploaded file behalf of me so all who thinks ARMA 3 flight modeling is realistic and against that the axis point would be transferred up can see more clearly how simulators and even arcade action game model helicopter rotation.
ARMA3 axis is TOO LOW.
Don't bother talking about physics if its not related DIRECTLY to rotary aircraft.
LOOK AT REALITY
http://www.youtube.com/watch?v=n9ZUXNeBoHo
http://www.youtube.com/watch?v=uYbx5H5e9Es
The ROLL axis is roughly through the pilots head.
If you just wanted to vote idea up just change your vote to support it, no need to link more videos how the rotation axis is above the ones what is in game. :)
Can someone down voters explain why AH-9 should fly like it is on ball and the turn axis is even little bit below the fuselag bottom?
Even you DarkWanderer should see something wrong in its modeling?
I guess you don't take scientific evidence seriously. The pictures in the OP show a rotation point WAY over the center of gravity. And it is only ONE helicopter. Not every object has it's center mass in the same location. Since I am not an aviator, I don't compare the reality to the in-game flight model, just correcting wrong physical assumptions.
The center of gravity varies between aircraft models. For some it is higher, for some lower. Obvisouly, it can never be over the main mass of an object. So the rotor head is not the point of rotation / center of gravity as your pictures make us believe.
And I can not up vote a wrong assumption. Show us the exact center of gravity of the in-game model (not a picture mock up) and the one of the real counterpart and we can talk differences. This is pure speculation on your end.
First, I take scientific evidence seriously and your video only support this ticked as it shows pendulum like effect in helicopter where the fuselag hangs from rotor and swings from the hanging point.
And I don't know how you can claim that the original post has only _one_ helicopter, as there is two.
Yes, you are not aviator. You can't correct wrong physics assumptions because you don't know how helicopters should act. You can not just take a one laws of physics and say "This is so" as there are so many that you should spend few years understand them.
This ticket is about ARMA 3 to get a more realistic helicopter physics with its very limited flight modeling. This is not request that BIS should design a more complex flight modeling to achieve the better feeling, simply just adjusting the current wrong modeling, what even older and simpler flight games have fixed and has basic flight modeling closer very complex simulators.
If you understand the ticked, I don't claim that CG (Center of Gravity) is in main rotor, only that the rotating should happen from there with ARMA 3 very simplified flight modeling to achieve a better feeling for flight from its current very arcade and wrong kind flight modeling.
The mockups shows from two helicopters where is the pivot in game (red dot) and its motions (arrows) and where it should be (green dot) and its motions (green arrows).
And you have already voted with your assumptions that helicopter will rotate around CG and it would be somewhere middle of fuselag, and it is wrong by helicopter physics because there are lots of other forces than just the fuselag mass and they are the ones what makes flying possible and every time those one of those forces is increased or decreased, other force is effected by that and new cause is created.
As CG can be anywhere in or outside of helicopter, and helicopter could fly. CG only transfers the hanging point line from center of mast to other point, this way limiting the cyclic controls effectiveness, forcing pilot to apply extra cyclic.
The mockups show you the CG in game models and where pivot should be by ARMA 3 current flight modeling, without requiring to rewrite the game engine.
And you know very well that Mi-48 does not exist so your demands are worthless. from that part.
And I have given links to videos comparing ARMA 3 and various other helicopter simulators (and even old arcade game). Others have as well given links to videos what shows the helicopters pivoting from above the fuselag from main rotor and even your own video shows it as well if you just would look carefully enough and not just stare theoretical CG point and forget that there is a huge, many times heavier rotating and tilting disk above fuselag.
You don't even seem to have ever flied any of helicopters in ARMA 3 as you would already have found their flight model being wrong.
Question: Do you really claim that ARMA 3 follows the correct physics, that BIS has just managed to model laws of physics correctly, but then ED has just typed something pure speculative to their simulator? http://youtu.be/bC1MgXnqMnI & http://www.youtube.com/watch?v=J3LJ5R-Zi3U
As you said, you are not aviator. You don't know how it feels to sit in helicopter. Or how a flying helicopter reacts to your inputs. Or how you need to give input to helicopter reactions. ED has managed to get it well, BIS did not. Even BIS TOH "simulator" is so wrong by many basic modelings.
I just don't fully understand why people are against correct modeling when in current ARMA 3 modeling it is like the hinge and rod from pendulum are what swings around the mass.
It would make flying harder, require player to understand more about helicopter flying than the current modeling.
The new setCenterOfMass scripting command can be used as a work-around for this issue now (at the mission design level). For example, setting it to [0, 0.5, 1] on the A/MH-9 results in more realistic pitching/rolling behaviour.
See:
http://www.youtube.com/watch?v=ug76TCVsvrA at 0:24
http://www.youtube.com/watch?v=QijetGUlJ4A
http://www.youtube.com/watch?v=7ayGr7bWIg0
http://www.youtube.com/watch?v=uYbx5H5e9Es at 0:48
http://www.youtube.com/watch?v=j-piEL58hsg at 0:38
Sorry to spoil the fun, guys, but OP is wrong and will be wrong. MadDogX, I didn't expect that you will fall for that.
New duplicate of this ticket: #15688
@DarkWanderer it is just sad that you have not yet learned that helicopters are not freely moving vehicles (6 axis) but they have much more greater force what you don't count above the COG. Helicopter simulators renders the rotating axis in most cases above the fuselag, even when COG is below rotor head because dozens of other physics what you don't want to include.
You don't want to count in thrust, velocity, drag etc what cause helicopter not to rotate around COG always.
You don't neither want to accept the fact that in helicopters COG moves all the time and it doesn't change the helicopter flight characteristics even if the COG is placed above the rotor (like upside down flying or if you would move fuselag above rotor) and the helicopter flies same manner but requires only pilot only to mirror every control input (when you want down you raise collective, when you want to roll right you move cyclic to left, when you want to pitch forward you pull cyclic).
http://youtu.be/J3LJ5R-Zi3U
http://youtu.be/bC1MgXnqMnI
Can you spot the thing? Rotating Axis isn't in center of mass or where the center of gravity at given moment is. Do you know why?
Your opinion was that BIS made great flight modeling for Mi-48 in ARMA 3 because rotating axis is almost center of fuselag, what translates DCS, X-plane 10, Flight Simulator 10 and many other have done helicopters totally wrong by your believes because they behave totally different as you say.
From science point of view, you are not accepting problem here what even a simple helicopter game decade (Gunship!) ago fixed without any complex physical modeling like modern helicopter simulators applies and doing so simply placing a fixed rotating axis on rotor head where it is in most cases and it gave better flight experience.
ARMA 3 flight modeling is a single virtual point in game space what is moved like basic physics book is told to happen in space, without considering all the forces what should be affecting to that "point".
Even in your videos helicopter behaves like I have told and given examples from helicopter simulators. Remember, I am not saying that helicopter does not never rotate around center of gravity or center of mass.
You really argue helicopters should rotate around the middle axis of their fuselag while it is done only in ARMA 3 all the time.
@MadDogX "For example, setting it to [0, 0.5, 1] on the A/MH-9 results in more realistic pitching/rolling behaviour."
I can confirm that setting for vehicle does dramatically change the feeling of helicopter behavior. It clearly isn't anymore like flying a "paper" with odd input dampening but it gives feeling like more weight is added to helicopter.
I found next settings a good start (giving just about 30s with each listed helicopter):
(For those who don't know how to test settings, I have named each helicopter model with its own name like "ah9" or "ah99" and then given the execution code as whole line is)
For AH-9 Pawnee between (too high input what causes very rapid helicopter movements)
ah9 setCenterOfMass [[0,0,1.4],0];
ah9 setCenterOfMass [[0,0,1.6],0];
For Mi-48
mi48 setCenterOfMass [[0,0,3.9],0];
For AH-99
ah99 setCenterOfMass [[0,0,2.5],0];
For UH-80
uh80 setCenterOfMass [[0,0,2.8],0];
For PO-30
po30 setCenterOfMass [[0,0,1.9],0];
It is wonderful to have a change to test different center of mass (!= COG) and even ARMA 3 has so simple flight modeling (considering game engine age etc) the raised rotating axis made huge difference for flight modeling on helicopters.
I strongly suggest to make default COM on each helicopter higher so everyone could enjoy from more realistic feeling flying a helicopter.
Tomorrow I might have time to test more and find a more pleasing values for each helicopter what at least I am starting to use in every mission because improved realism.
Use
setCenterOfMass command and bring it up to achieve effect described in OP. The problem is that the centre of gravity cannot possibly be that high.
EDIT: just noticed it was already suggested