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Post by jcomm on Nov 6, 2008 4:49:29 GMT -5
Hi Guys! Long time no post... I wasn't aware of this new forum, and kept trying to figure out why the old one was permanently under maintnance... Today I finally glimpsed the new link --- DUH! Well, I would like to hear from you if something like the accident in the video here www.youtube.com/watch?v=XRCbkBfdBrQcould happen in RL. I've been thinking about it and I believe it could. An airplane (not a delta wing of course...) without an horizontal fin and elevator will not fly, but what about one without a wing? |
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Ed Burke
Member
Healthy living is fine, but it's having fun that keeps us going!
Posts: 433
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Post by Ed Burke on Nov 6, 2008 7:36:16 GMT -5
I've been studying that vid for days now, in fact I have sent it to bods all over the planet and it just blows me away.
That 'knife edge' flying is every day stuff to aerobatic pilots in a/c like the Edge etc. This guy had the split second judgement to be able to get the machine back on the ground without rolling it into a fireball. Ok, so he had plenty of incentive to do the job, but what a superb piece of flying. Note the huge control input into that full span aileron as he gave up flying.
Could happen in RL ? No, DID happen in RL. Moral is to check your wing attachments before you try a Lomcevak.
Ed
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Post by jcomm on Nov 6, 2008 9:18:32 GMT -5
I've been told the video is fake...
Looking at it with care, specially the last seconds before touchdown suggest the image has benn edited.
I am not sure of course but the fact is that at my soaring forum here in Portugal it raised a lot of comments regarding the possibility of this really happening to an aircraft of that type.
Of course if we were sure about it being true the answer was already given, but many doubt it is....
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Post by Tom Goodrick on Nov 6, 2008 10:57:22 GMT -5
I do not have, and cannot install, the proper software to run the video. I gather the wings came off and the pilot was able to rotate the fuselage to fly in the "knife edge" orientaion to make a survivable landing. It is not clear to me whether there was any power. Some comments seem to indicate there was propeller power.
The most likely scenario as described in some of the comments is that it is a video of an R/C model. The model would be much stiffer than a real plane and would not break up on landing. It is hard to imagine any real plane not breaking up if landed on its side with no wings at a high speed.
Some of the comments about lift and angle of attack are ludicrous. Neither lift nor angle of attack pertain soley to the wings. Any arbitrary shape has lift and angle of attack relative to the air it is moving through. Lift has no preferred orientation - up, down or sideways but is oriented within the same plane as the angle of attack by definition.
I have done some research on arbitrary bodies immersed in airstreams. Generally they rotate and tumble which gives radically different aerodynamic forces and moments. But tail fins would stabilize the fuselage and would enable a pilot trained in aerobatic flight to hold the fuselage so a side is up and there is an angle of attack maintained in the vertical plane (geometric, not airplane).
Think of lift as just one of three aerodynamic force components acting on a body in general. The orientation of these force components is defined according to the plane of the angular displacement we call angle of attack - between the relative wind and any surface that has some flatness.
This all says that, yes indeed, the fuselage side can generate lift. The problem is its lifting area is very small compared to the wing area so it must be going quite fast to generate lift on the order of the weight. Aerobatic planes seldom do this. They lose altitude and can only do the knife edge for short distances before flipping erect and gaining altitude. They do get help in holding altitude from the prop thrust. But you can't have both good lift and good upward thrust. As more upward thrust is held the fuselage stalls out and lift decays. Unlike a wing with a typical airfoil, a rounded body generating lift will not lose it abruptly in a stall.
There are many problems in dynamics, of course. With the wings gone the moments of inertia are very low about the roll axis and lower than usual about the yaw axis. Thus the aircraft could not do well in resisting prop torque. You'd get fast roll response to the torque and slower yaw response, both poorly controlled. Cutting the engine would be the only way to attain control.
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Post by Allan_Lowson on Nov 6, 2008 14:59:58 GMT -5
After a bit of rooting about I came across this site: www.hoax-slayer.com/one-wing-plane-landing-video.shtml- it would appear that this is an elaborate hoax intended to make you buy clothing from the sponsors of the aircraft! Have to say it is skilful editing of the apparent incident. After repeated views a couple of slightly suspicious points show up. The aircraft is supposed to be a Red Bull racing series aircraft - except the pilot seems to be an unknown in the field! When the single-seat aerobatic aircraft is coming in to land in a left wing high knife edge - having lost the entire right wing in flight - the rudder appears to be deflected to the right and I would have expected full left rudder to keep the nose up. When bouncing a couple of times during the landing the "pilot" seems to keep very still in the cockpit too. Goes by the name of viral advertising I am told. |
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Ed Burke
Member
Healthy living is fine, but it's having fun that keeps us going!
Posts: 433
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Post by Ed Burke on Nov 6, 2008 16:15:16 GMT -5
Oh well ! It really looks to be the goods although the masses involved with a real aircraft would probably have made the touchdown a bit less lively. As for the rudder input, it is only briefly centralised as the nose, and the angle of attack, got very high. As the aircraft stops only the left side is visible and the shadows are conveniently difficult to sort out, a good piece of work by whoever.
On Youtube there is a vid of a large model doing just this very landing although the model briefly stood on its nose.
Ed
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Post by jcomm on Nov 7, 2008 7:04:48 GMT -5
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Post by hanspetter on Nov 12, 2008 20:23:36 GMT -5
I do not have, and cannot install, the proper software to run the video. I just checked and Adobe Flash player 9 should work under Windows 98. There's an internet explorer requirement (version 6) or a recent Firefox, Mozilla or Opera. It should be possible to watch Youtube videos under Win 98 but the flicks may take long to load over a dial-up connection. |
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