In the video you will be able to see how the helicopter is flying without the rotor blades spinning.
Click ‘more’ to see an additional video
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What the ????
why do you post this crap? A helicopter can’t fly without a rotor. DU loses more and more value to me every day.
This looks like a case of photoshop Aerodynamics??
It’s an effect of Persistance of Vision (the effect that allows for seeing animations). If you were watching these helicopters in person, nothing would seem odd. The human eye has a very fast refresh rate, but many cameras do not. Ever point a camcorder at a TV or a computer monitor? The black bars are “created” by the camera’s inability to use persistance of vision. You can hear the rotors spinning, you can see the tail rotor spinning, and as the engine changes RPM slightly, you see the main rotor move slowly.
Cool! Sorry boys and goils, but all this is, an optical illusion, rotors appear stopped and the frame rate of the video and rotor rotation are in sync….
now for some real stopped rotor helicopter pics (sorry no video)
http://www.answers.com/topic/sikorsky-s-72
Problem is with current stopped rotor tech, is the material strength isnt there yet… oh but to have one these!!!! :P~
A helicopter can fly without a rotor, Erik. The downward thrust-vectoring nozzles at the end of each wing-let are obvious in both videos. Very impressive actually, considering a Harrier jet, which used similar technology, can barely move while hovering.
#5 – The MI-24 helicopter has been flying for at least 30 years. Those winglets are for weapon pods, and on the end is just another hard point for mounting weapon packages. #4 is absolutely correct with the optical illusion explanation. I am surprised that anyone fell for this, especially someone as normally savvy as the DU admins.
#4, AdmFubar, thanks for the link. That Sikorsky reminds me of the cool choppers in Arnold’s movie, “The 6th Day.” As I recall, ‘The Governator’ was a pretty good pilot in that one.
Wonder how the camera synced precisely with the main rotor? Very cool. Almost looks like a Harrier maneuvering.
I think the comment about this being an optical illusion are on the money. Listen to the soundtrack – you can hear the rotor blades thwack-thwack-thwack as it moves around and you can also hear the throttle being opened up. A bird this size would only be able to do a controlled landing (well, they’d call it controlled – it’ll be more like a survivable crash!) with the main rotors out….
“A helicopter can fly without a rotor, ” Not this one, Robert.
Frame rate is how this was done. If the rotors were stopped the blades would be drooping down not up and the tail rotor would be stopped too!
As for a “Vectored Thrust”, Where is the engine and where are its intakes & exausts and since when did they have a Vectored Thrust engine that big?
There are lots of other give aways.
Slatts
(Aeronautical engineer.)
#2 – You should know by now that DU is not always serious.
…and #5, you are the new recipient of the Ultimate King Kahuna Moron Award!
Man, this is awesome beyond words! It’s a perfect sync!!! Unbelievable! I was like for a minute or so wondering – what the heck is going on here?!?! I’ve heard about helicopters gliding in autorotation, but never with rotors standing perfectly still, so this is frakin’ awesome!
hehe, yeah, obviously doctored
reminds me of that movie “ConAir” where an airplane somehow flew down a street knocking down light posts with its wings – riiiiiight 🙂
10. hhopper, I know I’m late but you cant give away the award yet, I say its been suspended from a UFO, you can see the wire if you look real close. Now, where’s my damn award?
Sure saves on gas!
It appears that the numbering of posts on this topic is completely whacked, perhaps off by 1?
Harrison, the Ãœber Ultimate King Kahuna Moron Award should go to the person or software responsible (and the student cheater in that previous article).
Sorry Mark, you’re too late.
I just want to know what kind of video camera they used. Each frame is like a perfect still 1/1000th of a second exposure image. With standard NTSC scan rates, they would still blur a little with the tips traveling faster than the hub. At the tips, the blades are doing a couple of hundreds of miles per hour.
Heck, old Huey blades are going nearly supersonic (thereby creating the “whop whop” sound). Of course, larger diameter rotors with multiple blades have a much slower tip speed but this is still very impressive to catch them without any blur whatsoever.
It must be a new digital camera that works like an SLR or something. It looks like every frame is a still image grab instead of a horizontal scan. Impressive!
#18 Pro cameras have had selectable shutter speeds for decades…
It’s the fact that it’s a amateur camera that blows my mind…
Damn, this kind of gear is gettin’ pretty good…
#10, Slatts observation about the main rotor supporting the weight of the chopper is dead on.
#18, Mark T., after watching several times, I wonder if the main rotor tach was somehow synced with the camera frame rate via radio? Watching the flight path and maneuvers (and the tail rotor), the main rotor speed had to vary.
That’s about the only way I can figure how this was done (well, without a boatload of photoshop work.) Great puzzle. Thanks, Gasparrini.
It’s a model of a HIND imposed on amature video of empty sky over an air field.
Seriously, I have no idea.
It is obviously a syncing issue with the camera frame rate. Observe the rotor tips, particularly in the turns when their would be enough deflection to cause each rotor to take a slightly different angle; you will see that they blur more than a little bit, from this effect. Nice vids, though; I’m sure the camera owner was a little surprised when he replayed the video the first time.
Anyhow, if I were going to build a fancy antigravity ship, it wouldn’t need to look, let alone sound, like a helicopter.
You can hear the blades hitting the air…. It is obviously an optical illusion…
It is not a syncing issue. Notice the shadows of the rotor blades on the helicopter. In the second video, notice how the rotor blades arc up due to lift just like the wings of a glider. The rotors are NOT moving.
The old high shutter speed strobe trick. Heli version of the stagecoach stationary wheel trick.
How interesting to learn that the position of a blade during these maneuvers is so closely indexed to the position the previous 1/60 or 1/50 sec (depending on whether the original was NTSC or PAL video format).
So many video cameras have the option to use high shutter speeds, and usually helicopters don’t look good at 1/5000 or 1/10000 sec, but this is the exception.
If the blade moves 72 degrees (1/5 of a rotation) in 1/60 or 1/50 sec that means the whole set is spinning at 12 rps or 10 rps. Is that typical? Could this be the product of a 30p or 25p video camera plus high shutter speed, suggesting 6 rps or 5 rps? Or was a variable frame rate camera involved, inching up on the strobe frequency?
Further to all comments –
What impresses me is how stable the rotor speed is in manoeuvres!
Any helicopter I know of would have noticeable variations in speed.
If you look closely you can see the rotors move back a bit when it pulls in power but I from a professional point of view you have to admire the engine fuel system designer.
Eurocopter –Take note 🙂
Slatts
Bubbaray, the rotor blades and engine speed on modern turbine helicopters operate a constant speed. That way the engine works at its peak efficiency and there are no spikes in the torque curve. You set the engine speed/rotor rpm once although you may have to tune it later for altitude change (air density), cruise, etc.
All the maneuvering is handled by the pitch of the blades and not the RPM of the rotor. This video effect is about what you should expect.
Oh, you are right @$tr0Gh0$t. It’s David Blane’s helicopter and it is actually gliding vertically!
#28 (Mark T.), good job on not offering a rebuttal to the fact that THE SHADOW of the rotor blade is STATIC.
The strobe effect is going to work on the shadow as well as the blades.