Cool picture, huh? Wait until you see the video footage of this LED-adorned RC helicopter flying on a dark night. But this isn’t an art project. Analyzing the long-exposure photography turns out to be a great way of clearing up some of the physics of flight which otherwise are not at all intuitive. The helicopter used here has different colored lights on the nose and tail, as well as lights on the rotors.
Depending on how the aircraft is moving, different 3D spirography is captured by the camera. When you zoom in on part of the flight path it becomes clear that there are wider arcs on one side of the fuselage than there are on the other. This has to do with the forward progress of the aircraft and the rotation of the blades. The phenomenon is well known by helicopter enthusiasts, and accounted for in the design. But what we didn’t realize is that it actually translates to a theoretical speed limit for the aircraft. Our childhood love of Airwolf — the TV helicopter that could outrun jets — has been deflated.
You should remember the helicopter physics videos featured here last month. This is the latest offering and we’re still wanting more!
[via Reddit]
I’m pretty cetain airwolf had turbo jets on the side of it. nice video, gonna remix it.
It did, but the returning blade loses its lift when the forward speed of the heli is higher than the speed of the blade.
And due to the vibrations caused by breaking the speed of sound will cause damage to the blade, the end of the blade has to travel at speeds lower than the speed of sound, so the lift the blade has to supply would not be sufficient even long before the heli reaches mach 1.
You will also get more lift from the blade going forward, so you will actually get pretty much the same lift, but you will not have control of that lift, and that control is pretty much what makes a heli flyable.. :P
betcha there were tons of ufo sightings in your area that night. i like how the physics play into it as well. the light gives the relative position of the forces exerted on the heli.
Awesome footage, awesome video! The physics of helicopter flight is a complex subject, and they’re doing a good job explaining it.
The state of top-end RC helicoptors and their pilots nowadays is nothing short of amazing:
http://www.youtube.com/watch?v=jDZ2YvY6HiI
if the helicopter could get through the sound barrier, so both wing tips were above mach1, would the destructive shockwaves cease and the copter still be able to fly?
The long shutter shots look great but you know what would make them even better? two cameras with long shutters to get 3D images, now that would really show you the flight path the helicoptor took.
I was a huge fan of “Airwolf” as a kid. To the point that I eventually grew up and became an attack helicopter pilot in the military. During flight school I was a bit disappointed that the physics behind rotary wing flight made an aircraft like Airwolf practically impossible. I was pleased, however, when I went back as a pilot and watched the first season while I was on deployment in Iraq.
Airwolf actually addressed the retreating blade stall issue in the show. They mention that the rotor system actually disengages from the transmission, allowing it to spin freely. The fuselage of the aircraft is aerodynamic and produces its own lift, with all thrust being provided by the “afterburners.” Unfortunately, the “afterburners” are activated by pressing the Force Trim button on the cyclic…..
This does not mean that it is feasible or even possible to break the sound barrier in a helicopter, unfortunately.
Helicopter technology has come a long way, though. The Sikorsky X2 is insanely fast. I was able to check out the prototype and have a long conversation with the senior test pilot. They can slow the main rotors as forward airspeed increases and forward thrust is provided by a push-prop in the rear of the aircraft, with the fuselage generating lift. Sound familiar?
It’s no Airwolf, but it’s still pretty sweet.
http://en.wikipedia.org/wiki/Sikorsky_X2
More geeky side of the X2 aerodynamics (kind of old):
http://www.unicopter.com/1465.html