I bet with my dad that there is a helicopter with only one rotor on the top, am I right?

Question

My dad said it should have another propeller on the tail.

Answer 1

You are correct. MD Helicopters produces 3 models that have NOTAR (short for NO TAil Rotor) technology. The torque effect created by the engine powering the main rotor shaft is counteracted by thrust produced around the aircraft's tail boom in a phenomenon known as the "Coanda Effect". A high-volume fan contained in the root of the tail boom pushes air that is directed out through two slots along the right side of the tail. This airflow channels the aircraft's own downwash into an airfoil shape around the tailboom, thus producing a side-thrust which counteracts torque. Their website has a pretty good explanation:

http://www.mdhelicopters.com/page.php?cid=1&id=company

Answer 2

Yes there is as someone else explained previously. Mc Donnel Douglasa Aircraft co. Have some modified MD-500 helicopters which use thrusters in the tail-boom to counteract the torque spin produced by the main rotor. Most helicopters use a tail rotor t oresolve this problem. Some others use a ducted-fan as a "tail-rotor" to solve the problem. So technically, the NOTAR system equipped helicopters are not the only ones that have only one rotor because you can't really call a ducted-fan a rotor.

Answer 3

Here's the deal. A traditional helicopter, one with a single main rotor system that is driven by an engine or engines in the fuselage, needs some kind of tail rotor to counteract the torque generated by the engine spinning the rotor blades. Imagine yourself in that vomitous Teacup ride at Disneyland. When you turn that wheel in the middle clockwise, your teacup spins counterclockwise. There are new designs that use the engine exhaust forced through ducts in the tail boom to generate the same thrust, so that a tail rotor and all its complex parts are not needed. Those twin-rotor helicopters you see with rotor systems on each end or stacked one above the other have counterrotating rotor blades that cancel out each other's torque, thus making a tail rotor or other mechanism unneccesary. What a lot of people don't realize is that there is a type of rotor blade system that's been around for years, but not widely used outside of experimental aircraft, that has jets on the tips of the blades that spin them, so there's no engine generating torque to spin the fuselage the opposite way. These are the only true single-rotor helicopters that don't need any kind of tail rotor or forced-air thrust to keep them flying straight. This means that you are right. Here's a picture of one, and a little information.
http://www.nasm.si.edu/research/aero/aircraft/hiller_hoe.htm

Answer 4

Or are you asking about a helicopter with only a single blade or airfoil on the rotor - It was proposed experimentally by Sikorsky, designated the XV-2 also XH-36. Scary design, never built. One blade, counterweight, no tail rotor.

Answer 5

The definition to a rotor.. is the machine that rotates the blades.

There must be some sort of counter rotation to the main rotors... either a tail, dual rotor, or cunter rotatin on the same axis.

Either way is is required to have some type of counter rotation... one rotation is impossible to control

Answer 6

Apparently, such a helicopter exists, but it seems like it was somewhat experimental, and was never put into service.

Note that not all copters have tail rotors; some have 2 main rotors spinning in opposite directions.

Answer 7

Yep, there is one that I know of, it's a higher speed helicopter, not so much hovering like some of the tail-rotor equipped helicopters can do.

Answer 8

You are right, there is a type of helicopter call NOTAR, or no tail rotor. Several McDonnell Douglas helicopters utilize this design.

Answer 9

There are some older versions with only one rotor on the top. In these the pilot flew it in standing position instead of sitting on a seat.

Answer 10

The latest design copters have thrusters in place of the tail rotor.
But ya gotta show respect for your Dad; don't shove this under his nose..