Why do the rotor blades on US helicopters rotate a different way to all other countries helicopters?

Question

If looking from above, US helicopters blades rotate clockwise but helicopters from all other countries (apparently) rotate anti-clockwise. Is this true and if so, why?

Thanks

Answer 1

I didn't know that.  Are you sure?

Besides, the helicopter was invented in USA.  So it is everybody else who got it "wrong".  Ask them.

Good Luck...

Answer 2

Well, when they rotate clockwise and you add power you use right pedal.

Sooooo, maybe they figure pilots transitioning from Fixed wing would have less of a problem? Only a guess tho'

But it is no problem for the experienced helicopter pilot as you use the pedals "as needed".  

I jumped from Bells to "A" Stars the same day and never experienced any problems.

Answer 3

america is backwards

Answer 4

they don't. some manufatured in the us rotate clockwise, some counter clockwise. sikorski, counterclockwise, robinson, clockwise for instance. the direction matters not but i do wish everybody would get together on this. makes a difference which pedal you push when pulling pitch.

Answer 5

Americans obviously insist on being different in everyway from the rest of the world

probably another reason for them to stand out from the rest

Answer 6

All cameras have a 'frame rate' .. this matches the TV rate .. in USA this is 60 frames a second. In UK and most of the rest of the world it is 50 frames ...

Now (believe it or not) most documentaries shot in USA are likley to be made using US cameras and 60 frames a second .. needless to say, this has to be processed (sub-sampled) before being shown on UK TV ...

This can lead to a 'strobing' effect ... (look it up)

NB> Faraday got it wrong :-)

Answer 7

What about the Chinook  (it has 2 rotors going in opposite directions )

http://en.wikipedia.org/wiki/CH-47_Chino...

Answer 8

First, let's get some facts straight.

In general, US helicopters rotate counterclockwise when viewed from above (you said clockwise).

It is also true that Russian and many European helicopters rotate clockwise (and it's not just the Puma).

Helicopters with two main rotors will always have them rotating in opposite directions.

The helicopter was not invented in the US. However, Sikorsky, Bell, and others did make the first production helicopters and deserve much of the credit for refining the helicopter design and making it practical. See the following:

http://www.vectorsite.net/avheli_1.html

http://www.centennialofflight.gov/essay/...

http://en.wikipedia.org/wiki/Helicopter

Robinson helicopters do rotate counterclockwise as well. Check out the first part of this video of a R44 starting up:

http://www.youtube.com/watch?v=XU5-Voopn...

Now, to the matter at hand. I did find one article on the question here:

http://www.aerospaceweb.org/question/hel...

The first thing you will notice is that it is not just Americans who make helicopters that rotate counterclockwise, despite what a few completely ignorant and asinine answers on here would have you believe.

I would add to what this article says that the helicopter was developed independently by many pioneers all over the world. This process happened over the course of many years, and that development happened a long time ago. The idea that someone decided to do things differently because they wanted to be different from other nationalities is ludicrous. The initial pioneers made their aircraft one way or another, and subsequent designs just followed that convention. It is just a coincidence that some developed theirs one way, and others made them the opposite.

I agree with John B that it would be nice or them to adopt one global standard, but manufacturers like Bell and Sikorsky have been doing it one way for decades, and they will have little incentive to change. The directions are merely an inheritance from the arbitrary decisions made by early pioneers, and it looks like we are just stuck with differing conventions.

One other interesting thing is that Sikorsky's VS-300 had a clockwise rotor as you can tell from the direction of the leading edges in these photos:

http://www.sikorskyarchives.com/vs300iis...

His subsequent R-4 model had a counterclockwise rotor.

Answer 9

Because they're Americans.

Did you know that Michael Faraday had already determined which was positive and which was negative and that the system had been in use here in UK for more than 100 years.  Guess what, along came the Yanks and changed it around just to suite their system.

Likewise when it comes to numbers - according to the Yanks a billion = 1000 millions - dud!  not in English it don't - here it used to be 1-million millions = 1-billion - so now we're all living in a Yankee-Doodle-Dandy reduced world.

Duh!

Answer 10

They don't. The only Helo who blades rotate the other way to all the rest is the French/Brit Puma. All other rotate in the same direction.