Air jet helicopter

[steveh]

Greetings,

 

I'm new here so hello everyone.

 

I just came across this video of a helicopter that uses compressed air to drive the rotors rather than a shaft. It looks great , so why isn't it in production ? Are there any drawbacks in design, or just inertia from the industry ?

 

[r870]

Here is some discussion on it: https://www.quora.com/Why-are-tip-jet-helicopters-so-rare-even-though-it-doesnt-seem-very-complex-and-would-work-fine-with-current-engines-like-turbines-or-any-kind-of-compressor

 

Basically, engineering complexities leading to high costs, very high amount of noise produced, and low fuel efficiencies are the major drawbacks, with few advantages to offset these disadvantages.

[500E]

Suggest you look at Pegasus helicopters, there are posts on this site also the web site(google)

The Sud-Oust Djin was the only machine of this type to reach service I think

[TomPPL]

theres more here:

 

and here:

http://www.aviastar.org/helicopters_eng/snias_jinn.php

[Wally]

I forgot about the Djinn. The Fairey Rotodyne was not strictly speaking a helicopter, but my memory is that they were both LOUD! not fuel efficient. Having nozzle mass at the tips would provide excellent rotor inertia in the auto...