Page 2 of 3

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 15:21
by autogyro
Lighter than air is an interesting take on the project.
It would be unbeatable if the rules allow it.
I think the idea was for heavier than air vehicles though.
The econoplane would be interesting and the comparison with other types would be useful to aero guys.

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 21:02
by TheMinister
I should have known you guys would instantly come up with a series of ideas, all of which are banned (or shot down by my teammates- I wanted to do the autogyro, but they said it'd never work). Lighter than air gases, combustion, etc....

Perhaps I need another go at selling them the autogyro. Or just go ahead and have my own, seperate entry :twisted:

Any more thoughts on the original concept?

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 21:12
by machin
Why aren't there more unpowered rotary wing aircraft if they're so good? Because of the complexity? Or patent protection? I'm intrigued by this suggestion...

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 21:32
by autogyro
machin wrote:Why aren't there more unpowered rotary wing aircraft if they're so good? Because of the complexity? Or patent protection? I'm intrigued by this suggestion...
Simple answer that is 100 percent true.
The American helicopter manufacturers, aviation and arms industries, prevent any development in unpowered rotor craft here in the UK and overseas. In the UK Westland is established as the ONLY rotor craft manufacturer and it ONLY license builds American designs and has done so since the 1960s. It is the most blatant and corrupt manipulation of the British legal and political system for personal gain, probably in history.

The CAA in the UK does not even have a definition of unpowered rotor flight (autogyro), it also has nobody on its staff who even knows how an autogyro flys.
We asked for such a definition so as to update the CofA already given to the Wallis W116 by the Air Ministry. We were told that we could do so if we paid millions of pounds to establish the definition ourselves.
The British Government Cabinet Office has been approached and continues to avoid the issue as do all the other Ministries.
In the 60s the UK had a proven in service short and medium haul autogyro airliner that needed NO runways and was far more efficient than any helicopter, the British government not only scrapped it they destroyed everything left of the aircraft to preven anyone remembering it.
Ken used to fly with this aircraft at airshows.
http://www.youtube.com/watch?v=X4AIVAz0 ... re=related

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 21:38
by autogyro
TheMinister wrote:I should have known you guys would instantly come up with a series of ideas, all of which are banned (or shot down by my teammates- I wanted to do the autogyro, but they said it'd never work). Lighter than air gases, combustion, etc....

Perhaps I need another go at selling them the autogyro. Or just go ahead and have my own, seperate entry :twisted:

Any more thoughts on the original concept?
Ask if they know how an autogyro flys, that should result in an interesting set of answers.

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 22:31
by Arunas
autogyro wrote: Ask if they know how an autogyro flys, that should result in an interesting set of answers.
That is a good question. I'm not sure if I understand it correctly. Must look somewhere for answer.

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 23:11
by machin
thinking about it logically; forward motion of the vehicle causes more drag on the blade facing away from the direction of motion than the blade facing into the direction of motion (assuming 2 blades). This causes the rotor to rotate in the right direction (ie leading edge first) This rotation and forward motion of the vehicle itself means the blade velocity is higher than for a comparable fixed wing aircraft... Hence more lift...

There must be some disadvantages though?

Re: Ground effect aircraft efficiencies

Posted: 09 Nov 2010, 23:22
by machin
Ok, so how about this (more car related than the original porter's question) instead of fixed wings like a current F1 car how about a number of (upside down) autogyros attached to the car? Not legal with the current F1 rules I know... But would it work?

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 02:15
by autogyro
machin wrote:thinking about it logically; forward motion of the vehicle causes more drag on the blade facing away from the direction of motion than the blade facing into the direction of motion (assuming 2 blades). This causes the rotor to rotate in the right direction (ie leading edge first) This rotation and forward motion of the vehicle itself means the blade velocity is higher than for a comparable fixed wing aircraft... Hence more lift...

There must be some disadvantages though?
Partly correct but our twin bladed rotor does not have an articulating rotor head like a helicopter rotor, it has a 'teeter bearing' head of brilliant concept, that varies the angle of incidence of the blade depending on where it is around the disc. The result is a totaly balanced lift device that converts forward motion through the air to lift with almost no drag resultant.
It is nothing like how a powered rotor works. Unlike a helicopter the autogyro is the most stable aircraft their is, capable of flight in 70 mph winds. It can easily be trimmed to fly both hands and feet off, compared to a helicopter which is a constant juggling act on the controls. One pilot can fly it and easily undertake the use of role equipment including weapons systems.

http://www.youtube.com/watch?v=M9WXPsqEy1s

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 02:19
by autogyro
machin wrote:Ok, so how about this (more car related than the original porter's question) instead of fixed wings like a current F1 car how about a number of (upside down) autogyros attached to the car? Not legal with the current F1 rules I know... But would it work?
I dont see why not. Interesting design challenge.
High downforce with low drag, might be worth looking at for a performance road car.

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 16:30
by autogyro
machin wrote:Why aren't there more unpowered rotary wing aircraft if they're so good? Because of the complexity? Or patent protection? I'm intrigued by this suggestion...
Sorry to bring this up again but it is important.
Take a look at the wiki link on autogyro flight.

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

Take a good look at UK certification (which are absolutely crazy and based on a complete ignorance of ag flight and a need to prevent development)
Compare them to world records underneath.
If this does not confirm the corruption nothing will.

Ken Wallis agrees with me that ALL light autogyros in the UK should be grounded until a proper workable definition of AG flight is established in a new set of regulations drafted by people who know what they are talking about.

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 18:05
by flynfrog
the one problem with the autogyro would be the take off distance. Im not 100% certain how that scales but you could burn a decent amount of battery just getting the rotor up to speed. Admittedly autogryos are not my thing but I believe this was a problem with them.

As much as I like the out of the box thinking a light built powered glider is probably the best idea here. Even better if you are outside on a warm day.


sorry the MFG eng part of my brain kicked in. What about the complexity of trying to manufacture the rotors on this scale. It might be hard to scale down the weight savings. Also you can buy a prop from the hobby store not so much a gyro rotor.

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 20:12
by Arunas
Just for my knowledge: has autogyro something i common with perpetuum mobile?

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 21:55
by autogyro
flynfrog wrote:the one problem with the autogyro would be the take off distance. Im not 100% certain how that scales but you could burn a decent amount of battery just getting the rotor up to speed. Admittedly autogryos are not my thing but I believe this was a problem with them.

As much as I like the out of the box thinking a light built powered glider is probably the best idea here. Even better if you are outside on a warm day.


sorry the MFG eng part of my brain kicked in. What about the complexity of trying to manufacture the rotors on this scale. It might be hard to scale down the weight savings. Also you can buy a prop from the hobby store not so much a gyro rotor.
Unpowered rotors are not the same as airscrews. On an airscrew the aerofoil section varies in shape size and angle of attack from center to tip and the mounting is either rigid or through a reduction gear.
Wallis unpowered rotors use the same aerofoil section throughout are of much higher aspect ratio, they have a fixed blade length angle of attack but a radialy variable angle from the head and are mounted on teeter bearings to balance lift and drag around the disc and allow collective rotor control.
Rotor spin up is achieved using a friction drive on the engine crankshaft driving a small epicyclic gear on the rotor head via a cable. It is disengaged on take off. Rotor spin up can be achieved in a decent wind or by taxying. With spin up take of is around 7 feet in still air or VTOL in a +7 knot wind.

You are correct regarding scaling however, it is difficult to achieve a good result in miniature much as in scale rc fixed wing models.

Re: Ground effect aircraft efficiencies

Posted: 10 Nov 2010, 22:28
by machin
Whilst it might be difficult to make things on a small scale at least u have the advantage that whilst weight is proportional to volume, lift is proportional to area.

How does the take off distance of an autogyro without pre-spinning compare to a normal fixed wing aircraft? Pre-spinning sounds like a step too far for this guy's project....