Hiller Flying Platform

[rotorque]

Does anyone out there have any idea how the Hiller Flying Platform got its lift. And if it uses some form of rotor or ducted fan how did it cancel out torque. Great invention - should of been adapted further.

Cheers

[Lu Zuckerman]

To: Rotorque

I saw one demonstrated at Fort Eustis Virginia back around 1956/7. From what I remember, it was powered by two gasoline powered engines each driving a propeller (rotor). The propellers rotated in opposite directions from each other and they rotated on a common axis. The two propellers provided gyroscopic rigidity in space but since the propellers were counter rotating they cancelled out any tendency for precession. The entire structure was a duct and in essence, the whole thing operated like a ducted fan. The basic design of the duct was the downfall of the program. Try to visualize the duct, as a large venturi with the upper end formed like a circular airfoil. The vehicle was caused to move in any given direction by the operator just leaning in that direction. When the vehicle started to move, the duct was tipped from the vertical and as it picked up speed the air flowing over the forward section of the duct was flowing faster than at other circular sections of the duct. Because of the shape of the duct, this increased airflow generated lift and caused the front edge of the duct to raise up to the vertical position. If the operator were still leaning forward the vehicle would return to the position resulting from the leaning of the operator. This resulted in the forward motion being sort of stop and go and stop and go and so on. They were never able to solve the problem so the program was cancelled. It is my understanding that a similar vehicle is being tested that does not have the same characteristics of the Hiller “Flying Manhole Cover.”


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The Cat

[This message has been edited by Lu Zuckerman (edited 09 January 2001).]

[rotorque]

Thanks Lu,

Interesting. There seems to be more interest in the 'mini' flying machines these days, things like the Solotrek etc. It will be fun to see where it all leads.

[helisphere]

I knew an engineer who worked for Hiller and he said that the lift created by the forward side of the duct was not really a problem in fact it contributed to its stablity. It did however limit forward speed to about 25 mph. The reason the project went down the tube was because it could not maintain flight on a single engine. This was not acceptable to the Army and so Hiller built one with three engines. But then it was to heavy to have adequate control from the pilots weight alone, so, they added controls to it. It kept getting bigger and heavier then it needed more power then it was heavier and so on. Finally it was canceled. Apparently the original flew really great except that it would crash if an engine failed.

[Lu Zuckerman]

To: Helisphere

Well, I showed you mine and you showed me yours and guess what? Yours was bigger.

Although your friend told you that the increased lift was not a problem but it limited the forward speed to 25 knots. Did he tell you what happened if the craft exceeded 25 knots? Did he tell you that the increased lift would cause the craft to restore itself to the vertical or near verticcal position and then the pilot would have to lean forward again to cause the Manhole cover to move in the commanded direction? That,s the way I heard it. I was unaware of the engine and weight related problems.

By the way, who do you fly for in the Everett area? I used to spend a lot of time at Geneva Aviation talking to the mechanics about Robinson and Aerospatial helicopters.

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The Cat

[This message has been edited by Lu Zuckerman (edited 13 January 2001).]

[helisphere]

No, he said that it just plain couldn't exceed 25 when leaning all the way forward. By the way his name was John B. Nichols. Who knows, with your experience maybe you ran into him at one time or another. He also worked for Hughes, General Electric (jet engine design), and Boeing. He did most of the work designing the FH-1100 for the army's light helicopter competition. He worked on the XH-17 powerplants and the Hiller tiltwings, and the XROE-1 YROE-1 rotorcycle. Unfortunately Cancer took his life back in 1993.

Actually, I don't work in Everett. I fly down in the Gulf of Mexico. I just live in Wa on my off time. I've seen Geneva Av out there, a friend of mine keeps his plane out there at Paine field.

[This message has been edited by helisphere (edited 14 January 2001).]