B167

DESIGN: SynchroLite ~ Control - Flight - Cyclic

Outside Helicopters

Cyclic Controls

Web page by Paul Cantrell

Kaman H-44:

Lateral: Moving the stick sideways caused the corresponding disk to tilt, with the opposite rotor following the movement only partially so its blade wouldn't strike the opposite hub.

UltraSport 

Indian Helicopter

On the Indian helicopter 1" of longitudinal or lateral movement at the top of the 17" high cyclic control stick produces 1 degree of pitch change. Actually the longitudinal change in pitch is 1.0261 degree and the lateral change is 0.9436 degree, for 1" of movement.  

Rotorway Exec 90

When cyclic handle is against the-

- forward stop the swashplate tips 5 º down in front.

- rear stop the swashplate tips 5 º down in rear.

- left stop the swashplate tips 5 º down on the left.

- right stop the swashplate tips 5 º down on the right.

The pitch rod appear to flare out slightly as the move up to the blade pitch link, in other words the cyclic portion of the pitch will be less than +/- 5 degrees. 

 

Re Airplane Cabin Dimensioning:

Sportsplane Book

In the plane view a "box" 10" square is allocated for stick movement. I.e. 5" forward, back or to either side of the mid position. This would mean that in the Indian the maximum cyclic pitch change is about 5 degrees. 

Bell 47

The Bell 47 cyclic stick has approximately 5" of horizontal movement in all four directions from it's mid position. I.e. 10" * 10" box, just like above. It would visually appear that the pitch only changes +7 to -7 degrees for full cyclic lever travel. 

Friction Adjustment:

Robinson

The Robinson R22 has a friction adjustment on the cyclic. Probably all major helicopters do.  

 

Notes:

Posting on rotorcraft forum, Probably related to gyrocopter, but still of value.

Stick travel is measured in inches of hand movement (center of stick grip) as compared to degree of angle of the rotor head. The PRA recommendation is 0.8 inch fore-aft and .072 inch side-side for each angle of rotor head movement. For example, you would move the stick 7.2" back to get 9 degree rear tilt of the rotor head.

Same Page ~ Different Craft:

B293

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Last Revised: February 13, 2005