[MercianMarcus]

What is meant by the word "bias" when referring to control cables? I'v googled but can only find the usual meaning of the word.

Example of use in a checklist:

Cyclic control check
- blah blah
- Bias of the cables blah blah

[seanjd]

I would interpret this as meaning to ensure any cable operated control systems, operate freely and fully in all directions.
Over time, if cables go over or through guides and pulleys, then both the cables, guides and pulleys could develop flat spots, so at a certain point of travel of the cyclic stick there could be a tendancy for it to stick at that point. It may not be noticeable in flight with the aerodynamic forces, but may be noticeable on the ground.
Also, if there are two cables in the system and one stretched slightly over time and becomes 'slack' the tension will be different to the other cable and may show as a bias in one direction.
That's my understanding of it, but happy to be corrected or if someone can explain it better.

[Morten]

What you are describing would be more likely to be described as 'slack' or 'play', though, no?

Bias is something which has a value when there is no input - I wonder whether they mean that e.g. there should be a force required to start the cyclic moving - in other words, there are positive forces to keep the cyclic centred when you take your hand off it.

I would imagine that this should not be due to stiction, friction or hysteresis, but some spring arrangement.

But I'm really just guessing here.

Ask your mechanic?

Morten

[MercianMarcus]

I found out in type rating ground school that it is related to the balancing of the 2 teleflex cyclic control cables (one being compressed the other stretched). I understand it, but not well enough to explain in detail.

[TrailStar]

Teleflex to the Cyclic?, what Helo is this?

[MercianMarcus]

Rotorway 162f