Bone Question

[whowhenwhy]

Just a quick question - if a fixed wing has got 3 axes (lateral, normal and longtitudinal), what do you call them in a rotary wing, because haven't you got 4? Or am I being thick?

Cheers!:)

[VeeAny]

We still have 3, we just find it easier to rotate about some of them and translate along all of them if we want.

[Whirlygig]

Fixed wing and helicopters also have a fourth dimension (as does everything); it's called time. :}

Cheers

Whirls

[whowhenwhy]

So you can yaw around and move along the normal axis??

[VeeAny]

WhoWhenWhy

Exactly That, the thrust generated by the tail rotor controls yaw (rotation) about that axis, and due to the fact that we can change the magnitude the thrust generated by the main rotor it gives us the ability to move up and down the normal axis.

Tail rotor thrust is controlled by the Yaw Pedals, Main rotor thrust magnitude is controlled by the collective pitch lever and the RPM of the main rotor which is sometimes manually controlled or sometimes mechanically or electrically governed. Although we usually operate most helicopters at constant RPM for the type.

Changing the alignment of that rotor thrust in space is what gives us control over where the aircraft goes.

As opposed to a traditional fixed wing which is usually pushed or pulled by something aligned roughly along the longitudinal axis and which needs to be moving itself to be able to rotate about any of the axes.

GS

[whowhenwhy]

VeeAny - many thanks. I should have just asked that question in the first place because that was the answer that I needed! Whirlygig, if you ever come up with a way of controlling the 4th dimension please let me know - I'd pay a lot!!!:ok:

[MightyGem]

I'd pay a lot!!
Yes me too! It's going far too quick these days. :eek:

[Whirlygig]

Mighty ... you need one of these ...

http://www.daviddarling.info/images/wormhole_graphic.jpg

Never could get my head 'round tensor calculus :\

Cheers

Whirls

[Non-PC Plod]

Whirls,

With all that negative energy available behind the mouth - just wondering what the diagram of my Chief Instructor has to do with the space-time continuum?:E

[Two's in]

Not forgettng that the Normal Axis is also called the Vertical Axis (eaiser to visualize). May be a Naval throwback, but equipment mounted aligned with the Lateral Axis is referred to as "Athwartships" - is that not a great word?