Thursday, May 19, 2005

Sticks

Q: What's brown and sticky?
A: A stick.

That one has made me laugh since grade two. Apparently it was the most submitted joke to a "funniest joke on the internet" competition, but no one on the committee voted it to win. I guess there were no grade two kids on the committee.

Airplanes have three axes of control: pitch, tipping nose up and nose down, like the movement a rocking chair makes; roll, tipping from side to side like a cyclist leaning into a corner; and yaw, pivoting from side to side, like you can on a piano stool. There are two different types of cockpit controls to manage the movement.

The most common type is the yoke, a steering-wheel like arrangement which produces roll when turned to the side like a steering wheel and pitch when pulled or pushed away from or towards the dashboard. Some airplanes have a control stick instead of a yoke. The stick ranges in appearance from ski pole to video game joystick, but in each case you pull it straight back and forth along the nose-tail line of the airplane to control pitch and waggle it back and forth perpendicular to that line to control roll. If you pull and turn the yoke or move the stick diagonally, you control two axes of movement at once, even if you didn't intend to. Yaw is almost always controlled by pedals on the floor.

The airplanes I trained in had control yokes, and so have all the ones I have flown for work. There are two types of airplanes that have sticks: small, old fashioned recreational airplanes and the most modern airliners. So some airline pilots learned with a stick, progressed to airplanes with yokes and then back to sticks. The cited reasons for the airliner sidestick include freeing up space in the cockpit, and ease of computer control (it truly is a computer joystick), but I wonder how much influence the fact that todays senior airline pilots mostly learned to fly in the J3 Piper Cub had on the argument for the stick.

I have flown a few different airplanes equipped with control sticks (even a modern airliner in a full motion simulator). My first time was in an old cloth-covered airplane with neither differential ailerons nor a turn coordinator. After a few minutes of battling it, I commented that I was overcontrolling because it was difficult to tell when the stick was centred. My instructor replied, "If you were a guy you'd know when the stick was in the middle." I'm not sure whether that was supposed to refer to the presence of a stick-sensitive area of the male anatomy, or a reference to tha amount of time lonely male pilots spend manipulating that centrally located anatomical part. In any event, I wasn't overwhelmed by penis envy, and soon I managed to keep the wings level, stick or none.

4 comments:

Anonymous said...

Dont envy penises. It aint all its made out to be. And yet possession of one seems to be the key to ruling the world.
And
" Brown, sticky and FLOATS". That makes it better.

Anonymous said...

The new composite light aircraft use control sticks as well: Cirrus, Lancair, and Diamond all have them, I think.

Unknown said...

My favourite joke is similar:

What's brown and taps on your window?
Poo on stilts.

Well, there's a stick or two in there somewhere. :)

Aviatrix said...

Good point David. Not only small old recreational, but small, shiny, new-airplane-smell-new recreational planes, too.

And anoynmous, I had that type of aeroplane in mind when I worded the sentence "Yaw is almost always controlled by pedals on the floor." I was also thinking of airplanes adapted for hand controls by pilots who don't have use of their legs.