Control Surfaces 2

I thought I'd make this two posts, because combined they're a bit too long, and it's another excuse to up my post count.

There are a few other control surfaces that I didn't cover before. Here's what they are, what they do, and how they work:

Flaps

If you've been on holiday to a foreign country within the past 30 years, chances are you've flown. You may have noticed that before take off something weird's happening to the wings. These are the flaps going down. Remember my little lesson on lift? Well, extending the distance that the air has to go over the top speeds it up, and in return you get more lift.

Whilst taking off and landing you want as much lift as possible. The former to get airborne as quickly and easily as possible, and the former to be able to come in to a landing safely at a low speed. You don't really need the flaps whilst airborne because you need just enough lift to get you airborne, not to go higher. This would be a waste of energy as you'd have to have the nose facing down in order to stop going up in order to maintain your cruising altitude, and less energy would be put into making you go forwards so much as 'downwards'.

Illustration depicting various flap types.

Slats and Slots

These funky things on the wing's leading edge are like little spacers that can be pushed forward in order to make the distance that air has to cover in order to go over the wing much larger. Once again; faster air, more lift. These are used at low speed for additional lift at takeoff, for the most part. They allow air to go through them from under the wing too, providing additional lift. The slat is the physical beam itself that extends from the wing's leading edge. The slot is the space it creates where it used to be, which air from underneath the wing is guided in to in order to have larger quantities of faster moving air on top of the wing to generate more lift.

Slats and Slots at work.

Trim Tabs

Trim tabs are like minor versions of all the previously mentioned control surfaces, with the exceptions of slats and slots. Trim tabs are small control surfaces that are usually at the very tip of the other control surfaces. their position is generally set pre-flight or during flight to counter any small instabilities of the aircraft. If you find that your aircraft yaws to port with no input from you then you'd set the rudder trim to starboard a bit to counteract this action, rather than holding the rudder pedals yourself. This way the aircraft can maintain full manoeuvrability, even if something is causing small changes of course.

Illustration depicting the position of trim tabs. Note that flap trim tabs are omitted.