On a Wing and a Tail…plane… and fin. That title didn’t work out so well.

The wings, fin and tailplane are the vital surfaces which keep the aircraft:

• Flying
• Flying straight

Lose anything mid-flight, and things become very bad very quickly. Let’s see why.

Flying Surfaces

Wings: we’ll go into the physics later, but for now, all you need to know is that they provide all the delicious lift needed to make us fly. Lose your wings, lose your lift. And fall.

As for the tail – it’s all about stability. The whole tail section of the aircraft is collectively known as the ’empennage’, which includes the fin (the vertical one) and the tailplane (the horizontal one). In essence, the empennage keeps the aircraft controllable.

The fin and attached rudder serve two different purposes: the fin acts like a weathercock to push the aircraft heading into the local wind direction, and the rudder provides control to make sure the pilot can still control where he or she is going. The rudders on a boat and aircraft have the exact same purpose. The really nifty bit is that as the wind gusts or increases in strength, the weathercocking effect of the fin pushes the aircraft’s nose (the front bit) into the incoming airflow to compensate. Imagine landing with the wind blowing across the runway. The wind is trying to drag you with it, out of line with the runway and into a field of helpless kittens. But wait! Your fin causes you to weathercock into the airflow, allowing you to defy the wind and keeping you moving towards that glorious asphalt. Now you and the kittens are safe. Without a fin, the aircraft would wander about all over the place, and probably crash somewhere, which would make for a rubbish day.

The tailplane, while more complex in its workings, performs a similar function. For reasons I’ll explain later, most aircraft actually need their tails to produce negative lift (i.e. pushing downwards) to keep flying straight. The tailplane provides pitch (facing up or down) stability, and the attached elevators provide control to the pilot. Without a tailplane, most aircraft would plough straight into the ground. Without elevators, the only way to get an aircraft flying straight and level would be to fly at a certain (very fast) speed. Landing at these speeds would be disastrous.

So there you have it. Don’t lose your wings, fin or tailplane, or bad things will happen.

Just a note: we won’t be covering tandem wing or similar configurations. If you don’t know what this means, just ignore this block.