Glossary

Aileron

A hinged movable surface used for roll control on an airplane.  Found near the tips of the wing.

Airfoil

The shape that a wing has when you look at it from the end.  There are many kinds of airfoils, from very simple flat plates, like our gliders, to graceful teardrop curves to sharp edged rocket fins.

Angle of Attack

The difference between the direction the airplane is pointing and the direction it is going.  The angle of attack is what flight is all about.  At a large angle of attack, an airplane can fly more slowly.  Too large an angle of attack, and the wings stall, or lose lift.  This can happen no matter which way the plane is pointing, because it also matters which way the plane is going. 

Attitude

The attitude of an airplane is which side up it is.  It consists of three parts: Pitch, Yaw, and Roll.

Canard

A small wing in front of the large wing on an airplane.  Sometimes called a stabilizer - but here's the secret - in this case the wing is really the stabilizer.  Canards usually have a movable part for control, called the elevator.  The word "Canard" comes from the French word for "duck".  Perhaps the wing in the back looks like a long-necked duck in flight.

Center of Gravity

This is the place where something balances.  It exists even if there is no gravity - in fact, its real name is "Center of Mass", but for practical purposes they are the same thing. 

Elevator

A hinged, movable surface used for pitch control on an airplane.  Usually found on the stabilizer at the the tail of the airplane, but may also be on the canard, or on a flying wing it may be on the wing itself.

Fin

On an airplane, the fin is in the back.  Sometimes called the 'rudder', the rudder is actually the movable part attached to the fin.

Pitch

The angle the fuselage makes to the ground.  When the nose is pointed up, it is said to be pitched up.  Not to be confused with Angle of Attack

Roll

The angle the wings make to the ground.  When the wings are level, the roll is zero.

Rudder

A hinged, movable surface used for yaw control on an airplane.  Found on the vertical fin.

Stabilizer

A small wing behind the large wing on an airplane.  Wings don't like to fly on their own and must either be shaped carefully or be given help.  A very simple stabilizer is the feathers on an arrow. 
Stabilizers usually have a movable part for control, called the elevator.

Stall

A stall occurs when a lifting surface (wing, fin, stabilizer, canard) has too large an angle of attack.  The air can't follow the shape of the wing anymore, so the lift is interrupted.

Yaw

Motion of the airplane's nose left or right.