Ya

YAG

A widely used solid-state crystal which is composed of yttrium and aluminium oxides which is doped with a small amount of the rare-earth neodymium.

Yagi Antenna

A directional antenna consisting of a rod pointed in the direction of the transmission/reception and several cross bars.

Yard

The yard was a unit of length of the British system of units.

Yaw

The rotation of a body about a vertical axis.

Yawing Moment

A moment that tends to rotate an aircraft about a vertical axis.

y axis

The vertical axis in the plane.