Definition
Movement of a body in a straight line, in which every point of the body moves in the same direction at the same speed, with no rotation about any axis.
Plain English
The whole object slides along a straight path without spinning or turning. Every part of it moves together in the same direction at the same rate.
Context Anchor
Seen in helicopter and rotorcraft discussions, especially when describing movement out of a hover or movement across the ground.
Derivation
From the Latin 'translatio,' meaning 'a carrying across.' In physics and aviation it kept that simple sense: something is carried from one place to another in a straight line, as opposed to rotating in place.
Why Pilots Care
A helicopter pilot must recognize translation because the aircraft handles differently when it starts moving across the air instead of hovering in one spot.
Grounding Statement
If a helicopter lifts into a hover and then begins moving forward across the ramp, it has entered translation.
Intuition Check
Do not confuse translation with language translation. In this aviation use, translation means physical movement from one place to another.
Example Sentence 1
An aircraft cruising straight and level is in pure translation through the air.
Example Sentence 2
Pure translation along the lateral axis allowed the pilot to reposition the aircraft without changing heading.