Definition
Securing an aircraft, balloon, or airship to the ground or to a fixed object by one or more lines or cables to prevent it from drifting or moving away.
Plain English
Tying an aircraft to the ground with ropes or cables so it stays put.
Context Anchor
Pilots most often encounter tethering in balloon and airship operations, ground handling, aircraft storage, and test setups where an aircraft or object must be held safely in place.
Derivation
From the Old Norse 'tjothr', meaning a rope or chain used to tie an animal so it can graze without wandering off. The aviation use carries the same idea — keeping something in place with a line.
Why Pilots Care
Correct tethering prevents wind damage or loss of the aircraft while it is on the ground.
Intuition Check
Tethering does not always mean locking something completely motionless. It means restraining it so any movement stays within a safe, controlled limit.
Example Sentence 1
The hot air balloon was kept on a short tether for the crew demonstration so it could rise only a few feet off the ground.
Example Sentence 2
Strong crosswinds made tethering the airplane essential to keep it from shifting on the ramp.