Definition
A text-based communications system, originally using electromechanical machines, that transmits typed messages over telecommunication circuits. In aviation, TTY refers to the teletype format and circuits historically used to distribute weather reports, NOTAMs, flight plans, and other operational data between aviation facilities.
Plain English
A way of sending typed messages from one place to another over a wire. In aviation, it’s the older system used to share things like weather reports and NOTAMs in plain text between airports and flight service offices.
Context Anchor
Seen in FAA acronym, abbreviation, and notice-contraction references, especially when reading older aviation communication terms.
Derivation
From 'teletypewriter' — a machine that types at a distance ('tele-' meaning far, from Greek). The shorthand TTY stuck even after the original mechanical machines were replaced by digital systems.
Why Pilots Care
The blocky, all-caps, abbreviated style of METARs, TAFs, and NOTAMs comes directly from TTY-era constraints. Knowing this helps pilots read those messages without expecting full sentences or modern formatting.
Intuition Check
Do not assume TTY means a modern text message or phone app. In this FAA context, it means teletype: a system for sending typed text over a communication line.
Example Sentence 1
The terminal forecast arrived in TTY format, so the briefer read it off in clipped, all-caps shorthand.
Example Sentence 2
Older NOTAM systems relied on TTY to deliver updates to stations.