Definition
An aircraft operating without a functioning two-way radio, either because no radio is installed or because the radio has failed in flight. Nordo aircraft must follow specific lost-communication procedures and, in controlled airspace, rely on light-gun signals from the tower for clearances and instructions.
Plain English
An aircraft that cannot talk to air traffic control or other aircraft by radio, either because it has no radio or because the radio has stopped working.
Context Anchor
Used around airports, in traffic discussions, and when planning how an aircraft will communicate if the radio is absent or fails.
Derivation
A pilot-slang contraction of 'no radio' — 'no' plus 'rdo,' the common shorthand for radio. The term grew out of controller and pilot shorthand and is now used informally throughout aviation.
Why Pilots Care
A NORDO aircraft must follow published lost-communications routes, squawk 7600, and comply with light-gun signals at towered airports, directly affecting routing, timing, and landing options.
Intuition Check
Do not read Nordo as a model name or location. It simply means “no radio” or “no usable radio communication.”
Example Sentence 1
After his radio failed on the downwind, he became nordo and watched the tower for a steady green light to clear him to land.
Example Sentence 2
The tower used light signals because the incoming trainer was NORDO.