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 operations are subject to specific procedures for entering controlled airspace, communicating intentions, and being sequenced by ATC using light gun signals or pre-arranged procedures.
Plain English
An aircraft that cannot talk to air traffic control by radio, either because it doesn't have one or because the radio stopped working.
Context Anchor
You may see this term in towered airport operations, lost-radio procedures, and discussions of aircraft entering or operating near controlled airspace.
Derivation
NORDO is a contraction of 'No Radio.' It came into use as shorthand in ATC and pilot communications to quickly flag an aircraft that cannot be reached by voice.
Why Pilots Care
NORDO aircraft follow restricted operating procedures, including remaining in visual meteorological conditions and using specific transponder codes to alert others.
Intuition Check
NORDO does not always mean the aircraft has no radio installed. It can also mean the radio has failed or radio contact has been lost.
Example Sentence 1
After his radio failed on the way home, the pilot squawked 7600 and entered the pattern as a NORDO aircraft, watching the tower for light gun signals.
Example Sentence 2
Controllers cleared the NORDO aircraft through Class B airspace only after confirming visual contact with a chase plane.