NORDO
Encyclopedia
NORDO, short for "No Radio", is a North America
n aviation
term for aircraft flying without a radio
. The term originates from the 5-character uppercase abbreviated notation "NORDO" displayed on controllers' radar scopes when an aircraft transmits the "radio failure" code on its transponder. An alternate explanation is that "NO RDO" was the standard note made on maintenance and equipment sheets used in military aviation, starting in the 1930s, as a code to identify planes which needed radio repairs or were not equipped with radios.
The term has made its way into standard aviation jargon, used as an adjective or a noun to describe an aircraft without a radio, even among pilots and others who are not air traffic controllers.
While sometimes used to denote small general aviation
aircraft that are not equipped with one, the term is more commonly applied to aircraft that have experienced a radio failure in midair. This may constitute an emergency, as determined by the pilot. Aircraft equipped with a transponder should indicate a NORDO situation by setting the appropriate transponder code: 7600 ("seven-six: hear nix"). NORDO aircraft declaring an emergency are given priority over other aircraft (providing a more serious emergency does not occur on another aircraft).
If the radio failure occurs in visual flight rules
(VFR) conditions in an area where radio communication is required, the pilot is expected to continue under VFR and land when feasible. If flying under instrument flight rules
(IFR) conditions, and VFR conditions exist or are encountered after the failure, the flight should be continued in VFR conditions and the pilot shall land as soon as practicable. If VFR conditions do not exist, the pilot will then continue the route last assigned by ATC. See FAR 91.185.
In much of the United States, airplanes can legally fly with no requirement for radio communication. Areas and airports requiring radio communication are designated on aircraft charts.
Air traffic control may re-establish communications with NORDO aircraft by using emergency frequencies, voice features of NAVAIDs, or aviation light signals
. In the event of one-way communications (i.e. aircraft can receive only), the controller may request the aircraft make identifying turns, flash their navigational lights, transmit codes or IDENT signals on the transponder, rock their wings, etc, to acknowledge clearances or instructions.
Within Class Delta airspace, military aircraft with arrested landing capability desiring arrested landing or crash/rescue assistance should execute a 500 foot AGL low approach with "tailhook" extended and observe tower light signals.
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n aviation
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...
term for aircraft flying without a radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
. The term originates from the 5-character uppercase abbreviated notation "NORDO" displayed on controllers' radar scopes when an aircraft transmits the "radio failure" code on its transponder. An alternate explanation is that "NO RDO" was the standard note made on maintenance and equipment sheets used in military aviation, starting in the 1930s, as a code to identify planes which needed radio repairs or were not equipped with radios.
The term has made its way into standard aviation jargon, used as an adjective or a noun to describe an aircraft without a radio, even among pilots and others who are not air traffic controllers.
While sometimes used to denote small general aviation
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...
aircraft that are not equipped with one, the term is more commonly applied to aircraft that have experienced a radio failure in midair. This may constitute an emergency, as determined by the pilot. Aircraft equipped with a transponder should indicate a NORDO situation by setting the appropriate transponder code: 7600 ("seven-six: hear nix"). NORDO aircraft declaring an emergency are given priority over other aircraft (providing a more serious emergency does not occur on another aircraft).
If the radio failure occurs in visual flight rules
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
(VFR) conditions in an area where radio communication is required, the pilot is expected to continue under VFR and land when feasible. If flying under instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
(IFR) conditions, and VFR conditions exist or are encountered after the failure, the flight should be continued in VFR conditions and the pilot shall land as soon as practicable. If VFR conditions do not exist, the pilot will then continue the route last assigned by ATC. See FAR 91.185.
In much of the United States, airplanes can legally fly with no requirement for radio communication. Areas and airports requiring radio communication are designated on aircraft charts.
Air traffic control may re-establish communications with NORDO aircraft by using emergency frequencies, voice features of NAVAIDs, or aviation light signals
Aviation light signals
In the case of a radio failure or aircraft not equipped with a radio, air traffic control may use a signal lamp to direct the aircraft. The signal lamp has a focused bright beam and is capable of emitting three different colors: red, white and green. These colors may be flashed or steady, and have...
. In the event of one-way communications (i.e. aircraft can receive only), the controller may request the aircraft make identifying turns, flash their navigational lights, transmit codes or IDENT signals on the transponder, rock their wings, etc, to acknowledge clearances or instructions.
Within Class Delta airspace, military aircraft with arrested landing capability desiring arrested landing or crash/rescue assistance should execute a 500 foot AGL low approach with "tailhook" extended and observe tower light signals.