NORDO Tower Procedures

AIM ¶ 4-2-13 NORDO Tower Procedures

AIM 4-2-13 explains how to communicate with a control tower when your transmitter, receiver, or both are inoperative. Light signals and acknowledgments.

In Plain English

AIM 4-2-13 covers what to do when arriving at or departing a Class D tower-controlled airport with a radio failure. The AIM is informational guidance; the regulatory backbone is 14 CFR 91.125 and 91.129.

Arriving aircraft:

  • Receiver inoperative: Stay outside or above Class D until you determine traffic flow. Then advise the tower of your type, position, altitude, intentions, and request light signal control. Report position 3–5 miles out, on downwind, and turning base.
  • Transmitter inoperative: Stay clear until you observe the flow, join the pattern, monitor the primary tower frequency, and watch for light signals.
  • Both inop: Stay clear, observe the flow, join the pattern, and maintain visual contact with the tower for light signals.

Acknowledging signals:

  • Day: Rock your wings (airplane) or, if a hovering helicopter, turn toward the tower and flash the landing light.
  • Night: Blink the landing or navigation lights.

Departing aircraft: If radio fails before taxi, try to repair it. If not, phone the tower for authorization to depart NORDO. Acknowledge by moving ailerons/rudder (day) or blinking lights (night). If failure occurs after leaving parking, watch for light signals or monitor tower frequency.

AIM Source Text
FAA AIM ¶ 4-2-13
4-2-13. 4-2-13. Communications with Tower when Aircraft Transmitter or Receiver or Both are Inoperative Arriving Aircraft. Receiver inoperative. If you have reason to believe your receiver is inoperative, remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, advise the tower of your type aircraft, position, altitude, intention to land, and request that you be controlled with light signals. REFERENCE- AIM, Para 4-3-13 , Traffic Control Light Signals. When you are approximately 3 to 5 miles from the airport, advise the tower of your position and join the airport traffic pattern. From this point on, watch the tower for light signals. Thereafter, if a complete pattern is made, transmit your position downwind and/or turning base leg. Transmitter inoperative. Remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, join the airport traffic pattern. Monitor the primary local control frequency as depicted on Sectional Charts for landing or traffic information, and look for a light signal which may be addressed to your aircraft. During hours of daylight, acknowledge tower transmissions or light signals by rocking your wings. At night, acknowledge by blinking the landing or navigation lights. To acknowledge tower transmissions during daylight hours, hovering helicopters will turn in the direction of the controlling facility and flash the landing light. While in flight, helicopters should show their acknowledgement of receiving a transmission by making shallow banks in opposite directions. At night, helicopters will acknowledge receipt of transmissions by flashing either the landing or the search light. Transmitter and receiver inoperative. Remain outside or above the Class D surface area until the direction and flow of traffic has been determined; then, join the airport traffic pattern and maintain visual contact with the tower to receive light signals. Acknowledge light signals as noted above. Departing Aircraft. If you experience radio failure prior to leaving the parking area, make every effort to have the equipment repaired. If you are unable to have the malfunction repaired, call the tower by telephone and request authorization to depart without two‐way radio communications. If tower authorization is granted, you will be given departure information and requested to monitor the tower frequency or watch for light signals as appropriate. During daylight hours, acknowledge tower transmissions or light signals by moving the ailerons or rudder. At night, acknowledge by blinking the landing or navigation lights. If radio malfunction occurs after departing the parking area, watch the tower for light signals or monitor tower frequency. REFERENCE- 14 CFR Section 91.125 and 14 CFR Section 91.129.
Oral Exam Questions a DPE Might Ask
Q1If your receiver fails while inbound to a Class D airport, what does the AIM recommend you do?
Per AIM 4-2-13, remain outside or above the Class D surface area until you determine traffic flow, then advise the tower of your type aircraft, position, altitude, and intention to land, and request to be controlled by light signals. At 3–5 miles out, report position and join the pattern, watching the tower for signals and reporting downwind and base.
Q2How do you acknowledge tower transmissions or light signals during the day versus at night with a transmitter failure?
Per AIM 4-2-13, in daylight rock your wings (airplanes) or, for hovering helicopters, turn toward the tower and flash the landing light; in-flight helicopters make shallow banks in opposite directions. At night, blink the landing or navigation lights (or for helicopters, the landing or search light).
Q3What does the AIM say to do if you have a radio failure before leaving the parking area at a towered airport?
Per AIM 4-2-13, make every effort to have the equipment repaired. If unable, call the tower by telephone and request authorization to depart without two-way radio communications. If granted, the tower will issue departure information and instruct you to monitor the frequency or watch for light signals. This procedure ties back to 14 CFR 91.125 and 91.129.
Related Paragraphs in AIM Chapter 4
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AIM 4-2-13 — NORDO Tower Communications