Radio failure: what to squawk, how long to hold, when to land
A radio failure is one of the few exam topics where the order of the steps matters as much as the numbers. The procedure is short, and it splits first on one question: are you in visual meteorological conditions or not? This is the sequence, with the numbers that are asked.
Step 1: squawk 7600
Select 7600 on the transponder. It tells ATC that you have lost communications and that they should expect the procedure below. Do not confuse it with 7500 (unlawful interference) or 7700 (emergency).
Step 2: VMC or IMC?
| Situation | What you do |
|---|---|
| VMC | Continue in VMC, land at the nearest suitable aerodrome and report your arrival to ATC. |
| IMC, procedural airspace | Keep the last assigned speed and level (or the minimum flight altitude if that is higher) for 20 minutes after you fail to report over a compulsory reporting point. |
| IMC, surveillance airspace | Keep the last assigned speed and level (or the minimum flight altitude if higher) for 7 minutes, counted from the latest of: reaching that level, setting 7600, or missing a compulsory report. |
Step 3: then fly the flight plan
- Adjust level and speed in accordance with the filed flight plan.
- If you were being vectored, rejoin the flight-plan route no later than the next significant point.
- Start the descent from the navigation aid serving the destination at the last acknowledged expected approach time (EAT). If no EAT was received, use the ETA from the flight plan.
- Fly a normal instrument approach and land, if possible, within 30 minutes after the ETA or the last acknowledged EAT.
Transmitting blind
If you cannot establish contact, keep calling. Start each message with TRANSMITTING BLIND and send it twice. If only your receiver has failed, say TRANSMITTING BLIND DUE TO RECEIVER FAILURE, so that everyone listening knows you can transmit but not hear, and does not wait for a reply.
Where students lose marks
- 20 or 7? Twenty minutes is the procedural airspace figure, seven minutes is with surveillance. A way to remember it: with radar you are seen, so the wait is shorter.
- VMC means land, not continue to destination. The aim is the nearest suitable aerodrome, then a report to ATC.
- Level means the higher of the last assigned level and the minimum flight altitude. The words in brackets are part of the answer.
- Landing time is counted from the ETA or the last acknowledged EAT, not from the moment the radio failed.
Before you get there
Most real radio failures are a loose plug, the wrong frequency or a selector in the wrong position. Check the volume, the headset connectors, the frequency and the audio panel before you start the procedure, and try the other radio if you have one.
This is a study aid, not the regulation. The reference is SERA.14083 and your State’s AIP; local procedures can differ in detail.
Quick answers
What do you squawk when the radio fails?
7600. The other emergency codes are 7500 for unlawful interference and 7700 for an emergency.
What do you do if the radio fails in VMC?
Continue in VMC, land at the nearest suitable aerodrome and report your arrival to ATC.
How long do you keep the last speed and level in IMC?
In procedural airspace, 20 minutes after missing a compulsory position report. Where surveillance is used, 7 minutes. After that, fly the filed flight plan.
What do you say when you cannot hear replies?
Start with TRANSMITTING BLIND and send the message twice. If only your receiver has failed, say TRANSMITTING BLIND DUE TO RECEIVER FAILURE.
Make it stick
Fly the Radio Failure drill: every item is a streak you have to land.