IFR Radio Failure Procedures

First actions, before choosing a branch

The first response to silence on the radio is mechanical, not procedural: check the obvious causes. Confirm the volume and headset connections, confirm the selected frequency is correct, and try selecting another frequency for the same unit or a different station that might relay for you. Throughout this, transmit in the blind on the assumption that your transmitter still works even though your receiver does not, since one-way failures are common and a controller hearing a blind call can already start protecting your position.

Squawk 7600 as soon as the failure is recognised. This single action is what lets the controller distinguish a genuine communication failure from an aircraft that has simply gone quiet, and it is the trigger for the controller to begin applying their own side of the same procedure you were taught, clearing other traffic away from where you are expected to be.

The VMC branch: continue visually

If the aircraft is in visual meteorological conditions, or enters them, the procedure is deliberately simple: continue in VMC and land at the nearest suitable aerodrome. There is no level-holding or timing convention to apply here, because a pilot who can see outside is already able to remain clear of terrain and other traffic without ATC's help, and prolonging an instrument-style procedure in good weather would only delay getting the aircraft safely on the ground.

The IMC branch: fly the plan the controller expects

In instrument conditions, the aircraft has no such visual safety net, so the procedure instead makes the aircraft behave exactly as the controller was already told to expect. The pilot maintains the last assigned speed and level, or the applicable minimum flight altitude if that is higher, for a defined period after the failure or after passing the next compulsory reporting point. That period is commonly taught as twenty minutes in a procedural, non-radar environment and seven minutes where the flight is under radar surveillance; treat these as the commonly examined figures, since the exact interval that applies depends on the airspace and rules in force.

After that period, the pilot proceeds according to the filed flight plan, in level and route, to the destination navaid, and then commences the approach at, or as close as possible to, the expected approach time if one has been given, or the estimated time calculated from the flight plan. Every element of this, the level, the route, and the timing, exists to reproduce the picture ATC already holds on paper, so that other traffic can be kept clear of a path the aircraft is still flying even though it cannot be heard.