You are flying through the clouds on an IFR flight plan. You hear a constant stream of radio talk coming through your headset and then everything goes silent. You pull out your squelch knob and turn up the volume. Nothing. You press down your mic key and make a call trying to get someone to respond. Nothing. Next, you try switching frequencies to find any type of radio communication. Nothing is coming in and nothing is going out. What should you do? Communicating with Air Traffic Control is important while flying in the clouds under an IFR flight plan. They provide aircraft separation and provide directions on when and where to turn. Title 14 CFR Part 91.185 describes what to do in the event of a two-way radio communications failure.
If you are flying under VFR conditions, you should set your transponder to 7600, continue the flight under VFR and land as soon as practicable, preferably to an airport that does not require two-way radio communication.
If the radio communication failure occurs while in IMC conditions, the pilot must continue flight along the following parameters:
Route: The route that you will take depends on what you have received by ATC before the radio communication failure. It can be remembered by the acronym “AVEF.” In the event of radio communication failure in IFR conditions, you must continue flight according to the following:
1. Assigned: By the route Assigned in the last ATC clearance received.
2. Vectored: If you are being radar Vectored, by the direct route from the point of radio failure to the fix, route, or airway specified in the vector clearance.
3. Expected: In the absence of an assigned route, follow the Expected in a further clearance route.
4. Filed: If none of the previous routes apply, you should fly the route you Filed for your flight plan.
Altitude: The altitude you will fly at can be remembered by the acronym “MEA.” You should fly at the highest of the following altitudes for the route segments being flown:
1. Minimum: The Minimum altitude for IFR operations.
2. Expected: The Altitude Expected in a further clearance.
3. Assigned: The altitude Assigned in the last ATC clearance received.
After you arrive at the clearance limit, you must commence the descent or descent and approach as close as possible to the expect further clearance time if ATC has assigned one to you. If a time has not been provided to you, begin the descent that and approach as close as possible to your estimated time of arrival that you filed in your flight plan.
Other Related Articles:
Pilot’s Guide: Spatial Disorientation
Pilot’s Guide: IFR Clearances
Pilot’s Guide: Briefing Instrument Approaches
Pilot’s Guide: Calculating Pressure and Density Altitudes
Resources: 14 CFR 91.185
Instrument Flying Handbook, 2007, FAA-H-8083-15A