Lost Communications Under IFR (91.185)

A two-way radio failure under IFR is one of the few emergencies with a specific regulatory script, 14 CFR 91.185. Knowing it cold means you can keep flying predictably while ATC keeps other traffic clear of you. Squawk 7600 to tell them you have lost communications.

If you are in VMC

If the failure occurs in visual conditions, or you encounter VMC after it occurs, the rule is simple: continue under VFR and land as soon as practicable. Do not press on in the system when you can safely stay visual and get down.

If you are in IMC — the route

When you must continue in instrument conditions, fly the route in this order of preference ("AVEF"):

• A — Assigned: the route ATC last assigned.
• V — Vectored: if being radar-vectored, the direct route from the point of failure to the fix/route specified in the vector.
• E — Expected: the route ATC told you to *expect* in a further clearance.
• F — Filed: the route you filed in your flight plan.

If you are in IMC — the altitude

For each segment, fly the highest of these three ("MEA" as a memory aid):

• M — Minimum: the minimum en-route altitude (MEA) for the segment.
• E — Expected: the altitude ATC told you to expect.
• A — Assigned: the last altitude assigned.

Timing at the destination

Leave the clearance limit to begin the approach as close as possible to your expect-further-clearance (EFC) time, or — if the clearance limit is the fix from which the approach begins and you have no EFC — as close as possible to your flight-plan ETA. Then fly a published approach and land.

Practising the AVEF/MEA logic on the ground makes it automatic when the panel goes quiet. See also radio communications and standard phraseology.

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*Reference and training only — not for navigation or as legal advice. Always consult the current 14 CFR, the AIM, your aircraft’s POH/AFM and a certificated flight instructor.*