Ask a CFI: What to Do If You Lose Comms While IFR

Losing communications in IMC is a rare but serious scenario that every instrument pilot should be prepared for. Fortunately, the FAA provides clear guidance in AIM 6-4-1 and §91.185, but interpreting and applying that information on the flight deck—especially under stress—can be confusing. In this installment of Ask a CFI, we’ll break it down and offer some practical tips along the way.

First: Confirm It’s Really Lost Comms

Before diving into the legal guidance, don’t forget some basic troubleshooting:

• Check your radio volume, mic connections, and audio panel selections—a bumped switch is often the culprit.
• Try a backup radio if available.
• Listen on the emergency frequency 121.5 MHz—ATC may be calling you there if they suspect an issue.
• Use your transponder to squawk 7600, which alerts ATC to your situation.
• Try contacting ATC on a nearby frequency—center frequencies often overlap.

What Route Should I Fly? (AIM 6-4-1 Route Guidance)

If you’re convinced your comms are out, the AIM tells us to follow the AVEF mnemonic to determine the correct route:

1. Assigned – the route ATC assigned in your last clearance.
2. Vectored – if being vectored at the time of failure, proceed direct to the fix, route, or airway where you were being vectored to.
3. Expected – the route ATC told you to expect in a further clearance.
4. Filed – your filed flight plan route, if none of the above apply.
5. Always prioritize them in that order.

What Altitude Should I Fly? (AIM 6-4-1 Altitude Guidance)

For altitude, use the MEA mnemonic and fly the highest of the following:

1. Minimum Enroute Altitude (MEA) or other applicable minimum altitude (e.g., MOCA, OROCA).
2. Expected – the altitude ATC told you to expect.
3. Assigned – the last altitude ATC cleared you to.

How to Use the IFR Enroute Chart

Many IFR pilots today are flying GPS-direct and may not be on published airways. This can create confusion about the minimum altitudes to fly during a comms failure. Here’s where the Off Route Obstruction Clearance Altitude (OROCA) becomes important:

• OROCA provides 1,000 feet of obstacle clearance (2,000 in mountainous areas) within a quadrant.
• While not a guaranteed ATC-assigned altitude, OROCA is your safest minimum in a lost comms scenario if you’re off-airway and don’t have a MEA or MOCA to fall back on.
• Always make sure the OROCA you’re referencing covers your actual position—not just your intended route.

Arrival Procedures and Timing

If you’re close to your destination, timing your descent and approach is critical:

• Proceed to the fix from which the approach begins and hold until your EFC time or the ETA filed or amended with ATC.
• Then, commence the approach as close as possible to the expected arrival time.

Tip: If you’re GPS-equipped, and flying direct-to a fix on the approach, ensure that you load the full approach—including the initial and intermediate fixes—to allow for a safe and complete navigation path.

Practical Tips for Prevention

• Always have a backup plan—know your route, alternates, and potential lost comms procedures before entering IMC.
• Keep a cheat sheet or kneeboard card with the AVEF/MEA acronyms.
• Listen to ATIS or other communication frequencies early so you’re aware of expected procedures.
• Consider using datalink (ADS-B or other comms) to stay informed, even when voice fails (even a cell phone if necessary).

Lost comms IFR doesn’t have to be a panic-inducing event. With a firm understanding of the regulations and a plan in place, you’ll be able to continue safely to your destination. Stay calm, fly the airplane, and trust your training.

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Eric Radtke

It was his first airplane trip at age seven that made Eric decide to become a pilot. "While boarding the airplane, a flight attendant noticed my interest in the flight deck and urged me to go talk to the pilot. I give a lot of credit to that pilot for my career choice." Eric earned a bachelor’s degree in finance and went on to an airline career. He learned to fly at Sporty’s as part of the University of Cincinnati’s Professional Pilot Program, an initiative he later directed.Eric now manages Sporty’s media network including FlightTrainingCentral.com. In addition, Eric serves as a Captain in a Cincinnati-based corporate flight department.

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