FAR Ninety-One Point One Eighty-Five, the Lost Comms Procedure Every Student Memorizes Wrong, and the Three Steps That Have to Be Automatic Before You Sit Down With the Examiner

Radio failure in flight is a manageable emergency with a clear, procedural response. The most common checkride mistake is confusing the IFR regulation with VFR practice - or knowing the squawk code without knowing what comes next. Three steps must be automatic: confirm the failure, squawk 7600, and fly to a resolution using standard, predictable procedures.

Is FAR 91.185 a VFR or IFR Regulation?

Federal Aviation Regulation 91.185 is an IFR regulation. Its section heading states it plainly: IFR Operations, Two-Way Radio Communications Failure. If you are flying VFR when your radio quits, 91.185 is your guiding framework - but its specific procedural requirements apply to instrument operations, not visual flight.

This distinction is a common oral exam trap. If the examiner asks what 91.185 requires and you start describing VFR procedures, you are mixing frameworks. VFR radio failure guidance is less codified and more principle-based: remain predictable, use every available communication channel, and get on the ground safely.

How Do I Confirm a Radio Failure Before Taking Action?

Approximately half of all in-flight radio failures are not actually radio failures - they are human interface failures. Volume turned down. Headset plug partially unseated. Wrong frequency dialed in. Squelch set too high. Second radio not selected.

Before treating a failure as confirmed, run a quick check: volume up, frequency verified, headset reseated, second radio if installed, handheld if carried. This takes 15–20 seconds and eliminates the most common causes. Squawking an emergency code because a headset jack partially unseated is a preventable situation that leads to uncomfortable conversations with the tower.

Confirm the failure before you treat it as one.

What Are the First Steps When Your Radio Actually Fails?

Step 1: Squawk 7600. This is the international standard transponder code for radio communications failure. It is not the emergency squawk - that is 7700. The moment 7600 appears on a radar screen, qualified controllers will see it and begin adapting: clearing airspace ahead of your position, holding conflicting traffic, and anticipating your intentions based on your last known position and standard procedures. You are still inside the ATC system.

Step 2: Continue flying the airplane. The natural response to a system failure is to fixate on it. In an airplane, that is exactly wrong. Maintain altitude. Maintain airspeed. Troubleshoot second.

Step 3: Decide where you are going and get there predictably. If you are not inside Class Bravo, Charlie, or Delta airspace, the guidance is straightforward: find the nearest suitable airport and land as soon as practicable. VFR pilots are under no obligation to continue to a towered airport without a working radio. An uncontrolled field on a clear day is a completely legitimate resolution.

What Do I Do If I’m Already in the Pattern at a Towered Airport?

If you are already established in the pattern at a towered field when communications fail, you use light gun signals. The tower will direct a focused, high-intensity beam at your aircraft and communicate through color and flash pattern.

There are 12 total light gun combinations, but six apply to airborne aircraft. These are the ones that must be immediate recall before the checkride:

A fast mental framework: green means approved or proceed, red means stop or danger, white means something positional or administrative, alternating is always caution. That is not precise for every signal but gives your brain a sorting system under stress.

The on-ground signals follow a parallel structure. Steady green is cleared for takeoff. Flashing green is cleared to taxi. Steady red is stop. Flashing red on the ground means taxi clear of the runway in use immediately. Flashing white means return to your starting point. Alternating red and green carries the same caution meaning as in the air.

How Do I Acknowledge a Light Gun Signal?

This is the gap found in almost every student debrief on this topic.

When the tower fires a light gun signal, they do not automatically know you received it. They are watching your aircraft for a response. If they see none, they may escalate or assume the signal was missed.

During daylight, you acknowledge by rocking your wings - a deliberate roll left and right, clearly intentional. At night, you acknowledge by flashing your landing light on and off.

This acknowledgment procedure is documented in the Aeronautical Information Manual, Chapter 4, Section 3. It is two sentences. It is also the specific detail that surfaces most often when examiners follow up on the light gun question.

The examiner asks what you do when you receive a steady green on final. The student says land. The examiner asks how you tell the tower you received it. Many students go quiet. Rock the wings. Flash the landing light at night. Know it before walking into the room.

How Does the Full Scenario Play Out?

Returning to the opening scenario: you are on three-mile final, radio confirmed dead, 7600 squawked. Continue the approach. Watch the tower cab for a light signal.

• Receive a steady green: rock your wings to acknowledge, land.
• Receive a steady red on downwind: continue circling in the pattern, wait for another signal.
• Receive a flashing red: go around, climb out, fly clear of the airspace, divert.

After landing, go talk to the tower. The regulations require notifying ATC as soon as practicable following a communications failure. Do not tie down and go home.

The examiner wants to hear that you do not declare a radio failure and do whatever you want. You remain inside the system. You fly standard, predictable procedures. The aircraft that behaves predictably is the aircraft the system can protect.

What Does FAR 91.185 Actually Require for IFR Flights?

For pilots pursuing an instrument rating, understanding the full regulation reinforces why VFR lost comms principles are structured the way they are.

If communications fail in visual meteorological conditions while flying IFR, the regulation says to continue in visual conditions and land as soon as practicable - essentially the same guidance as VFR practice.

If communications fail in instrument meteorological conditions, the procedure becomes specific. For route, the priority order is:

1. The route assigned in the last ATC clearance
2. The route being vectored toward, if on vectors
3. The route ATC stated to expect in a further clearance
4. The route filed in the flight plan

For altitude, fly the highest of: the minimum IFR altitude for the route segment, the altitude assigned in the last clearance, or the altitude told to expect.

Timing and approach guidance in the regulation also specifies when to leave a holding fix and begin an approach based on expected further clearance time. VFR students are not expected to execute this on the private checkride, but knowing the framework reinforces the same underlying principle: be systematic, be predictable, follow the last known plan.

How Can I Practice This Before the Checkride?

The most effective preparation is not ground study - it is a live light gun exercise.

Call your local tower, ask for the operations supervisor, explain that you are a student pilot preparing for a practical test, and ask whether they would coordinate a light gun exercise. Many towers will say yes. You fly a pattern with your radio silent, receive real light gun signals from the cab, and respond.

The first time a light gun signal reaches you from the seat of an airplane, the acknowledgment procedure stops being something to memorize and becomes something you understand. You rock those wings because you genuinely want the tower to know you received the message.

That experience is documented in the AIM, Chapter 4, Section 3, and the radio failure topic is covered in the FAA’s Pilot’s Handbook of Aeronautical Knowledge (communications chapter). Both are free downloads from the FAA.

Key Takeaways

• FAR 91.185 is an IFR regulation. VFR radio failure uses it as a framework, but the specific procedural requirements apply to instrument operations.
• Confirm before you act. About half of apparent radio failures are volume, frequency, or headset connection issues - a 15–20 second check eliminates them.
• Squawk 7600, not 7700. 7600 is radio failure; 7700 is emergency. The difference matters to every controller watching your target.
• Know all six airborne light gun signals cold, with the acknowledgment procedure: rock wings in daylight, flash landing light at night.
• After landing, notify ATC as soon as practicable. The procedure does not end when the wheels touch.