Two-way communication failure is consistently one of the lowest-scoring categories on the INRAT. It's not that the procedure is complicated — it's that most candidates skip it during prep because it feels intimidating, then run into four or five questions on exam day they can't answer with confidence. Don't be that candidate.

Canadian, not FAA: The comm failure procedure in Canada is governed by the Canadian Aviation Regulations (CARs), not the FARs. If you're studying from American sources, you're learning a different procedure. The routing logic and altitude rules differ.

The first steps

When you lose two-way communication in IMC, the first action is to squawk 7600 on your transponder. This alerts ATC that you have a communication failure, even if you can't hear them.

Then attempt to restore communication. Try other frequencies — ARTCC, approach, tower, FSS, guard (121.5 MHz). Try your receiver only — ATC may be transmitting on a frequency you can still receive but not transmit on. If you hear ATC, follow their instructions if they indicate awareness of your situation.

VMC vs IMC: the split

If you're in VMC

Continue VFR and land as soon as practicable. You're not required to continue the IFR flight plan. Get the aircraft on the ground safely. Notify ATC as soon as possible after landing.

If you're in IMC

This is where the exam questions focus. You continue IFR and follow a specific sequence for routing and altitude selection.

IMC routing: the sequence

When deciding where to fly after comm failure in IMC, follow the route in this order of priority:

Route selection — in order

  1. Assigned route: The last route ATC assigned you
  2. Vectored: If you were being vectored, proceed direct to the fix or route you were being vectored toward
  3. Expected: The route ATC told you to expect
  4. Filed: The route in your original IFR flight plan

The mnemonic most instructors use is AVEF — Assigned, Vectored, Expected, Filed. Use the first one that applies.

IMC altitude: which to fly

For altitude after comm failure, fly the highest of:

Flying the highest keeps you clear of terrain and other traffic. This is a common exam question — candidates often try to fly the lowest altitude to save fuel or descend, which is wrong.

The approach and landing

Proceed to the destination. At the destination, hold as specified in your clearance or as published, then begin the approach at the expected approach time (EAT) if one was issued. If no EAT was given, begin the approach at your estimated time of arrival (ETA) as filed.

ATC will be sequencing traffic around your expected arrival. Following your filed ETA keeps you predictable and reduces the risk of conflict.

The exam tests scenarios, not recitation: Questions won't just ask you to list the steps. They'll give you a specific situation — a partial clearance, a vector, a revised routing — and ask what you do. Work through the AVEF sequence with the scenario details, not from memory alone.

What trips candidates up

The most common errors on comm failure questions involve altitude selection (flying assigned instead of highest) and route priority (forgetting that assigned overrides filed). The second most common error is applying VMC procedures to an IMC scenario or vice versa — read the question carefully for the weather conditions.

This is one of the 13 INRAT categories where reading the TP 691E once isn't enough. Run practice questions on comm failure specifically until the AVEF sequence and altitude logic is automatic.

Practice comm failure scenarios

INRAT practice questions across all 13 categories with AI explanations. Know the procedure cold before exam day.

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Ash H
Flight Instructor  ·  Transport Canada

Ash H has been a flight instructor for 12 years — New Brunswick, Toronto, Collingwood — and has helped hundreds of students prepare for Transport Canada exams. He built IFRTEST.ca because most IFR prep online is written for the FAA, not for this exam.

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