IFR lost communications procedures14 CFR 91.185 IFR operations: Two-way radio communications failure
If two-way radio communication fails under IFR and you are in VFR conditions, or reach them, continue under VFR and land as soon as practicable. In IFR conditions the rule tells you which route and altitude to fly and when to leave the clearance limit to begin the approach.
By the ATIS Alerts team · Updated October 15, 2026 · Regulation text current as of October 14, 2026. A study aid based on the official regulation text, not legal advice or an FAA interpretation.
At a glance
- Failure in VFR conditions, or VFR conditions encountered after the failure: continue under VFR and land as soon as practicable (b).
- Route in IFR conditions, in order: the route in the last ATC clearance; if being vectored, direct to the fix, route or airway in the vector clearance; the route ATC advised to expect; then the filed route (c)(1).
- Altitude: the highest of the last assigned altitude, the minimum IFR altitude and the altitude ATC advised to expect, for the route segment being flown (c)(2).
- Clearance limit is an approach fix: begin descent or descent and approach as close as possible to the EFC time, or to the ETA if no EFC was received (c)(3)(i).
- Clearance limit is not an approach fix: leave it at the EFC time, or on arrival if no EFC was received, then proceed to an approach fix and begin descent or approach as close as possible to the ETA (c)(3)(ii).
In plain English
Section 91.185 tells an IFR pilot what to do when two-way radio communication fails, unless ATC has authorized otherwise. The first question is the weather. If the failure happens in VFR conditions, or you encounter VFR conditions after the failure, paragraph (b) says to continue the flight under VFR and land as soon as practicable.
If the failure occurs in IFR conditions, or you cannot comply with (b), paragraph (c) sets the route. Fly the route assigned in the last ATC clearance received. If you were being radar vectored, fly the direct route from the point of radio failure to the fix, route or airway specified in the vector clearance. Without an assigned route, use the route ATC advised you to expect in a further clearance, and without that, the route filed in the flight plan.
Altitude is chosen for each route segment being flown. Fly the highest of three values: the altitude or flight level assigned in the last ATC clearance, the minimum altitude for IFR operations (converted to a minimum flight level where 91.121(c) calls for it), and the altitude or flight level ATC advised you to expect in a further clearance. Because the choice is made segment by segment, the altitude can change along the route, for example where a higher minimum IFR altitude applies.
Paragraph (c)(3) covers leaving the clearance limit. If the clearance limit is a fix from which an approach begins, commence descent or descent and approach as close as possible to the expect-further-clearance time if you received one, or otherwise as close as possible to the estimated time of arrival calculated from the filed or amended (with ATC) estimated time en route. If the clearance limit is not such a fix, leave it at the expect-further-clearance time, or on arrival over it if none was received, proceed to a fix from which an approach begins, and commence descent or descent and approach as close as possible to that estimated time of arrival.
Common mistakes
- Staying on the IFR plan after reaching VFR conditions. Paragraph (b) calls for continuing under VFR and landing as soon as practicable.
- Holding the last assigned altitude for the whole flight. The rule takes the highest of the assigned, minimum IFR and expected altitudes for each route segment (c)(2).
- Skipping the expected route. A route ATC advised you to expect comes before the filed route (c)(1)(iii) and (iv).
- Starting the approach as soon as you reach the approach fix. The rule ties the start of descent or approach to the EFC time, or to the ETA if no EFC was received (c)(3)(i).
The official text
14 CFR 91.185 as published on the eCFR, current as of October 14, 2026.
(a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio communications failure when operating under IFR shall comply with the rules of this section.
(b) VFR conditions. If the failure occurs in VFR conditions, or if VFR conditions are encountered after the failure, each pilot shall continue the flight under VFR and land as soon as practicable.
(c) IFR conditions. If the failure occurs in IFR conditions, or if paragraph (b) of this section cannot be complied with, each pilot shall continue the flight according to the following:
(1) Route. (i) By the route assigned in the last ATC clearance received;
(ii) If being radar vectored, by the direct route from the point of radio failure to the fix, route, or airway specified in the vector clearance;
(iii) In the absence of an assigned route, by the route that ATC has advised may be expected in a further clearance; or
(iv) In the absence of an assigned route or a route that ATC has advised may be expected in a further clearance, by the route filed in the flight plan.
(2) Altitude. At the highest of the following altitudes or flight levels for the route segment being flown:
(i) The altitude or flight level assigned in the last ATC clearance received;
(ii) The minimum altitude (converted, if appropriate, to minimum flight level as prescribed in § 91.121(c)) for IFR operations; or
(iii) The altitude or flight level ATC has advised may be expected in a further clearance.
(3) Leave clearance limit. (i) When the clearance limit is a fix from which an approach begins, commence descent or descent and approach as close as possible to the expect-further-clearance time if one has been received, or if one has not been received, as close as possible to the estimated time of arrival as calculated from the filed or amended (with ATC) estimated time en route.
(ii) If the clearance limit is not a fix from which an approach begins, leave the clearance limit at the expect-further-clearance time if one has been received, or if none has been received, upon arrival over the clearance limit, and proceed to a fix from which an approach begins and commence descent or descent and approach as close as possible to the estimated time of arrival as calculated from the filed or amended (with ATC) estimated time en route.
Test yourself
Practice questions from our free FAA written test prep that cite 14 CFR 91.185.
Instrument Rating
During two-way radio failure IFR, the route to be flown is, in order of priority:
- A. assigned, vectored, expected, then filed (AVEF).
- B. filed first, then assigned.
- C. direct to the destination in all cases.
- D. whatever is most convenient.
Show answer
A. assigned, vectored, expected, then filed (AVEF). 14 CFR 91.185(c)(1) sets route priority as Assigned, then Vectored (to the fix/route it was vectored toward), then Expected, then Filed, remembered as 'AVEF'.
More Instrument Rating practice →ATP Multiengine
In the event of two-way radio communications failure under IFR in VFR conditions, the pilot should:
- A. continue the flight under VFR and land as soon as practicable.
- B. continue on the last assigned route to the destination and fly the approach.
- C. climb to the MEA and hold until the failure is resolved.
- D. squawk 7600 and continue IFR to the filed destination regardless of conditions.
Show answer
A. continue the flight under VFR and land as soon as practicable. 91.185(b) is unconditional: if VFR conditions exist or are encountered after the failure, continue VFR and land as soon as practicable. The route and altitude rules in 91.185(c) apply only when that is not possible.
More ATP Multiengine practice →ATP Single-Engine
Under 14 CFR 91.185, if radio communications fail in IMC, the route to be flown is determined by:
- A. the route assigned, then vectored, then expected, then filed.
- B. the filed route in every case.
- C. direct to the destination airport.
- D. the last route acknowledged by ATC only.
Show answer
A. the route assigned, then vectored, then expected, then filed. AVE-F: Assigned, Vectored, Expected, Filed. The altitude question is answered separately, and it is the HIGHEST of the minimum IFR altitude, the expected altitude, and the assigned altitude for each segment.
More ATP Single-Engine practice →CFII Helicopter
An EFC (expect further clearance) time issued with holding instructions matters most because:
- A. it is when the pilot leaves the hold if two-way communications are lost.
- B. it is when holding fuel must be exhausted.
- C. it sets the maximum holding airspeed.
- D. it tells ATC when the pilot began holding.
Show answer
A. it is when the pilot leaves the hold if two-way communications are lost. With communications lost, the pilot leaves a clearance limit that is not an approach fix at the EFC, or, when the limit is the fix where the approach begins, starts descent and the approach as close as possible to the EFC. With no EFC, the pilot leaves a non-approach clearance limit on arrival and times the approach to the filed or amended ETA. Teach students to write the EFC down and to ask when one is not issued.
More CFII Helicopter practice →
Questions pilots ask
What altitude do I fly after losing communications under IFR?
The highest of the altitude or flight level in the last ATC clearance, the minimum altitude for IFR operations, and the altitude or flight level ATC advised you to expect in a further clearance, for the route segment being flown (91.185(c)(2)).
What route do I fly if my radios fail under IFR?
The route in the last ATC clearance received; if being radar vectored, direct from the point of failure to the fix, route or airway in the vector clearance; without an assigned route, the route ATC advised you to expect; and without that, the route filed in the flight plan (91.185(c)(1)).
What if I lose communications in VFR conditions?
Continue the flight under VFR and land as soon as practicable (91.185(b)). The same applies if you encounter VFR conditions after the failure.
When do I start the approach after lost communications?
If the clearance limit is a fix from which an approach begins, commence descent or descent and approach as close as possible to the EFC time, or to the ETA if no EFC was received (91.185(c)(3)(i)). If it is not, leave the clearance limit at the EFC time or on arrival over it, proceed to an approach fix and commence descent or approach as close as possible to the ETA (c)(3)(ii).