Definition
14 CFR 91.185 is the federal regulation that tells an IFR pilot what to do if two-way radio communication is lost in flight. It specifies the route to fly, the altitude to maintain, and when to begin the approach at the destination, depending on whether the aircraft is in VFR conditions or IFR conditions when the failure occurs.
Plain English
It's the rule that says: if you lose radios while flying on instruments, here's exactly what route to fly, what altitude to hold, and when to start your approach.
Context Anchor
Seen in instrument flying training, lost-radio procedures, and discussions of what to do after a communication failure on an instrument flight.
Derivation
The number comes from Title 14 of the Code of Federal Regulations, Part 91, section 185. Part 91 contains general operating rules for pilots, and section 185 is the specific rule for instrument flights after radio communication is lost.
Why Pilots Care
Following these steps keeps your flight path predictable to ATC and other aircraft, reducing collision risk and maintaining legal compliance.
Intuition Check
Do not read — 91.185 as a radio frequency, altitude, or procedure name. Here it is a regulation citation: the rule number for lost communication during an instrument flight.
Example Sentence 1
After losing both radios in the clouds, the pilot followed 91.185 and continued on the last assigned route at the highest of the assigned, minimum, or expected altitudes.
Example Sentence 2
The crew reviewed 91.185 procedures before departure in case radio failure occurred in IMC.