Definition
An FAA Advisory Circular that provides guidance, recommended practices, and operational information for the use of Enhanced Flight Vision Systems (EFVS) during instrument approach procedures. It explains how operators may use an EFVS to descend below the published Decision Altitude, Decision Height, or Minimum Descent Altitude when the required visual references are seen on the EFVS display rather than with natural vision.
Plain English
It is an FAA document that tells pilots and operators how to use Enhanced Flight Vision Systems on instrument approaches, including when they can continue an approach using the EFVS image instead of looking out the window.
Context Anchor
Seen in discussions of Enhanced Flight Vision Systems, instrument approach procedures, pilot training, and operator authorization.
Derivation
An 'Advisory Circular' is an FAA publication that advises — it offers guidance and acceptable means of compliance, but is generally not regulatory itself. The number '90-106' identifies the subject series (90 = Air Traffic and General Operating Rules) and the specific circular within that series.
Why Pilots Care
Pilots must follow its requirements to obtain the necessary training, equipment certification, and operational approval before relying on EFVS to fly approaches to lower-than-standard minima.
Intuition Check
Do not read “Advisory Circular” as “a rule by itself.” AC 90-106 is FAA guidance; the regulations still control what is legally required.
Example Sentence 1
Before flying the EFVS approach, the captain reviewed AC 90-106 to confirm the required visual references for descent below DA.
Example Sentence 2
Dispatch confirmed the aircraft met all AC 90-106 requirements before releasing the flight for an EFVS arrival.