Definition
An FAA Advisory Circular that provides operational and airworthiness approval guidance for operators conducting Required Navigation Performance (RNP) operations and barometric vertical navigation (baro-VNAV) procedures, including RNP departures, arrivals, approaches, and oceanic/remote routes.
Plain English
It is the FAA's official guidance document telling operators what is needed to gain approval to fly RNP procedures and use barometric vertical navigation.
Context Anchor
Seen in FAA instrument procedure guidance when discussing RNAV and RNP operations, including random RNAV routes and routes that require specific navigation approval.
Derivation
AC' stands for Advisory Circular, the FAA's standard format for non-regulatory guidance. The numbering '90-105' identifies the subject series (90 covers air traffic and general operating rules) and the document number within that series.
Why Pilots Care
It defines the legal and technical requirements a flight must satisfy to use RNP procedures safely and to remain in compliance with ATC clearances.
Intuition Check
Do not read AC 90-105 as a clearance or procedure by itself. It is a guidance document that explains approval standards for certain navigation operations.
Example Sentence 1
The operator referenced AC 90-105 when developing its training program for RNP approach authorization.
Example Sentence 2
Flight planning software confirmed the aircraft met the RNP 1 criteria listed in AC 90-105.