Pilots' Role in Collision Avoidance
Alerts all pilots to the potential hazards of midair collision and near midair collision, and to emphasize those basic problem areas related to the human causal factors where improvements in pilot education, operating practices, procedures, and improved scanning techniques are needed to reduce midair conflicts.
Approval of Area Navigation Systems for use in the U.S. National Airspace System
Provides guidelines for implementation of two-dimensional area navigation (2D RNAV) within the U.S. National Airspace System (NAS). Provides for both VOR/DME dependent systems and self-contained systems such as Inertial Navigation Systems (INS).
AC 20-138C - Airworthiness Approval of Positioning and Navigation Systems supersedes the airworthiness considerations in AC 90-45A, Approval of Area Navigation Systems for use in the U.S. National Airspace System. Equipment previously approved per the airworthiness guidance in AC 90-45A is still valid for the operations and conditions stated in their approvals.
Traffic Advisory Practices at Airports without Operating Control Towers
Contains good operating practices and procedures for use when approaching or departing airports without an operating control tower and airports that have control towers operating part time. Includes changes in radio frequencies and phraseology.
Accidents Resulting from Wheelbarrowing in Tricycle Gear Equipped Aircraft
Explains “wheel barrowing”, the circumstances under which it is likely to occur, and recommended corrective action.
Aircraft Wake Turbulence
This advisory circular (AC) presents basic information on wake vortex behavior, alerts pilots to the hazards of aircraft wake turbulence, and recommends operational procedures to avoid wake turbulence encounters.