Atlas / eCFR / Advisory Circulars
FAA · 2026-04-28
Every FAA Advisory Circular.
ACs are the FAA's non-binding interpretive guidance — how the agency wants you to read the regulation. Each one links forward to the sections it references and back to the parts it applies to, all sourced from the FAA's published index.
Indexed
1,859
Current
779
Cancelled
1,080
Subject series
222
01 / By subject series
Volume per series — each maps to a CFR Part.
-
Series 20
208
ACs
-
Series 120
193
ACs
-
Series 91
91
ACs
-
Series 150/5345
86
ACs
-
Series 90
77
ACs
-
Series 21
76
ACs
-
Series 61
71
ACs
-
Series 00
55
ACs
-
Series 121
42
ACs
-
Series 43
41
ACs
-
Series 23
38
ACs
-
Series 25
38
ACs
-
Series 150/5200
38
ACs
-
Series 150/5340
38
ACs
-
Series 65
37
ACs
-
Series 150/5210
36
ACs
-
Series 150/5220
34
ACs
-
Series 150/5370
31
ACs
02 / Most recent
Last 25 current ACs published.
- 2026-01-30 AC 21-12D Application for U.S. Airworthiness Certificate Part 21 ↗
- 2026-01-23 AC 136-5 Enhanced Flight Following Center (EFFC) for Commercial Air Tour Operators Part 136 ↗
- 2026-01-13 AC 90-23H Aircraft Wake Vortex Encounter Risk Mitigation Part 91 ↗
- 2026-01-13 AC 135-45A Use of Noncertified Weather Observations in Noncontiguous States Part 135 ↗
- 2025-11-14 AC 65-32B Certification of Repairmen (Light-Sport) Part 65 ↗
- 2025-11-14 AC 61-65K Certification: Pilots and Flight and Ground Instructors Part 61 ↗
- 2025-11-14 AC 61-146 Pilot Certification and Operations for Sport Pilots, Flight Instructors with a Sport Pilot Rating, and Simplified Flight Controls Part 61 ↗
- 2025-10-01 AC 187-1U Flight Standards Service Schedule of Charges Outside the United States Part 187 ↗
- 2025-09-29 AC 20-135A Powerplant Installation and Propulsion System Component Fire Protection Test Methods, Standards, and Criteria Part 21, 23+5 ↗
- 2025-09-25 AC 21-32C Control of Prepositioned Products and Articles Shipped Prior to Design Approval Part 21 ↗
- 2025-09-22 AC 43-9D Maintenance Records and FAA Form 8130-3 Return to Service Part 43 ↗
- 2025-09-11 AC 120-53C Flight Standardization Board Evaluations Part 91, 119+4 ↗
- 2025-09-08 AC 33-12 Geometry and Dimensional Considerations for Comparative Test and Analysis for Turbine Engine and Auxiliary Power Unit (APU) Replacement, and Repaired Parts Part 33 ↗
- 2025-09-08 AC 33.15-1A Manufacturing Process of Premium Quality Titanium Alloy Rotating Engine Components Part 33 ↗
- 2025-09-08 AC 20-167B Airworthiness Approval of Enhanced Vision System, Enhanced Flight Vision System, and Combined Vision System Equipment Part 21, 23+5 ↗
- 2025-07-18 AC 21.17-4 Type Certification----Powered-lift Part 21 ↗
- 2025-06-26 AC 150/5220-10F Guide Specification for Aircraft Rescue and Fire Fighting (ARFF) Vehicles Part 139 ↗
- 2025-06-24 AC 91-57D Exception for Limited Recreational Operations of Unmanned Aircraft Part 91 ↗
- 2025-06-18 AC 20-197 Turbine Engine and Airframe Sensor Icing Compliance Part 21, 23+5 ↗
- 2025-06-04 AC 120-105B Foreign Terminal Instrument Procedures (FTIP) Acceptance/Review Part 91, 119+4 ↗
- 2025-05-20 AC 33.17-1B Engine Fire Protection § 33.17 Part 33 ↗
- 2025-05-15 AC 150/5200-34B Construction or Establishment of Landfills Near Public Airports Part 139 ↗
- 2025-04-08 AC 120-126A Guidelines to Establish, Implement, and Maintain a DOT/FAA Drug and Alcohol Testing Program Part 91, 119+4 ↗
- 2025-04-03 AC 91-70D Oceanic and Remote Continental Airspace Operations Part 91 ↗
- 2025-03-11 AC 450.45-2 Compliance when Contracting with a Federal Entity Part 450 ↗
03 / By year
Recent FAA guidance volume.
-
2026
4
-
2025
23
-
2024
60
-
2023
45
-
2022
26
-
2021
26
-
2020
21
-
2019
21
-
2018
34
-
2017
41
-
2016
60
-
2015
47
The bidirectional graph.
Every AC page lists the sections it references — § 25.795 surfaces AC 25.795-1A, 25.795-2A, etc. — and every section page lists the ACs that reference it. The join is sourced from the AC number itself for section-specific ACs (25.795-1 → § 25.795) and from title scanning for ACs that name sections in their subject line.
AC ↔ Part comes from the FAA's subject-series numbering scheme: series 91 covers Part 91, series 25.x targets Part 25, series 120 touches Parts 91/119/121/125/129/135 (cross-cutting operations). Every mapping is deterministic — no ML, no guessing.