# AC 90-66A: Recommended Standard Traffic Patterns and Practices for Aeronautical Operations at Airports without Operating Control Towers - Type: Advisory circular (guidance, not mandatory unless a rule or AD requires it) - Status: Historical - Version in force: [AC 90-66C](https://openairdocs.org/ac/90-66), approved June 6, 2023. This is a historical version - Approved: August 26, 1993 - Last reviewed: July 18, 2024 - Family: AC 90-66 - Cancels: [AC 90-66](https://openairdocs.org/ac/90-66) - Cancelled by: [AC 90-66B](https://openairdocs.org/ac/90-66B) - 14 CFR parts: 1, 91, 93, 97, 103 - 14 CFR sections: [91.113](https://www.ecfr.gov/current/title-14/section-91.113) - Pages: 12 - PDF: https://openairdocs.org/files/sha256/96/3f/963f274d8a1a3bb2c959fcb7e88cc857a4778999d3e3a5a447fa86e8bdfa6efb - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID181263809220240718173758.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ac/90-66A ## Versions - [AC 90-66C](https://openairdocs.org/ac/90-66) (Current), approved Jun 6, 2023, 28 pages - [AC 90-66B CHG 1 Ed Update](https://openairdocs.org/ac/90-66B-CHG-1-Ed-Update) (Historical), approved Jan 21, 2021, 19 pages. Editorial update to AC 90-66B CHG 1. - [AC 90-66B CHG 1](https://openairdocs.org/ac/90-66B-CHG-1) (Historical), approved Feb 25, 2019, 19 pages - [AC 90-66B](https://openairdocs.org/ac/90-66B) (Historical), approved Mar 13, 2018, 18 pages. AC 90-66B cancels both AC 90-66A, Recommended Standard Traffic Patterns and Practices for Aeronautical Operations at Airports without Operating Control Towers, August 26, 1993; and AC 90-42F, Traffic Advisory Practices at Airports without Operating Control Towers, dated May 21, 1990. - [AC 90-66A](https://openairdocs.org/ac/90-66A) (Historical), approved Aug 26, 1993, 12 pages ## Text Each page's text from the PDF; open the PDF at a page with #page=N. This is OCR from the scanned FAA advisory circular. OCR can misread letters and numbers. ### Page 1 (OCR) U.S. Department Advisory of Transportation Federal Aviation Administration Circular Subject: RECOMMENDED STANDARD TRAFFIC **PATTERNS AND PRACTICES FOR** **AERONAUTICAL OPERATIONS AT** **AIRPORTS WITHOUT OPERATING** **CONTROL TOWERS** **1. PURPOSE.** This advisory circular (AC) calls attention to regulatory requirements and recommended procedures for aeronautical operations at airports without operating control towers. It recommends traffic patterns and operational procedures for aircraft, lighter than air, glider, parachute, rotorcraft, and ultralight vehicle operations where such use is not in conflict with existing procedures in effect at those airports. **2. CANCELLATION.** AC 90-66, Recommended Standard Traffic Patterns for Airplane Operations at Uncontrolled Airports, dated February 27, 1975, is cancelled. **3. PRINCIPAL CHANGES.** This AC has been updated to reflect current procedures at airports without operating control towers. Principal changes include: adding on "Other Traffic Pattern" section, amending appendix charts to remain consistent with the Airman's Information Manual (AIM), expanding the Related Reading Material" section from "airplane" to "aeronautical" operations, adding definition and references to Common Traffic Advisory Frequency (CTAF), acknowledging straight-in approaches are not prohibited but may be operationally advantageous, and adding a paragraph on wake turbulence. **4. DEFINITIONS.** a. Airports Without Operating Control Towers. Airports without control towers or an airport with a control tower which is not operating. These airports are commonly referred to as non-towered, uncontrolled, or part-time towered airports. b. Common Traffic Advisory Frequency (CTAF). A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF may be a UNICOM, MULTICOM, Date: 8/26/93 AC No. 90-66A Initiated by: ATP-230 flight service station, or tower frequency and is identified in appropriate aeronautical publications. **5. RELATED READING MATERIAL.** a. Airport/Facility Directory (AFD). b. Airman's Information Manual (AIM). c. Fly Neighborly Guide, Helicopter Association International. d. Aviation USA, Aircraft Owners and Pilots Association (AOPA). e. State aviation publications. f. Various pilot guides. g. Pilot Operations at Nontowered Airports, AOPA Air Safety Foundation pamphlet. h. Guidelines for the Operation of Ultralight Vehicles at Existing Airports, United States Ultralight Association. i. Facts for Pilots, United States Parachute Association. J. The latest addition of the following AC's also contain information applicable to operations at airports without operating control towers: (1) AC 90-23, Aircraft Wake Turbulence. (2) AC 90-42, Traffic Advisory Practices at Airports Without Operating Control Towers. (3) AC 90-48, Pilot's Role in Collision Avoidance. (4) AC 91-32, Safety In and Around Helicopters. (5) AC 103-6, Ultralight Vehicle Operations-Airports, Air Traffic Control, and Weather. (6) AC 105-2, Sport Parachute Jumping. **6. BACKGROUND AND SCOPE.** a. Regulatory provisions relating to traffic patterns are found in Parts 91, 93, and 97 of the Federal Aviation Regulations (FAR). The airport traffic ### Page 2 (OCR) patterns contained in Part 93 relate primarily to tupi tin those airports where there is a need for unique CTAF traffic pattern procedures not provided for in Part the 91. Part 97 addresses instrument approach procedures. om ple- At airports without operating control towers, Part tion of the approach. 91 requires only that pilots of airplanes approaching aircraft to land make all turns to the left unless light nterin 09 signals or visual markings indicate that turns should rection be made to the right. ıld be b. The Federal Aviation Administration (FAA) eratin believes that observance of a standard traffic pattern use and the use of CTAF procedures as detailed in ıld be AC 90-42 will improve the safety and efficiency of aeronautical operations at airports without operating in the traffic pattern. control towers. traffic pattern. and avoid other IC PATTERN. Airport owners and operators, in coordination with the FAA, are responsible for establishing traffic requirement. patterns. However, the FAA encourages airport owners and operators to establish traffic patterns as recommended in this AC. Further, left traffic patterns should be established except where obstacles, terrain, and noise-sensitive areas dictate otherwise. Appendix 1 contains diagrams for recommended standard traffic patterns. a. Prior to entering the traffic pattern at an airport without an operating control tower, aircraft should avoid the flow of traffic until established on the entry leg. For example, wind and landing information. direction indicators can be checked while at an altitude above the traffic pattern. When the proper traffic pattern direction has been determined, the pilot should then proceed to a point well clear of the pattern before descending to the pattern altitude. b. Arriving aircraft should be at the appropriate traffic pattern altitude before entering the traffic pattern. Entry to the downwind leg should be at a 45-degree angle abeam the midpoint of the runway. Page 2 PAR 6 ### Page 3 (OCR) 8/26/93 AC 90-66А a glider has the right-of-way over an airship, airplane, or rotorcraft; and an airship has the right-of-way over an airplane or rotorcraft. **9. OTHER TRAFFIC PATTERNS.** Airport operators routinely establish local procedures for the operation of gliders, parachutists, lighter characteristics. than air aircraft, helicopters, and ultralight vehicles. Appendices 2 and 3 illustrate these operations as they relate to recommended standard traffic patterns. a. Rotorcraft. (1) In the case of a helicopter approaching to land, the pilot must avoid the flow of fixed-wing aircraft and land on a marked helipad or suitable clear area. Pilots should be aware that at some airports, the only suitable landing area is the runway. (2) All pilots should be aware that rotorcraft may fly slower and approach at steeper angles than airplanes. Air taxi is the preferred method for helicopter ground movements which enables the pilot to proceed at an optimum airspeed, minimize downwash effect, and conserve fuel. However, flight over aircraft, vehicles, and personnel should be avoided. (3) In the case of a gyrocopter approaching to land, the pilot should avoid the flow of fixed-wing aircraft until turning final for the active runway. (4) A helicopter operating in the traffic pattern may fly a pattern similar to the airplane pattern at a lower altitude (500 AGL) and closer to the airport. This pattern may be on the opposite side of the runway with turns in the opposite with the direction if local policy permits. (5) Both classes of rotorcraft can be expected to practice power-off landing (autorotation) which will involve a very steep angle of approach and high rate of descent (1,500-2,000 feet/minute). b. Gliders. (1) A glider, including the tow aircraft during towing operations, has the right-of-way over powered aircraft. a turn. (2) If the same runway is used by both airplanes and gliders, the glider traffic pattern will be inside the pattern of engine driven aircraft. If a i Glider knots (230 mph). Operating Area" is established to one side of a powered-aircraft runway, the glider pattern will normally be on the side of the airport closest to the "Glider Operating Area." This will allow gliders to fly the same direction traffic pattern has the as powered aircraft in one wind condition and necessitate a separate opposing direction traffic PAR 8 Page 3 ### Page 4 (OCR) AC 90-66A pattern in the opposite wind condition. (See examples in Appendix 2, Glider Operations). (3) Typically, glider traffic patterns have entry points (initial points) from 600 to 1,000 feet AGL. c. Ultralight Vehicles. (1) In accordance with FAR Part 103, ultralight vehicles are required to yield the right-of-way to all aircraft. (2) Ultralight vehicles should fly the rectangular pattern as described in Appendix 2. Pattern altitude should be 500 feet below and inside the standard pattern altitude established for the airport. An ultralight pattern with its own dedicated landing area will typically have a lower traffic pattern parallel to the standard pattern with turns in the (3) All pilots should be aware that ultralights will fly significantly slower than airplanes. In addition, ultralights may also exhibit very steep takeoff and approach angles. Turns may be executed near the end of the runway in order to clear the area expediently. d. Lighter Than Air Aircraft. (1) A balloon has the right-of-way over any other category of aircraft and does not follow a standard traffic pattern. (2) Due to limited maneuverability, airships do not normally fly a standard traffic pattern. However, if a standard traffic pattern is flown, it will be at an airspeed below most other aircraft. e. Parachute Operations. (1) All activities are normally conducted under a NOTAM noting the location, altitudes, and time or duration of jump operations. The Airport/Facility Directory lists airports where permanent drop zones are located. Page 4 8/26/93 (2) Jumpers normally exit the aircraft either above, or well upwind of, the airport and at altitudes well above traffic pattern altitude. Parachutes are normally deployed between 2,000 feet and 5,000 feet AGL and can be expected to be below 3,000 feet AGL within 2 miles of the airport. (3) Pilots of jump aircraft are required by Part 105 to establish two-way radio communications with the air traffic control facility or Flight Service Station which has jurisdiction over the affected airspace prior to jump operations for the purpose of receiving information in the aircraft about known air traffic in the vicinity. In addition, when jump aircraft are operating at or in the vicinity of an airport, pilots are also encouraged to provide advisory information on the CTAF, i.e., "Chambersburg traffic, jumpers away over Chambersburg. (4) When a drop zone has been established on an airport, parachutists are expected to land within the drop zone. At airports that have not established drop zones, parachutists should avoid landing on runways, taxiways, aprons, and their associated safety areas. Pilots and parachutists should both be aware of the limited flight performance of parachutes and take steps to avoid any potential conflicts between aircraft and parachute operations. (5) Appendix 3 diagrams operations conducted by parachutists. Harold W Becker Harold W. Becker Acting Director, Air Traffic Rules and Procedures Service PAR 9 ### Page 5 (OCR) **APPENDIX 1** **SINGLE RUNWAY AIRPORT OPERATIONS** **APPLICATION OF TRAFFIC PATTERN INDICATORS ENTRY** **DOWNWIND CROSS** **BASE WIND** - SEGMENTED STRAIGHT-IN APPROACH 3- RUNWAY CIRCLE **LANDING** **HAZARD OR DIRECTION** **S POPULATED AREA INDICATOR** **LANDING RUNWAY TRAFFIC PATTERN (OR LANDING STRIP) INDICATORS** **INDICATORS WINDCONE** PARALLEL RUNWAYS LEGEND: **STANDARD LEFT-HAND** TRAFFIC PATTERN (DEPICTED) RUNWAY FINAL STRAIGHT-IN APPROACH VO TRANSGRESSION ZONE 1 SOLENTED FINA **RUNWAY LANDIN** **DIRECTION** **P INDICATOR** **TRAFFIC** **PATTERN** **INDICATORS** **DOWNWIND** **LEGENO STANDARD RIGHT-HAND ENTRY LANDING RUNWA (OR LANDING STRIP)** TRAFFIC PATTERN (DEPICTED) INDICATORS WIND CONE KEY Enter pattern in level flight, abeam the midpoint of the runway, at pattern altitude. (1000' AGL is recommended pattern altitude unless established otherwise. Maintain pattern altitude until abeam approach end of the landing runway, or downwind leg. Complete turn to final at least 1/4 mile from the runway. Continue straight ahead until beyond departure end of runway. 5 If remaining in the traffic pattern, commence turn to crosswind leg beyond the departure end of the runway, within 300 feet of pattern altitude. 6 If departing the traffic pattern, continue straight out, or exit with a 45° left turn beyond the departure end of the runway, after reaching pattern altitude. Do not overshoot final or continue on a track which will penetrate the final approach of the parallel runway. Do not continue on a track which will penetrate the departure path of the parallel runway. **PAGE 1 (AND 2)** ### Page 7 (OCR) **APPENDIX 2** **ULTRALIGHT OPERATIONS** DOWNWIND ULTRALIGHT 500° CROSSWIND **OPERATING ULTRALIGHT** **AREA PATTERN** **ULTRALIGHT OPERATING** **AREA SYMBOL** • RUNWAY **FINAL ULTRALIGHT** **OPERATING AREA** **ULTRALIGHT** **SEPARATE** **OPERATING AREA** **GLIDER OPERATIONS** **GLIDER PATTERN AND POWER PATTERN POWERED PATTERN** **SAME SIDE OF RUNWAY** **GLIDER PATTERN INSIDE TRAFFIC GUDER** PATTERN FOR ENGINE-DRIVEN PATTERN ENTRY GLIDER PATTERN AIRCRAFT (600 - 1,000° AGL) **POWERED RUNWAY - WIND GUIDER** OPERATING AREA 14- - 600 - 1,000° AGL EXIT TOWS TO 2,000 - 3,000 **GLIDER AGL UPWIND** **POWERED** **ENTRY PATTERN ENTRY** POWERED ENTRY POWERED RUNWAY < WIND GLIDER OPERATING AREA * GLIDER PATTERN **GLIDER PATTERN AND POWER PATTERN** OPPOSITE SIDE OF RUNWAY TOWS TO GLIDER PATTERN IS SEPARATE ENTRY 2,000 - 3,000 FT. AGL UPWIND FROM POWERED RUNWAY 600 - 1,000° AGL PAGE 1 (AND 2) ### Page 9 (OCR) **APPENDIX 3** **SIDE VIEW PARACHUTE OPERATIONS 2 MILES 1 MILE** **PROBABLE CHUTE OPENING** EXTREME ZONE EXTREME 3000' 2000' PATTERN A 1250' WINDOW 750° y RUNWAY - 3000' -→ **TOP VIEW** • AIR TRAFFIC PATTERN 1/2 MILE K4,000' - TRUNWAY • 1 MILE 2 MILES **EXTREME** OPENING ZONE "NOTE: THIS DEPICTS AN AIRPORT WHERE NO DROP ZONE HAS BEEN ESTABLISHED.Ị * U.S. GOVERNMENT PRINTING OFFICE : 1997 - 516 - 623 / 83535 PAGE 1 (AND 2) ### Page 12 (OCR) U.S. Department BULK MAIL of Transportation POSTAGE & FEES PAID Administration Federal Aviation FEDERAL AVIATION ADMINISTRATION PERMIT NO. G-44 800 Independence Ave., S.W. Washington, D.C. 20591 **FORWARDING AND RETURN** POSTAGE GUARANTEED Official Business Penalty for Private Use $300 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. 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