Establishment of United States Area Navigation Route T-581 in the Vicinity of Missoula, Montana

What it does

This action establishes United States Area Navigation (RNAV) Route T-581 in the vicinity of Missoula, Montana. The FAA is taking this action to increase navigational flexibility and safety margins for the users and to expand Air Traffic Control operational capabilities.

The Federal Aviation Administration's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 14 of the Code of Federal Regulations:

14 CFR 71

Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).

Compared with

The Federal Aviation Administration has published 482 final rules in 2026 so far, compared with 518 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

Before this

418 earlier Federal Register documents under regulation identifier 2120-AA66 since Jan. 1, 2025.

• Aug. 3, 2026 Final rule. Amendment of Very High Frequency Omnidirectional Range Federal Airways V-108 in the Vicinity of Concord, California
• Aug. 3, 2026 Proposed rule, withdrawal. Amendment of Class D and Class E Airspace; Morgantown, WV: Withdrawal
• July 31, 2026 Final rule. Amendment of United States Area Navigation Routes (RNAV) T-285 and T-286 in the Vicinity of Thedford, NE
• July 31, 2026 Notice of proposed rulemaking (NPRM). Amendment of Jet Route J-24 and Very High Frequency Omnidirectional Range Federal Airways V-244, V-508 and Revocation of Very High Frequency Omnidirectional Range Federal Airway V-255 in the Vicinity of Hays, Kansas.
• July 31, 2026 Final rule. Amendment of United States Area Navigation Route T-388 in the Vicinity of Kodiak, Alaska
• July 31, 2026 Final rule. Amendment of Class D Airspace and Class E Airspace Over Groton, CT
• July 31, 2026 Final rule. Establishment of Prohibited Area P-75; New York, NY
• July 31, 2026 Final rule. Amendment of Class B Airspace; New York, NY

Since then:

• Aug. 4, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class C Airspace and Removal of Class D Airspace; Wilmington International Airport, NC
• Aug. 5, 2026 Final rule. Amendment of United States Area Navigation Route Q-10 and Revocation of Alaska Area Navigation Routes J-804R and J-889R in Alaska
• Aug. 6, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class D and Class E Airspace; Morgantown, WV
• Aug. 7, 2026 Final rule. Amendment of Class D and Class E Airspace; Chicago/Rockford, IL
• Aug. 7, 2026 Final rule. Revocation of Class E Airspace; Lake Geneva, WI
• Aug. 10, 2026 Final rule. Amendment of United States Area Navigation Route T-373 in the Vicinity of King Salmon, Alaska
• Aug. 10, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace; Havana, IL
• Aug. 10, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace; Coleman, TX
• Aug. 11, 2026 Final rule. Amendment of Class D and Class E Airspace and Revocation of Class E Airspace; Muncie and Alexandria, IN
• Aug. 11, 2026 Final rule. Amendment of Class E Airspace; Bedford, IN
• Aug. 11, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class D Airspace and Class E Airspace Over Tri-Cities, TN
• Aug. 11, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace; Canton, IL
• Aug. 12, 2026 Final rule. Amendment of Class E Airspace Over Staunton, VA
• Aug. 13, 2026 Notice of proposed rulemaking (NPRM); correction; extension of comment period. Establishment of Class E Airspace; Havana, IL
• Aug. 17, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace; DeKalb, IL
• Aug. 17, 2026 Notice of proposed rulemaking (NPRM). Revocation of Class E Airspace; Santa Elena, TX
• Aug. 18, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace; Trading Bay Production Airport, Trading Bay, AK
• Aug. 25, 2026 Final rule. Amendment of Restricted Areas R-2505, R-2524, R-2508, and R-2515 in California
• Aug. 31, 2026 Final rule. Airspace Designations; Incorporation by Reference
• Sept. 1, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class D Airspace and Class E Airspace Over New Haven, CT
• Sept. 4, 2026 Final rule. Revocation of Class E Airspace; Point Pleasant, WV
• Sept. 4, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace Over Hardy, VA
• Sept. 4, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace Over Lexington, VA
• Sept. 10, 2026 Final rule. Amendment of Class D and Class E Airspace and Establishment of Class E Airspace; Clovis, NM, and Portales, NM
• Sept. 15, 2026 Notice of proposed rulemaking (NPRM). Modification of Class D and Class E Airspace Areas; Roberts Field/Redmond Municipal Airport, Redmond, OR
• Sept. 15, 2026 Notice of proposed rulemaking (NPRM). Establishment of United States Area Navigation Route T-337 and Amendment of Very High Frequency Omnidirectional Range Federal Airways V-101 and V-484 Near Twin Falls, ID
• Sept. 15, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class E Airspace Over Pittsfield, ME
• Sept. 15, 2026 Final rule. Amendment of Class D and Class E Airspace Over Hyannis, MA
• Sept. 18, 2026 Final rule. Amendment of Class E Airspace; Alma, MI
• Sept. 18, 2026 Final rule; correction. Establishment of United States Area Navigation Route T-581 in the Vicinity of Missoula, Montana
• Sept. 22, 2026 Final rule. Establishment of Class E Airspace; Ottawa, IL
• Sept. 25, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class E Airspace; Del Rio, TX
• Sept. 28, 2026 Supplemental notice of proposed rulemaking (SNPRM). Establishment, Modification, and Revocation of Class E Airspace; Alaska, AK
• Oct. 2, 2026 Notice of proposed rulemaking (NPRM). Amendment of Class D and E Airspace, Revocation of Class E Airspace; Montgomery, AL
• Oct. 5, 2026 Notice of proposed rulemaking (NPRM). Amendment of Domestic Very High Frequency Omnidirectional Range (VOR) Federal Airways V-16, V-184, and Revocation of V-284 and V-577; Eastern United States
• Oct. 6, 2026 Notice of proposed rulemaking (NPRM). Modification of Class E Airspace; Gunnison-Crested Butte Regional Airport, Gunnison, CO
• Oct. 6, 2026 Final rule. Establishment of Class E Airspace; Peoria, IL
• Oct. 13, 2026 Final rule. Amendment of Jet Routes J-83 and J-85, and Very High Frequency Omnidirectional Range (VOR) Federal Airways V-415 and V-605; Eastern United States
• Oct. 13, 2026 Final rule. Amendment of United States Area Navigation (RNAV) Route T-437; Eastern United States
• Oct. 14, 2026 Final rule. Amendment of Boundaries for Restricted Areas R-5301, R-5302B, and R-5302C; NC
• Oct. 14, 2026 Final rule. Amendment of Domestic Very High Frequency Omnidirectional Range (VOR) Federal Airways V-16, V-35, V-37, V-53, V-133, V-136, V-143, V-259, V-310, V-364, V-409, V-415, V-454, and V-605; Eastern United States
• Oct. 16, 2026 Final rule. Establishment of Class E Airspace; Coleman, TX
• Oct. 16, 2026 Final rule. Establishment of Restricted Areas R-5306G and R-5306H and Amendment of Restricted Areas R-5306C and R-5306E; Cherry Point, NC
• Oct. 16, 2026 Final rule. Establishment of United States Area Navigation Route T-550 and Revocation of Very High Frequency Omnidirectional Range Federal Airway V-320
• Oct. 20, 2026 Final rule, administrative correction. Airspace Designations; Incorporation by Reference Amendment of FAA Order JO 7400.11M
• Oct. 22, 2026 Final rule. Establishment of Class E Airspace; DeKalb, IL
• Oct. 22, 2026 Final rule. Revocation of Class E Airspace; Santa Elena, TX
• Oct. 22, 2026 Final rule. Establishment of Class E Airspace; Havana, IL
• Oct. 26, 2026 Final rule. Establishment of Class E Airspace; Canton, IL
• Oct. 28, 2026 Final rule. Modification of Class E Airspace, Samaritan North Lincoln Hospital Heliport, Lincoln City, OR
• Oct. 28, 2026 Final rule; correction. Establishment of Class E Airspace; DeKalb, IL; Correction
• Oct. 28, 2026 Final rule; correction. Establishment of Class E Airspace; Ottawa, IL; Correction
• Oct. 29, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class D Airspace; Winter Haven, FL
• Oct. 30, 2026 Final rule. Amendment of Class D and Establishment of Class E Airspace; Chandler and Phoenix, AZ
• Nov. 4, 2026 Notice of proposed rulemaking (NPRM). Amendment of Domestic Very High Frequency Omnidirectional Range (VOR) Federal Airways V-44, V-170, and V-312; Eastern United States
• Nov. 4, 2026 Final rule; correction. Amendment of Domestic Very High Frequency Omnidirectional Range (VOR) Federal Airways V-16, V-35, V-37, V-53, V-133, V-136, V-143, V-259, V-310, V-364, V-409, V-415, V-454, and V-605; Eastern United States
• Nov. 5, 2026 Final rule. Modification of Class D and Class E Airspace Areas; Roberts Field/Redmond Municipal Airport, Redmond, OR
• Nov. 6, 2026 Notice of proposed rulemaking (NPRM). Establishment of Class E Airspace, Shelter Cove Airport, Shelter Cove, CA
• Nov. 9, 2026 Final rule; correction. Amendment of Class D and Establishment of Class E Airspace; Chandler and Phoenix, AZ

What happens next and when

Effective date 0901 UTC, October 29, 2026. The Director of the Federal Register approves this incorporation by reference action under 1 CFR part 51, subject to the annual revision of FAA Order JO 7400.11 and publication of conforming amendments.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket FAA-2025-3288 on Regulations.gov
• Title 14 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register