The FAA has issued a fresh Beechcraft King Air 350 airworthiness directive.
The rule covers Textron Aviation Model B300 and B300C aircraft. It responds to a manufacturer revision of inspection intervals for cracks in wing spar and supporting structure components. It requires every affected operator to adopt those revised intervals.
The published action is a final rule with a parallel request for comments. It becomes effective on 10 August 2026. Operators must revise the airworthiness limitations section of the aircraft maintenance manual, or the instructions for continued airworthiness, and update their approved maintenance and inspection programme to match.
The FAA numbered the rule AD 2026-15-05. The Federal Register document number is 2026-15006, published on 24 July 2026, under docket FAA-2026-7223.
The B300 is the type-certificate designation for the Beechcraft King Air 350 twin turboprop, and B300C is the King Air 350C cargo variant. Both are current-production airframes under the King Air 360 marketing name that Textron Aviation adopted in 2020. The type is the largest single-cabin King Air derivative and one of the most common twin-turboprop platforms in owner-operator hands. A large installed fleet operates under Part 91 and Part 135 in North America, Europe and the Middle East. The revised intervals apply to serial-number ranges specified inside the AD text.
Owners and operators should confirm whether their airframe is in scope before the 10 August effective date. The Federal Register document lists the applicable serial numbers and the manufacturer inspection references that operators must incorporate into an existing continuous airworthiness maintenance programme.
Source: FAA final rule AD 2026-15-05, Federal Register document 2026-15006, 24 July 2026.