FAA orders replacement of radio altimeter cables on Boeing 787 jets

The Federal Aviation Administration will require operators of Boeing 787-8, 787-9 and 787-10 airplanes to replace both radio altimeter coaxial cables under final airworthiness directive AD 2026-22-09, published in the Federal Register on 9 November 2026 and effective 14 December 2026. The rule, issued under Docket No. FAA-2026-1335, Project Identifier AD-2025-00825-T and Amendment 39-23511, addresses low-altitude altimeter failures that the agency says could result in “loss of continued safe flight and landing.” It binds the entire widebody family, not a single operator or configuration.

The directive amends 14 CFR part 39 and follows a notice of proposed rulemaking published on 24 February 2026 (91 FR 8794). It was prompted by reports that the low range radio altimeter (LRRA) system has an increased rate of non-computed data (NCD) outputs at low altitudes during approach and landing, which could cause unreliable altimeter function — a component the FAA describes as necessary for everyday operations.

What the directive requires

The FAA requires replacing the existing left and right BMS13-65 Type 0G LRRA transmit and receive coaxial cables with larger gauge Type 0J coaxial cables, work classified under Air Transport Association of America Code 34, Navigation.

• Material incorporated by reference: Boeing Alert Requirements Bulletin B787-81205-SB340062-00 RB, Issue 001, dated 23 December 2024, approved by the Director of the Federal Register as of 14 December 2026.
• Procedural guidance: Boeing Alert Service Bulletin B787-81205-SB340062-00, Issue 01, dated 23 December 2024.
• Later revision accepted: operators may use the procedures of Issue 002 of the Service Bulletin, dated 11 August 2025.
• Timing rule: where the bulletin’s compliance tables refer to its own issue date, operators must instead use the AD’s effective date.

Airlines sought relief; the FAA declined

Two carriers backed the proposal without change: the Air Line Pilots Association, International (ALPA) and Boeing. Seven others pressed for changes, and the FAA rejected the substantive ones.

• Air Canada and United Airlines asked the agency to accept Issue 002 of the Service Bulletin, which corrects material kits and consumables and updates installation instructions; the FAA agreed this may be used.
• EVA Air and Turkish Airlines asked for the applicability to cite Issue 002 of the Requirements Bulletin; the FAA refused, noting Boeing has not released that revision because Issue 002 of the Service Bulletin does not alter the required-for-compliance steps.
• American Airlines, Turkish Airlines and an anonymous commenter sought more time; the FAA declined.
• The Foundation for Aviation Safety asked for a shorter deadline and queried a window of up to five years for work estimated at about 28 hours; the FAA declined.
• An anonymous commenter proposed allowing continued flights under visual flight rules; the FAA rejected that, stating the altimeter is needed for everyday operations and that the AD does not prohibit operation of the affected airplanes.

Cost, lead times and oversight

Carriers argued that parts, not labour, are the binding constraint. American Airlines said Boeing quoted a lead time exceeding 500 days for the required cables, and Turkish Airlines said it shared its kit needs with the manufacturer in March 2025 but still faced supply problems. The FAA said it weighed the manufacturer’s recommendations, the urgency of the unsafe condition and parts availability, and concluded operators have sufficient time within the five-year compliance period.

Alternative methods of compliance may be approved by the Manager, AIR-520, Continued Operational Safety Branch, under 14 CFR 39.19, or by Boeing’s Organization Designation Authorization where the finding meets the airplane’s certification basis and expressly refers to this AD. Technical questions are directed to Frank Carreras, Aviation Safety Engineer at the FAA’s Des Moines, Washington office.

The directive turns a long-running reliability concern into a fleet-wide retrofit obligation with a hard start date and a five-year tail, and it removes the option of simply flying around the defect. For passengers across the 787 network, the practical effect is that every affected airframe will eventually enter a maintenance visit for a cable replacement the regulator considers necessary to preserve safe landing performance.

Source: Federal Register, Vol. 91, No. 215, 9 November 2026, Rules and Regulations, p. 70774 (official reference: AD 2026-22-09).