Airworthiness Directive · Amendment 39-21982 · Navigation
The Boeing Company Airplanes
Superseded. A later AD replaced this one: AD 2023-12-14. Comply with the one in force.
This AD applies to all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, and 747-400F series airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, and 747-400F series airplanes. This AD was prompted by a determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band), and a recent determination that during takeoff, approach, landings, and go-arounds, as a result of this interference, certain airplane systems may not properly function, resulting in increased flightcrew workload while on approach with the flight director, autothrottle, or autopilot engaged, which could result in reduced ability of the flightcrew to maintain safe flight and landing of the airplane. This AD requires revising the limitations and operating procedures sections of the existing airplane flight manual (AFM) to incorporate specific operating procedures for takeoff, instrument landing system (ILS) approaches, non-precision approaches, and go-around and missed approaches, when in the presence of 5G C-Band interference as identified by Notices to Air Missions (NOTAMs). The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 2 days after the effective date of this AD: Revise the Limitations section of the existing AFM to include the information specified in figure 1 to paragraph (g)(1) of this AD. This may be done by inserting a copy of figure 1 to paragraph (g)(1) of this AD into the Limitations section of the existing AFM.
(2) Within 2 days after the effective date of this AD: Revise the Operating Procedures section of the existing AFM to include the information specified in figure 2 to paragraph (g)(2) of this AD. This may be done by inserting a copy of figure 2 to paragraph (g)(2) of this AD into the Operating Procedures section of the existing AFM.
Note 1 to paragraph (g)(2): Guidance for accomplishing the actions required by paragraph (g)(2) of this AD can be found in Boeing Multi Operator Message MOM-MOM-22-0034-01B(R2), dated January 28, 2022; Boeing Multi Operator Message MOM-MOM-22-0033-01B(R1), dated January 31, 2022; and Boeing Flight Crew Operations Manual Bulletin TB1-55, “Radio Altimeter Anomalies due to 5G C-Band Wireless Broadband Interference in the United States,” dated January 29, 2022.
