AD 2026-13-15 Airworthiness Directives; The Boeing Company Airplanes

Models named: 707-100 Long Body, -200, -100B Long Body, -100B Short Body series, 707-300, -300B, -300C, -400 series, 717-200, 727. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to all The Boeing Company airplanes identified in paragraphs (c)(1) through (9) of this AD, certificated in any category. (1) Model 707-100 Long Body, -200, -100B Long Body, and -100B Short Body series airplanes, and Model 707-300, -300B, -300C, and -400 series airplanes. (2) Model 717-200 airplanes. (3) Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes. (4) Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8F-54, DC-8F-55, DC-8-61, DC-8-62, DC-8-63, DC-8-61F, DC-8-62F, DC-8-63F, DC-8-71, DC-8-72, DC-8-73, DC-8-71F, DC-8-72F, and DC-8-73F airplanes. (5) Model DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), DC-9-33F, DC-9-34, DC-9-34F, DC-9-41, and DC-9-51 airplanes. (6) Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, and DC-10-40F airplanes. (7) Model MD-10-10F and MD-10-30F airplanes. (8) Model MD-11 and MD-11F airplanes. (9) Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes. (d) Subject Air Transport Association (ATA) of America Code 34, Navigation.

Comply with this AD within the compliance times specified, unless already done.

(1) For purposes of this AD, a “radio altimeter tolerant airplane” is one for which the radio altimeter, as installed, demonstrates the tolerances specified in paragraphs (g)(1)(i) and (ii) of this AD, using a method approved by the FAA. No actions are required by this AD for radio altimeter tolerant airplanes. (i) Tolerance to radio altimeter interference, for the fundamental emissions (3.7-3.98 GHz), at or above the power spectral density (PSD) curve threshold specified in figure 1 to paragraph (g)(1)(i) of this AD. Figure 1 to Paragraph (g)(1)(i)—Fundamental Effective Isotropic PSD at Outside Interface of Aircraft Antenna ER30JN26.013 (ii) Tolerance to radio altimeter interference, for the spurious emissions (4.2-4.4 GHz), at or above the PSD curve threshold specified in figure 2 to paragraph (g)(1)(ii) of this AD. BILLING CODE 4910-13-P Figure 2 to Paragraph (g)(1)(ii)—Spurious Effective Isotropic PSD at Outside Interface of Aircraft Antenna ER30JN26.014 (2) For purposes of this AD, a “non-radio altimeter tolerant airplane” is one for which the radio altimeter, as installed, does not demonstrate the tolerances specified in paragraphs (g)(1)(i) and (ii) of this AD.

This AD was prompted by the 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 Lower C-Band) when operating in Canadian airspace, and a determination that during 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. The FAA is issuing this AD to address 5G Lower C-Band interference that could result in increased flightcrew workload and could lead to reduced ability of the flightcrew to maintain safe flight and landing of the airplane.

None.