Airworthiness Directive · Amendment 39-17979 · Instruments
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, as identified in paragraphs (c)(1) and (c)(2) of this AD.
(1) Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes.
(2) Model 777-200, 777-200LR, 777-300, 777-300ER, and 777F series airplanes.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, and Model 777 airplanes. This AD was prompted by testing reports on certain Honeywell phase 3 display units (DUs). These DUs exhibited susceptibility to radio frequency emissions in WiFi frequency bands at radiated power levels below the levels that the displays are required to tolerate for certification of WiFi system installations. The phase 3 DUs provide primary flight information including airspeed, altitude, pitch and roll attitude, heading, and navigation information to the flightcrew. This AD requires replacing the existing phase 3 DUs with phase 1, phase 2, or phase 3A DUs, and for certain replacement DUs, installing new DU database software. We are issuing this AD to prevent loss of flight-critical information displayed to the flightcrew during a critical phase of flight, such as an approach or takeoff, which could result in loss of airplane control at an altitude insufficient for recovery, or controlled flight into terrain.
Within 60 months after the effective date of this AD: Inspect to determine if any phase 3 DUs are installed. If any phase 3 DUs are installed, within 60 months after the effective date of this AD, do the applicable actions required by paragraph (g)(1) or (g)(2) of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the phase number of the DUs can be conclusively determined from that review.
(1) For Model 737 airplanes: Remove all phase 3 common display system (CDS) DUs and replace with phase 1, phase 2, or phase 3A CDS DUs. If any phase 3 CDS DUs are replaced with phase 3A CDS DUs, replace the phase 3 CDS DUs and install new database software into the display electronics units, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-31-1471, dated November 29, 2012.
(2) For Model 777 airplanes: Remove all phase 3 DUs and replace with phase 1, phase 2, or phase 3A DUs. If any phase 3 DUs are replaced with phase 3A DUs, replace the phase 3 DUs and install the DU database software into the left and right airplane information management system core processor module/graphics generator, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-31-0187, dated November 29, 2012.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
