AD 2022-08-11 Prompted By In-Service Reports Of The Loss Of Display

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 helicopters. 

This AD was prompted by in-service reports of the loss of display and subsequent recovery of certain display units (DUs). This AD requires revising the existing rotorcraft flight manual supplement (RFMS) for your helicopter and disabling the traffic alert and collision avoidance system (TCAS) POP-UP feature for certain DUs. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective May 27, 2022.  

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Bell Textron Canada Limited Model 429 helicopters, serial numbers 57001 through 57369 inclusive, 57371, and 57373. The NPRM published in the Federal Register on December 28, 2021 (86 FR 73708; corrected January 10, 2022 (87 FR 1083)). In the NPRM, the FAA proposed to require revising the existing RFMS for your helicopter and disabling the TCAS POP-UP feature for certain DUs. The NPRM was prompted by Transport Canada AD CF-202018R1, dated November 27, 2020 (Transport Canada AD CF-2020-18R1), issued by Transport Canada, which is the aviation authority for Canada, to correct an unsafe condition for Bell Textron Canada Limited Model 429 helicopters, serial numbers 57001 through 57369, 57371, and 57373. Transport Canada advises that it has received in-service reports of the loss of display and subsequent recovery of the DU manufactured by Rogerson Kratos (RK). 

During an instrument flight rules approach, a Bell Textron Canada Limited Model 429 helicopter lost its center DU display, which then rebooted, and subsequently lost its right-hand side (RHS) DU display, which then also rebooted. Investigation revealed that the DUs' power cycle occurred while in Map-Mode, which was caused by the RK DUs' limited processing capability for excessive null waypoints generated by the Garmin GTN 750/650 GPS/NAV/COMM/MFD. 

Transport Canada also advises that the use of Map-Mode to the center DU should be limited only for Bell Textron Canada Limited Model 429 helicopters equipped with RK DUs and Garmin GTN 750/650 main software version 6.21 or later and that the use of Map-Mode should be prohibited on both the RHS DU and left-hand side DU, if installed.

In addition, Transport Canada advises that a new emergency and malfunction procedure in the event of center DU failure should be implemented. If not addressed, a DU power cycle occurring during flight and consequent momentary loss of display information on the primary flight display and other DUs could result in the unexpected loss of display of important flight parameters to the pilots, including attitude, approach, airspeed, altitude, flight director information, navigation system cues, as well as engine and rotor drive system indications.  

FMI: www.regulations.gov