AD 2023-21-05 Airworthiness Directives; Thales AVS France SAS Flight Management Computer Navigation Modules

This AD applies to Thales AVS France SAS flight management computer navigation modules (FMC2 NAVM), part number (P/N) C13084CA03, installed on, but not limited to airplanes, certificated in any category.

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

(1) Within 30 days after the effective date of this AD, revise the Limitations Section of the existing airplane flight manual (AFM) for your airplane by adding the information in Table 1 to the introductory text of paragraph (g)(1) of this AD and Table 2 to the introductory text of paragraph (g)(1) of this AD. Table 1 to the Introductory Text of Paragraph ( g )(1)— Limitations To Operate the Flight Management System (FMS) of the Airplane [Formulated as instructions to the Flight Crew] Limitation No. Limitation/instruction 1 For Procedure Turn, Tear Drop trajectory, specified turn direction or arc to fix leg in published navigation procedure, disengage FMS Navigation mode and engage Track mode with the expected Track target. 2 When coupled to the AFCS, do not perform a Direct To while established in Turn. 3 Do not revise the flight plan until GO AROUND safe altitude (as per Standard Operating Procedure) has been reached. 4 Initialize the flight plan with at least an intermediate waypoint between departure and destination. 5 Before flying a procedure (including associated missed approach) that requires to fly over a waypoint, check that the fly-over flag is displayed on MCDU FPLN page beside the constrained fix, as expected in the published chart. If the fly-over is missing, it shall be set manually. 6 Do not use Vertical Step function. 7 Do not activate the data save command. 8 Do not use Offset function. Table 2 to the Introductory Text of Paragraph ( g )(1)—FMS User Manual Limitations Limitation No. FMS user manual limitations 1 Operate the FMS respecting the limitations. 2 Only operate the FMS of the airplane with a specifically trained crew, as defined in the FMS User Manual, for awareness and training on the mitigation means to recover from the issue “straight leg bypassing following arc to fix leg.” (i) Inserting a copy of this AD into the Limitations Section of the existing AFM for your airplane satisfies the requirement of the introductory text of paragraph (g)(1) of this AD. (ii) The actions required by the introductory text of paragraph (g)(1) of this AD may be performed by the owner/operator (pilot) holding at least a private pilot certificate and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439. (2) Within 30 days after the effective date of this AD, update the database for your Thales FMC2 NAVM, P/N C13084CA03, with a database that does not contain the procedures specified in section II of Thales Service Information Letter F9111-J70859DN-00, issued January 18, 2022 (Thales SIL F9111-J70859DN-00). (3) As of the effective date of this AD, do not install a database for your Thales FMC2 NAVM, P/N C13084CA03, unless it does not include the procedures specified in section II of Thales SIL F9111-J70859DN-00.

This AD was prompted by reports that, due to software issues, certain FMC2 NAVM navigation modules provide erroneous data to the flight management computer, compromising safe flight of the airplane. This condition, if not addressed, could compromise the safety margins of the airplane and result in controlled flight into terrain.

None.