EASA EAD – Airbus A350 PRIMs indicated both elevator actuators were faulty
IFA Comment: We note the results of the safety assessment have indicated the need for immediate publication and notification.
Airbus S.A.S A350 aeroplanes
ATA – Aircraft Flight Manual – Section Limitations / Normal Procedures – Amendment
ATA 27 – Flight Controls – Master Minimum Equipment List – Amendment
An occurrence was reported where the PRIMary flight control computers (PRIMs) indicated that both elevator actuators were considered faulty. Subsequent investigations identified incorrect instructions had been implemented with the introduction of the PRIM P13 standard, that is part of the Flight Control and Guidance System (FCGS) X13 standard installed in production aeroplanes through Airbus mod 115496, and in-service aeroplanes through Airbus SB A350-42-P017.
This condition, if not corrected, could lead to loss of control of the elevator surfaces, possibly resulting in loss of control of the aeroplane.
To address this potential unsafe condition, Airbus published the AFM TR and the MER, as defined in this AD, providing operational/dispatch restrictions for aeroplanes with FCGS X13 standard installed.
For the reason described above, this AD requires implementation of certain operational/dispatch restrictions.
This AD is considered to be an interim action and further AD action may follow.