Potential software malfunction detected in Airbus A350 – EASA springs into action, issues emergency AD

In what could be a recipe for disaster, a potentially critical issue has been detected on the Airbus A350-900 and -1000, which could possibly render the pilots helpless in controlling the stability of the aircraft.


Reportedly, a software bug has been detected on the Airbus A350 which could potentially lead to a loss of elevator control-one of the worst control to be lost.

An elevator is a primary flight control surface that controls movement about the lateral axis of an aircraft-a movement referred to as “pitch”.

Illustrative | Tekno-Port

Therefore, a directive was issued on May 5th and is tentatively expected to go effective from the 9th of May. Apparently, the European Union Aviation Safety Agency (EASA) has asked operators of the Airbus A350-900 and -1000 to amend the applicable AFM (airplane flight manual) and Minimum Equipment List accordingly.

An occurrence was reported where the PRIMary flight control computers (PRIMs) indicated that both elevator actuators were considered faulty.” The airworthiness directive (AD) also states that subsequent investigations had found that incorrect instructions had been implemented with the introduction of the “PRIM P13 standard”, which is part of the Flight Control and Guidance System (FCGS) X13 standard

Published as Emergency Airworthiness Directive 2022-0079-E, EASA

Furthermore, the Airworthiness Directive also stated that subsequent investigations pointed to incorrect instructions being implemented with the introduction of the “PRIM P13 standard”- which also happens to be a part of the Flight Control and Guidance System (FCGS) X13 standard.


The emergency AD by EASA could mean further ADs could possibly follow in the days to come. EASA has set the deadline to MAY 16 within which it expects operators to amend the AFM with a temporary revision (TR), noted as AFM TR 132 issue 1 or 133 issues 1.

Inform all flight crews, and, thereafter, operate the aeroplane accordingly

EASA’s directive stated

Now one might ask, how could a simple “amendment” possibly fix a loss of elevator control?

Reportedly, it is only a software bug “indicating” a malfunction, and there perhaps, might not be an “actual” loss of control of the elevator. In simple words, the bug in itself might not cause issues but the human actions resulting from following that definitely might.


COVER: Aviation Week

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