FAA directive on the A330-900 flight control computer after a triple 'PRIM FAULT' at touchdown
FAA final rule on Airbus A330-941 after a triple PRIM FAULT at touchdown: new FCPC standard, parts prohibition, 39 US airplanes, effective 1 December 2026.
The FAA has issued a final airworthiness directive for Airbus A330-941 airplanes, the A330-900neo variant, after an event in which the aircraft recorded a triple "PRIM FAULT" in its flight control primary computer (FCPC) at touchdown. The rule affects 39 airplanes on the US registry.
What happened
According to the rule, the event was a triple PRIM FAULT in the FCPC at the moment of touchdown. The PRIM FAULT message means that the primary flight control computer has detected a fault. The FAA did not publish a full investigation in the rule, so we are not describing the aircraft or the flight beyond what the rule says.
What the directive requires
- Install a new FCPC standard and the applicable concurrent modifications, as specified in the European Union Aviation Safety Agency (EASA) directive it refers to, EASA AD 2025-0208.
- Prohibit the installation of certain parts that the FAA says are not acceptable on these aircraft.
The directive takes effect on 1 December 2026. The FAA proposed the change earlier in 2026 under docket FAA-2026-8782 and received one comment on the proposal.
Why this matters
The flight control computers are part of the system that moves the aircraft's control surfaces, so a fault there is taken seriously even when the aircraft lands safely. The directive does not ground the fleet. It requires a hardware and software change that the airline makes during maintenance.
Sources
Featured image: Photo: Steve Lynes, CC BY 2.0, via Wikimedia Commons. Airbus A330-900neo F-WTTE. Source
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