Airbus A380 operators have been ordered urgently to update the type’s flight manual with new procedures intended to prevent the risk of structural damage from bleed-duct rupture.
The emergency directive from the European Aviation Safety Agency follows previous measures imposed two years ago, when damage to an aircraft was traced to uncontrolled overpressure in the pneumatic system following a valve closure during take-off.
While the flight manual was updated as a result, EASA states that new cases of engine bleed-duct rupture have emerged, leading to structural damage in a “critical” area.
EASA had previously ordered installation of a new software standard, version 6.4, for the engine bleed air system. This was intended to avert the overpressure scenario, and consequent rupture, when the aircraft takes off with bleed air supplied by the engines and when at least one pack is used.
But EASA says, in its latest directive, that this scenario is “not prevented” when the aircraft takes off with both packs off, or when bleed air is supplied by the auxiliary power unit.
Airbus updated the flight manual procedures on 1 August, and EASA is ordering A380 operators to remove the previous procedural revision and incorporate the latest change before the next flight.
The directive covers all aircraft in the A380 fleet, both Rolls-Royce Trent 900- and Engine Alliance GP7200-powered versions.
EASA had previously explained that the original concern had been triggered by a “double and dependent failure”, during take-off, of the high-pressure value and pressure-regulating valve, which had led to the closure – by design – of the overpressure valve, and subsequent bleed-duct rupture.