Corroded hardware is leaving Airbus A350 cockpit escape hatches difficult to open from the outside, leading Airbus to redesign the affected parts and prompting EASA to order modifications for the affected in-service fleet.

EASA’s draft airworthiness directive (AD), issued Dec. 1, would give affected operators 72 months to upgrade the hatches. The AD is based on an Airbus service bulletin issued Nov. 10 explaining the issue and providing modification instructions. 

“An occurrence was reported where, during an inspection of its fleet, an A350 operator found that cockpit escape hatches were difficult to open from the inside, and several hatches were found impossible to open from outside,” EASA’s AD said. “Further investigation results indicated that the cockpit escape hatch mechanism is suffering from corrosion due to condensation penetrating inside the mechanism.”

Airbus determined that hatches remain usable from the inside, but “might not be operable from the outside,” EASA said.

The manufacturer developed a new hatch with better corrosion protection and introduced it on the A350 production line. Aircraft built before the modification will need to be retrofitted if they are covered by the EASA directive. Other regulators are likely to adopt the mandate. 

Airbus said the issue affects both A350-900s and -1000s. EASA’s AD does not say how many of the 390 in-service A350s have the original hatch. 

The proposed AD’s public-comment period closes Dec. 29.