Airbus helicopter windows need regular greasing to open in an emergency

The US aviation regulator is ordering owners of certain Airbus H160-B helicopters to regularly lubricate the emergency exit windows. This is to ensure the windows can be jettisoned quickly in an emergency, following reports of them sticking.

This is a small, specific fix for a new helicopter model. It means that operators of these helicopters now have a new, mandatory maintenance task. The goal is to prevent a failure that could trap people inside the aircraft during an emergency.