Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, BA, and D Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter model helicopters that requires fireproofing the engine oil tank breather pipe (breather pipe) where it passes through the firewall from the engine compartment to the main gearbox compartment. This amendment is prompted by the discovery of a design deficiency that permitted the installation of a non-fireproof breather pipe. The actions specified by this AD are intended to prevent the spread of fire between two designated fire zones of the helicopter, additional structural damage, and a decrease in the time available to execute an emergency landing.