Summary
This document proposes the adoption of a new airworthiness directive (AD) for specified Eurocopter France (Eurocopter) model helicopters. This proposal would require 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 proposal is prompted by the discovery of a design deficiency that permitted the installation of a non-fireproof breather pipe. The actions specified by the proposed 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.