Airworthiness Directives; Agusta S.p.A. Model AB139 and AW139 Helicopters
We are adopting a new airworthiness directive (AD) for the specified Agusta S.p.A. (Agusta) Model AB139 and AW139 helicopters. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The aviation authority of Italy, with which we have a bilateral agreement, states in the MCAI that during the installation of a fire extinguisher bottle on a new helicopter, it was found that the electrical receptacle/connectors on the bottle which commands the firing of the extinguishing agent were swapped between engines No. 1 and No. 2. This condition could affect helicopters already in service and fire extinguisher bottles of the same part number in stock as spare parts. If not corrected, an improperly wired fire extinguishing bottle might cause the extinguishing agent to be discharged toward the unselected engine when the system is activated, rather than toward the engine with the fire. This AD requires determining if each engine has the proper outlet end on the electrical receptacle/connector that attaches the firing cartridge to the fire extinguisher bottle, and if not, replacing the fire extinguisher bottle. This AD is intended to prevent the fire extinguishing agent from not discharging toward the engine with the fire, which could result in loss of the helicopter due to an engine fire.