Airworthiness Directives; Eurocopter France Model AS355E, F, F1, F2, and N Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter France (ECF) model helicopters that requires revising the Limitations section of the Rotorcraft Flight Manual (RFM) to prohibit using the landing light except for landing and takeoff until the 40 amp 10P1 and 10P2 contactors are replaced with 50 amp circuit breakers. Also, this amendment requires upgrading the electrical master boxes. This amendment is prompted by three reports of complete loss of electrical power generating systems, except for the direct battery power, due to a combination of high outside temperature and long flight duration with the landing light on that causes the nontemperature compensated trip switches to prematurely trip. The actions specified by this AD are intended to prevent failure of the helicopter power generator systems, loss of the use of flight instruments, and subsequent loss of control of the helicopter.