Airworthiness Directive · Amendment 39-13116 · Eurocopter France Model AS350B3 Helicopters
Eurocopter France Model AS350B3 Helicopters
Model AS350B3 helicopters, serial numbers (S/N) 3062 and earlier, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) model helicopters that requires inspecting the ASU No. 2 printed circuit board (PCB) to determine if the resistor R8 is installed, and if it is not installed, replacing the PCB with an airworthy PCB with that resistor installed. This amendment is prompted by the discovery of a PCB without a critical resistor that polarizes the voltage regulator that regulates electrical power to a critical warning light, a critical caution light, and the main rotor revolutions per minute (RPM) signal to the vehicle engine management display (VEMD). The actions specified by this AD are intended to prevent the malfunction of the two critical lights and the rotor RPM signal to the VEMD, failure of these components to timely alert the pilot to the associated malfunctions, further helicopter damage because of these malfunctions, and subsequent loss of control of the helicopter.