Warns Of Possible Loss Of Electric Power Due To Water Intrusion

The FAA has issued a Special Airworthiness Information Bulletin (SAIB) for two models of Airbus helicopters warning of the possibility of a total loss of electrical power due to water entering into the cabin.

The SAIB covers Airbus Helicopters AS350 and AS355 aircraft. According to the FAA, during a flight, the pilot of an AS355 helicopter was splashed with water, while the source of the water could not be identified. Immediately after, the display on the Vehicle and Engine Multifunction Display (VEMD) was affected. A few days after this incident, a total loss of the electrical power system in-flight was reported and after landing it was not possible to stop the engines with the dedicated selectors. The engines were stopped using the fuel shut-off controls.

Further analysis determined that the loss of the electrical power supply was probably due to water ingress, affecting the electrical connectors of the instrument panel equipment items. This was likely caused by a partially obstructed or blocked drain of the cabin ventilation air scoop. Depending on the flight parameters (speed, attitude, rain, etc.), the water inside this scoop may ingress inside the cabin and can affect various avionics and vehicle systems.

The FAA recommends the inspection of the ventilation air scoop drain for blockage, and the removal of any blockage found.

(Image from file)

FMI: www.faa.gov