Monitoring Helicopter Swash Plates Assemblies by Integration of Ferrography and Atomic Emission Spectrometry

Helicopters Swash Plates Assembly allows helicopter steering movement and is defined as a safety system. This system experiences wear and high loads during flight. Following a failure of an assembly that caused a helicopter forced landing, a novel method was developed to monitor the system for early warning based on integration of the Ferrography and Atomic Emission Spectrometry methods. The critical values of metal concentration and particle size in a sample were determined for Ferrography and Atomic Emission Spectrometry methods, respectively. The valuable results allowed developing a decision-making flowchart. The integration of the methods yielded complementary detectability and extended detection range. Over a period of 7.5 years, 37 different assemblies were monitored, yielding a wide data base of 1618 samples. Recently, four assemblies were removed from helicopters following the method alerts and found as True Positive cases, in addition one control assembly was dismantled and found True Negative. Nowadays, this method is implemented on helicopters in service.