Proactive maintenance philosophy Poractive maintenance philosophy for aging aircraft through corrosion induced risk assessment: An analysis on Herbin Y-12 aircraft fleet of Sri Lanka Air Force

Abstract

Corrosion of the aging aircraft structures is a serious problem with long term effects. Corrosion takes place, due to the tendency to getting stabilized by reducing latent energy in thermodynamical aspect, on the metal structures and degrades the metal. Different types of corrosions can be identified on the aircraft structures. However, the primary corrosion methods are: Surface, Pitting, Galvanic, Filiform, and Exploitation corrosions. If corrosion is not detected before it reaches the critical stages, it may lead to instantaneous failures. Due to the possibility of strength losses caused by the pits, cavities or grain degradations developed inside the metal, it could also cause catastrophic events depending on the nature of the part failed. To prevent such events from happening this research was carried out to find a solution for the aging aircraft performance falling problem. When an aircraft gradually reaches its service life the output such aircraft delivers will be decreased compared to the previous years. It is understood that a new maintenance philosophy should be introduced to address this problem arising all over the world. To address this problem, the first step is to identify the factors which effects the failures of an aging aircraft. It has been found out that the corrosion and fatigue will play a major role in problems which were arise in aging aircraft. From those two factors corrosion can be regarded as the main factor which increases the downtime of an aging aircraft. Hence the newly developing maintenance philosophy was deployed on the corrosion factors. With the aid of a risk matrix which categorizes high, moderate and low risk areas with respect to corrosion failure it was possible to find the high risk areas from those corrosion prone areas. Generating a statistical formulation is one part. And this study is restricted to the area of corrosion, but many fields are to be studied regards the aging aircraft, such as fatigue. The continuations of this research will result more effective, efficient and more subjective..