Ensuring a proper operation of the engines over their lifetime is an important air safety aspect. Even though the recent engines are highly reliable the number of accidents due to an incorrect crew response following an Engine malfunction has remained constant for many years. This prompted this study and it reveals that flight crews are not always able to identify and understand engine malfunctions precisely which leads to needless engine shutdowns, incidents and accidents. The scope of this Book is to provide basic guidelines to identify Engine failures/malfunctions and to give operational recommendations in case of Engine malfunction. It can be accomplished using SOM maps by Clustering the various engine parameters based on the parametric variations influenced by the faults,SOM maps are generated and they are stored as the failure template. In addition to their traditional tool based quantitative inspection of some measured variables to detect any deviation from the normal behavior making it possible to anticipate possible faults. By proper detection of the faults suitable malfunction response will be displayed to the crew for their assistance enhancing reliability and safety.