The objective of this task is to consider the need to improve the ability of aircraft engines to be able to cope with the ingestion of birds that can reasonably be expected to be experienced during the service life of the engine. This will be achieved by evaluating whether the current engine certification specifications (CS-E) that require demonstration of the ability of the engine to continue to operate following the ingestion of small and medium birds into the core of engines are sufficiently robust in the current environment. In addition, an evaluation of the current CS-E for the demonstration of large-flocking-bird ingestion to be applied to engines with an inlet area of 1.35-2.5 m2 will be considered based on service experience. Amendments to CS-E will be developed and proposed as required based on this analysis, which will further mitigate the risk of an unsafe event resulting from an engine bird ingestion.