Amendment 23-53 added the current rule. The current amendment requires the installed engine to withstand ingestion of rain, hail, ice, and birds at a level not less than that established under engine certification. Under Amendment 23-53, the airplane applicant needs to evaluate the conditions used to address rain, hail, ice, and bird ingestion during engine certification and how the installation relates to these conditions. Means of Compliance When showing compliance with the rain ingestion requirements for all amendment levels of Sec. For airplanes with a certification basis prior to Amendment 23-53, test is typically required if the specific operating considerations contained in the part 23 rule were not addressed during engine certification.
Some examples are inlet system channels, indentations, and so forth.
These are typical of turbopropeller or S- duct type inlets that have complex geometry to allow water pooling. However, due to the large diversity of turbine engine installations in part 23 airplanes, all installations should be evaluated to determine if areas of concern exist. For example, there are turbofan installations that use S-style inlet ducts that may have areas of concern. Therefore, part 23 turbine engine installations typically require testing since the vast majority of these are turbopropeller installations. Also, since the rain ingestion requirements in part 33 were not added until Amendment 33-6, the airplane applicant needs to evaluate the engine's certification basis to determine if the engine has been subjected to part 33 rain ingestion testing.