Considerable operational experience has been acquired in South America, Africa, Europe, Southeast Asia, and in other remote areas in STOL type aircraft operating from extremely short, primitive, unimproved fields. This type operation not only makes certain special demands of the engine, but also exposes it to a rather hostile environment. The engine is subjected to all types of foreign object ingestion, as well as the fine sand and dust that is stirred up by propeller reversing. This paper describes this type of operation, emphasizing those aspects which make life difficult for the engine. Solutions to some of these special problems are described, as well as activities now in process seeking further improvement.