The first PT6A-6 turboprop engine, rated at 500 shp, was delivered in December 1963 with an initial life of 600 hr between overhauls. By early 1971, over 4000 engines had been delivered, the output had grown to 900 shp, and times between overhaul in excess of 5000 hr had been reached. The technology spawned by the PT6 has resulted in the development, by UACL, of a host of turboprop, turboshaft, and turbofan engines, along with industrial derivatives. In over 5 million hr of operation, the PT6 has clearly demonstrated how sound technology and persistent development can meet the exciting challenges of the 1970s.
