In order to make the PA-23 Apache into a full six seater, Piper modified the aircraftas the PA-23-250 Aztec with a swept tail and two 250 hp Lycoming O-540 engines. There was also lower powered version - the Apache 235. The Aztec was updated, initially as the Aztec B with a longer nose and then as the Aztec C to F with Tigershark engine nacelles.