A better view of the original forward fuselage before its conversion to C-3605 and the addition of the extended forward fuselage housing the Lycoming turboprop engine.

C-509 is shown here in its original configuration, with Hispano-Suiza piston engine and twin-fins, before conversion to C-3605 (along with 23 other C-3603s), with a Lycoming T53 turboprop engine in an extended nose and with an additional (central) fin. Most were used in the target towing role, with just two used as trainers. The C-3605 was eventually retired in 1987.