There is also some confusion I believe over the name of the aircraft. Some resources call the Naval-modified P-51D an “ETF-51D”, but this isn’t correct. The aircraft never had a change of name while it was in the hands of the Navy (not even a BuNo assigned to it), and if it had, it wouldn’t have been in that form, for a North American product in U.S. Navy hands would have had a “J” in the title. The term “ETF-51D” came later, in the post-war years, with the NACA operated F-51D’s. “ET” was added to the front of the title, meaning “Extended Tail”, as NACA added taller tail fin caps to their F-51D’s (which Cavalier later copied and used in their Mustang conversions).

There is the possibility that this particular airframe, 44-14017, was handed over to the NACA after the carrier trials, and later became an “ETF-51D” in the hands of the NACA. There is a photo of the ETF-51D “NACA 102” which appears to show the same rudder and lower tail-cone modifications as seen on 44-14017 during the carrier trials (note the Bell X-1 style model airframe profile mounted to the wing). Photo comes from the NASA archives: http://i7.photobucket.com/albums/y282/Bomber_12th/GPN-2000-001252.jpg