is not. The Ryan XV-8 ("Fleep") had already existed so the Harrier should have been named AV-12. The "FB-111" is incorrectly named as it was originally a fighter that was adapted to the bomber role. Thus it should have been designated BF-111. The Boeing 747 has three different designations in U.S. service - E-4, (V)C-25 and AL-1 - which violates the basic purpose of the system. The CC-130J Hercules referred to the stretched C-130J-30 Hercules. The -30 suffix was not supportable in the system, so a modified mission letter had to be added. Hence, the CC-130J is a cargo aircraft "modified" for the cargo role. This was later dropped. The CC-130J should not be confused with the CC-130 Hercules operated by the Royal Canadian Air Force. The first "C" identifies the aircraft as a Canadian asset. Canada later acquired C-130Js as CC-130Js. Many manufacturers have used non-standard modifiers for commercial purposes; for instance, the Spanish F/A-18 Hornets were 'designated' EF-18 by McDonnell Douglas (the E standing for "España"), and AH-64D Apache helicopters were designated WAH-64 by licensed manufacturer Westland. Non-standard series letters, especially ones the U.S. Air Force has no intention of progressing to, are often used to designate the intended country of use, such as I (Israel - e.g. F-15I), J (Japan), K (South Korea or United Kingdom), S (Saudi Arabia) and SG (Singapore). See also United States military aircraft designation systems 1962 United States Tri-Service aircraft designation system 1963 United States Tri-Service missile and drone designation system List of U.S. DoD aircraft designations List of US DoD MDS designators for missiles, rockets, probes, boosters, and satellites List of undesignated military aircraft of the United States Notes References External links Current Designations of U.S. Military Aerospace Vehicles, Andreas Parsch United States Military Aircraft Designations, Vic Flintham Guided missiles Rocketry Designation Military aircraft designation systems Naming conventions United States military aircraft