Ever wonder why the F-16 is the F-16? Or why the F6F Hellcat is what it is? What do those letters and numbers mean?
Well it turns out, there is a perfectly reasonable explanation for the old designation and new designation systems. In 1962 the Armed Forces went to a universal naming system so that no matter which branch was using an airframe design it was universally recognized. This resulted in all in service planes being renamed to meet the new scheme. At the time there were actually 3 different F4’s.
Remember all things called an M1? Yeah. It got nuts. In short the old name scheme was based on manufacturer more than differentiating the plane. While you or I or any other service member might not be able to distinguish what F4 was being talked about, the full name code would tell a maintenance crew what they were working on. But only the maintenance team and only if they knew. Even if the plane was in multiple service branches the Navy and Air Force used different systems. 1962 changed that.
Starting with F1 and going to… F35, the Lightning II made by Lockheed Martin
So, in short, we went to a chronological model designation system in 1962 and we have had 35 models come through since. The letter designations indicate different iterations or different job types and roles.