That’s not the reason. English radio and german language is something entirely else. Radio is often prone to electromagnetical disturbance, communication isn’t always “loud and clear”. But there are several words in “official” comms, possibly in EASA, not FAA, that stand alone… “fire” is one of them (“takeoff” would be another one) and when your plane is fuming it’s likely that your radios are massively damaged… Anything with an english i in it needs to be made as clear as possible, the shorter the word with the i the clearer it must be pronounced. “nine” and “fire” both have only one pronounced syllable and therefore they added the “r”.
German Nein is not existant on german radio… it’s “negativ”. same reason. Short i.
For the phonetic P (Papa) they actually chose the german pronounciation for Papa (Daddy), which in english writing would be sth like Pahpah. Well, the german a is actually spoken similar to the english u so it’s quite weird to WRITE it that way lol. It’s an “a” like it “part” Of course thousands of accents around the world make it sound differently everywhere. In Saxonia in Germany it would probably sound like Bobo with a cold nose… hide
In USN I learned it as PAPA. Like O is Oscar. There is some variation in it around the world. I do not know if it has been updated for some reason, but trust me Z is Zulu.
Weeel… if you’re roleplaying the ww2 RAF it’d be Apple/Beer/Charlie/Dog, at some point so… partly right
The main purpose of phonetic alphabets - and RT lingo in general - is clarity, so if you’re being unmistakeably clear then that is enough. Papa and paPa are both unmistakeable.
English, much like the people who constructed it, is a mashup of imports fighting to find a useful equilibrium ( I say that as a typical UK mashup ).
( I say that as a typical UK mashup ).