It amazes me that the United States Military still has such a “colonial” attitude towards R/T. The reluctance for a world power to use the Internationally agreed standard is appalling and does lead to misunderstandings around the world.
I recall back in 1978 flying a F4 in Germany when we suffered a major malfunction with a distinct possibility of having to eject. We declared a Mayday and diverted to the closest airfield. All was going well until on long finals to land when there was a off-putting amount of chat on frequency.
The American Flight Lead was arguing with ATC that his 4 ship had a range slot and his flight should be given priority over inbound traffic. When ATC explained that Mayday 01 was on long final cleared to land he replied “is Mayday 01 his callsign or does he have some kind of problem?”
I could not listen any longer and turned the radio volume fully down and continued to land. This Flight Lead showed a complete lack of understanding of the meaning and use of MAYDAY.
In later years I taught at a TFTS in the USA. Even then the students were taught to declare an IFE (In Flight Emergency) instead of Mayday and PAN. My students were all German and so we ensured that they were taught correctly.
When will they ever learn?