French ATC. Coo, that brings back memories.
In the '70's, the French Air Traffickers were much prone to go on strike (I spit on your aircraft etc) (for those in the know).
Returning to UK, ex Gib, in a Dominie (that's still flying!! I see) we came under control of Medan Radar, whose civilian complement were on strike. So, the French military ATC controllers were 'helping out'.
So, after much farcical Franglais between ourselves and our 'military controller', we were cleared to FL210 at 'xyz beacon' at such a time. (I forget the details exactly).
Being 'the pond life new boy', I was down the back on a headset listening, in awe, to all the exchanges when up pops on frequency a Spantax jet heading south. Who promptly adopted the French language whilst chatting to Medan.
Now, I did then and still now, have schoolboy French (le plume de ma tante etc) but my (very sparse) translation skills rapidly twigged that both we, the Dominie, and the Spantax were to arrive overhead the 'xyz' beacon at the same level and at the same time. Hmm, thinks I, not a good plan.
Being an LAC u/t Opsy at the time, and having no idea how the aircraft intercom worked, I plucked at the sleeve of my boss, the staff nav. After 'Sir,Sir I think the French controller has just.....etc', A degree of consternation arose from the Pilot and his Pilots Assistant resulting in much "confirm" and "Say again" transmissions being broadcast to/from Medan.
We eventually got home safe and sound after avoiding a possibly sad flying statistic.
The outcome. I was bought beer. I was ill. OK, I was young.
As an aside, I believe Medan Radar was given a different name shortly afterwards. As the initial call 'Medan', in Franglais and other accents, sounded very much like 'Mayday'.