You make a good point, but it is not uncommon for engineers to use English around the world. There are so many text books and source materials available in Engl

You make a good point, but it is not uncommon for engineers to use English around the world. There are so many text books and source materials available in English, especially in aerospace. They claimed to use CATIA software for the design, which is originally French but has an English version. I'd be shocked if there is a Persian version of the software. The flip side is that you would really want ground crews to be able to read warnings and such. So while one could justify english on the engineering front, native language makes more sense on a production version.