Having studied Russian, Arabic and Serbo-Croat at University, this actually stifled my promotion in the pilot branch. You have to be 'Above Average' in the air for promotion as a pilot, so when you keep getting pinged off to do 'language' jobs, your flying suffers. I was told by the then Stn Cdr that I had just done an incredible job for a 6-month detachment, but had set my promotion chances back 18-24 months!
I leave next year!