Guys, you mean the short call from the HR guy that crosschecks with you again your experience? Plus you have to say "yes" or "no" when he reads the requirement "checklist" to you?
I think it is mainly an english test imho. I am a DEC.
But I learned that FO/Cadets are threated different in terms of contracts, could be that the phone interview is different as well in their case. For Captains the phone "interview" is a piece of cake.