Had three interviews but worked as a summer student before my full time inteview.

Phone interview with HR and 3 directors. They tried to explain the job to me, but they were incredibly vague and couldn't answer any of my direct questions (Is there failure analysis, is this document creating based on specs, what exactly is it I'd be doing?). They also started asking me technical engine questions. I'm a metallurgist at an airplane company, that's what on my resume, that's what was in my cover letter, that's what I told them when they started asking that question. They kept hammering me with engine specific technical questions. Luckily I already had an onsite interview scheduled with a company I actually liked (and subsequently got a job for), or this could have really shaken my confidence! Also, after the interview I sent a standard thank you to the HR rep and asked for contact info for the other interviewers to extend my thanks. She said no but she'd pass along my thanks. I found that incredibly rude!!