Job Fairs
I have attended many job fairs and also was lucky enough to work a few of them, what you said was correct. Resume and cover letter , most won't want a cover letter cause it's just too much to keep when your accepting 1000 of them in a day.
As far as the recruiter goes , be your self and humble and explain why you want to work for xyz airline , keep this in mind while talking to these guys, they are gonna be talking to 400 guys just like you, who have resumes just like yours or even better. ASK questions about what's going on but also be informed on the airline yourself , know the bases they have and aka if any changes are being rumored etc , do a little research before you go on that airline, get the recruiter to like you and remember you, and keep in mind it doesn't matter what you talk about with these guys it's just important to keep the conversation going long enough to make a impression. Don't be overwhelmed by how many guys are there in suits doing exactly what your doing, I remember going to my first few and man it was almost depressing and overwhelming. Don't be the guy who looks down with his tail between his legs that appears to be shy and with shaky hands while handing over your resume , be grateful keep your manners in and go in and kill it , while getting the job you want .
Sorry about the spelling , replying with my phone ,
Good luck , hope this gives you some guidance