The airline should take a leaf out of the cop's book.
For several decades I ran a high tech company in California where the turnover of employees in there 20's and early 30's was high. On several occasions I got a call from the FBI, Los Angeles PD and LA county sheriff dept. wanting to stop by and chat about former employees who had moved on and were now applying for positions with the above law enforcement agencies. What was interesting was some of the folk they wanted to get a feel for had left my company several years earlier and had had a few jobs since but the HR dept at the cops still sent someone round to chat about what type of people they were. When i told the cop during the meeting that the person in question was a hard worker with good attendance etc. they waived that off and focused in on my impression of the candidates social skills and asked questions like "did they have ever hang out with other staff after work? i.e. go drinking or bowling or socializing etc. I realized they were looking beyond your usual HR **** and trying to get a read on their human skills and interaction. Maybe the airlines should look at this?