You can expect several TMAAT (tell me about a time...) style questions that are designed to reveal a little about who you are as a person in various categories such as leadership, customer service, integrity etc. You can also expect to be asked why you want to work at Frontier and some questions to find out what you know about the airline and why you believe you would be a good fit. There's also a situational interview portion where they ask you to role play a Frontier pilot and respond to various events/scenarios that occur.