i am doing a thesis project right now. it's also a LAN-based flight reservation and ticketing system. i can help you if you like. just provide some details about what you wanted to know.
but i wanted to give you a little piece of advice based from my own experience. first, research about relational database of airline reservation system. you can find lots over the net. next, also do research about the airline industry from the very least important detail up to the most important one. it'll help you have a good start in developing the system. and lastly, post your codes if you have questions. it sure helps!
if you have other questions, just ask me. i'm here to help. if i can't reply on time, it just mean that i'm busy doing the system. but i regularly visit this site because i am also asking for help from the experts.
good luck and God bless!