I think you'd be better off trying to get a general flight chat off the ground first, before you worry about grouping people into individual chats per flight. H

I think you'd be better off trying to get a general flight chat off the ground first, before you worry about grouping people into individual chats per flight. Hard enough to bootstrap that, but if you did, I would recommend adding tags for Flight Numbers, Airlines, and Airport Codes, and attach those tags to the messages in the chat (as badges next above the message). Ask the user what their next upcoming flight details are. Let the user save those deets. Then once you've gotten enough users and the chat room gets noisy enough, introduce filters, where you can filter by airport code, flight number, airline, etc. Bootstrapping is hard, but I would promote the chat in various subreddits and facebook groups and consumer discussion forums or any interest groups about flying and travel in general.