Given your requirements of no-data-or-WiFi, this is impossible if you want “live” data, such as the flight’s current location and current ETA.

That leaves ‘static’ data, such as flight schedule, updated to the time you boarded. I use Trip-it. Flight details end up in the app if I forward the itinerary to plans at TripIt.com, or give it access to scan my gmail address. It also works for hotel and car reservations, usually.

Trip-it will keep up with flight delays by the airlines, at least until you go airline mode.