Is There A First Flight Club Or Organization?

For earlier covers all mail that was on a first flight received the special cachet for that one flight. More recent first flights had all covers that were sent with a cover letter requesting first flight sevice would get the cachet. There are not many new routes these days, but if you are interested you should join the American Air Mail Society and request to be notified by their "Advance Bulletin Service Manager" on how to get your covers on a first flight and get the special cachet if one is being provided. Because modern jet airliner can carry so much mail the regular mail does not get special cachets and there is no way to tell if a cover was on the inaugural flight.