The American Air Mail Society has issued Volume 1 of the 7th Edition of their Catalog and you can buy it through the American Philatelic Society's publications division. The plans are for Volume 2 and Volume 3 of this new 7th Edition to be published this year, 2015, though time will tell if they can get both of these volumes out this year or just one of them. If you have any interest in air mail covers you really should join the American Air Mail Society. Their annual dues are a modest $30 and for that you get their Airpost Journal magazine delivered to your house plus all kinds of connections with others interested in aerophilately. You also get a discount rate on their publications including the famous Air Mail Catalogs.
Here is a link to their website:
http://www.americanairmailsociety.org