A specialized area of stamp collecting concentrating on stamps or covers carried by air.

the collection and study of airmail stamps

Stamp collecting that focuses on stamps or postage relating to airmail.

The collecting, preservation, and study of airmail stamps. Cat. Designation: "C"

Aerophilately is the branch of philately that specializes in the study of airmail. Philatelists have observed the development of mail transport by air from its beginning, and all aspects of airmail service have been extensively studied and documented by specialists.