Aerophilately

This 1932 Canadian "first official flight" cover, Great Bear Lake to Rae (now Behchoko), includes both a special cachet and a surcharged airmail stamp.

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.