Aerophilately

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.

Scope
The scope of aerophilately includes:
 * airmail postage stamps, both official and unofficial (see list of US airmail postage here)
 * other types of labels (such as airmail etiquettes)
 * postal documents transmitted by air
 * postal markings related to air transport
 * rates and routes, particularly first flights and other "special" flights
 * mail recovered from aircraft accidents and other incidents (crash covers)

While most of the study of airmail assumes transport by fixed-wing aircraft, the fields of balloon mail, dirigible mail, zeppelin mail, missile mail, and rocket mail are active subspecialties. Astrophilately, the study of mail in space, is a related area.

Organizations
International Federation of Aerophilatelic Societies (FISA) is the umbrella organization for aerophilately though aerophilatelists have formed a number of organizations around the world; many of them put out a variety of specialized publications. Federation Internationale de Philatelie (FIP) also maintains a commission.