This collection contains considerable material relating to aviation history, particularly in western and northern Canada, including material on: the Keng Wah Aviation School for Nationalist Chinese pilots; the RCAF; illustrations of the technology of flight; reference material; and microfilms of the Hudson Strait Expedition fonds (1927-1928) and "The Bulletin" (Western Canada Airways, 1929-1937). Additionally, there is material on Tweddell's other research interests, notably aerial mapping and surveying.

This fonds contains material relating to the research work, students, faculty and administration of the College of Arts and Sciences, and its departments. These records generally contain correspondence, minutes, reports, and memoranda; they may also contain material relating to associated national or international organizations, research articles, and addresses.