The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants.
HLA-B39 (B39) is an HLA-B serotype.
The Metropolitan Transportation Authority (MTA) operates a number of bus routes in Brooklyn, New York, United States; one minor route is privately operated under a city franchise.
The Mark 39 nuclear bomb and W39 nuclear warhead were versions of an American thermonuclear weapon, which were in service from 1957 to 1966.
B-39 was a Project 641 diesel-electric attack submarine of the Soviet Navy.