A Royal Canadian Navy (RCN) Sikorsky H04S helicopter flies over Miami, Florida, to join in naval exercises off Key West.

Entering limited service during the Second World War, helicopters emerged as a potent anti-submarine weapon in subsequent years. The H04S - known more widely by its "S-55" model number - was the first helicopter capable of carrying the large loads necessary for anti-submarine warfare, which included sensors, the crew to operate sensors, and weapons. The RCN also used these helicopters to test the "Bear trap" system that allowed large helicopters like the Sea King to land on destroyers and other anti-submarine vessels.

George Metcalf Archival Collection
CWM 19900076-972