The Beriev Be-12 Chayka (“Seagull”, NATO reporting name: Mail) is a Soviet turboprop-powered amphibious aircraft designed for anti-submarine and maritime patrol duties.
The Beriev Be-12 was a successor to the Beriev Be-6 flying boat, whose primary roles were as an anti-submarine and maritime patrol bomber aircraft. Though tracing its origins to the Be-6, the Be-12 inherited little more than the gull wing and twin oval tailfin configuration of the older aircraft. The Be-12 had turboprop engines, which gave it an improved speed and range over the Be-6. The Be-12 also had retractable landing gear, which enabled it to land on normal land runways, as well as water.
Source: Be-12 on Wiki