This medal commemorates the service of the Portuguese Air Force's Search and Rescue Squadron (Esquadra de Busca e Salvamento) based at Lajes Air Base (Base Aérea 4) in the Azores between 1947 and 1960. 

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Key Details of the Medal:

• Aviation History: The aircraft depicted is the Boeing SB-17G Flying Fortress, a specialized search and rescue (SAR) variant of the famous WWII heavy bomber.

• The Unit: In 1947, Portugal's Search and Rescue Squadron 41 (Esquadra 41) began operations from Lajes. This squadron was vital for covering the "Azores Gap," a massive section of the North Atlantic where SAR operations were critical for transatlantic flights.

• The Aircraft (SB-17G): Between 1947 and 1960, the Portuguese Air Force operated five of these aircraft. The "SB" designation stands for "Search-Rescue" (post-1948). These planes were modified to carry an air-droppable Higgins A-1 lifeboat under the fuselage to aid survivors at sea.

• Significance of the Dates: The dates 1947–1960 mark the period during which these specific B-17 variants were the backbone of Portuguese SAR operations in the Atlantic before being replaced by newer aircraft like the Grumman HU-16 Albatross.