Berlin Tegel Airport eminent aerospace engineers, which included German rocket pioneer Wernher von Braun. In 1937, the rocket pioneers left Tegel in favour of the secret Peenemünde army research centre. During World War II, the area served once again as a military training area, mostly for Flak troops. It was destroyed in Allied air raids. Plans for converting the area into allotment gardens were shelved due to the Berlin Blockade, which began on 24 June 1948. In the ensuing US-led Berlin Airlift, it quickly turned out that Berlin's existing main airport at Tempelhof was not big enough to accommodate all relief aircraft. As
Airport city Airport city Airport city is the "inside the fence" airport area including the airport (terminals, apron, and runways) and on-airport businesses such as air cargo, logistics, offices, retail, and hotels. The airport city is at the core of the aerotropolis, a new urban form evolving around many major airports. The airport city model recognises that an airport can do more than perform its traditional aeronautical services, evolving new non-aeronautical commercial facilities, services and revenue streams. Airports are now routinely targeting non-aeronautical revenue streams amounting to 40–60% of their total revenues. Industry leaders and researchers share best practices on non-aeronautical revenues