Berlin Tegel Airport used the airport as a diversion airfield before. Initially, all British Airways services from Tegel—with the exception of the daily non-stop service to London Heathrow—continued to be operated by BAC One-Eleven 500s. The daily London–Heathrow non-stop was operated with Hawker Siddeley Trident 2E/3B equipment based at that airport until the end of the 1975 summer season. (It subsequently reverted to a One-Eleven 500 operation.) From 1983, British Airways began updating its Berlin fleet. This entailed phasing out the ageing One-Elevens, which were replaced with new Boeing 737-200 Adv. During the second half of the 1980s, British Airways augmented its Berlin
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