Drop-tank development followed a competitive path rather than a single-country invention story. Germany had work under way, but Britain reached an operational solution first while trying to extend aircraft such as the Spitfire. The United States then pushed the idea into mass production. A late-war German paper drop tank still carried its own fuel pump and remained relatively expensive, showing how the same concept could differ sharply in manufacturability and scale.
Notable Point · 2:44:02-2:45:12
From operational drop tanks to mass production
Britain reached an operational drop-tank solution early, the United States mass-produced the idea, and a late German paper tank remained comparatively elaborate and expensive.