I want to know the answer to the following question:
When did the design begin for the 12.8 centimeter FlaK?
All the background I'm provided with is that "In the late 1930s the 10.5 cm FlaK 38 appeared soon followed by the 39, this was designed primarily for static sites but had a mobile mounting and the unit had 220v 24 kW generators.". Is that enough to answer the question?