Why does Germany is not so advance in aircraft development? I tried to see what countries are the most advance in developing aircraft. I found that Germany is not so advanced (CMMIW). Indeed, there is Dornier there beside has share in AirBus. I don't know whether they are the biggest share holder or not in AirBus.

In another side, among of the G8 countries, US is the leader. They have lot of aircraft industries. Boeing, Lockheed Martin, GulfStream, and many other. Canada has Bombardier. British has BAe with their RJ70, RJ100, so do Roll Royce with their power plant. Italy has Avanti and Augusta Westland, beside small aircraft industries. France with Dassault, Mirage, also joint venture AirBus, and some more small industries. Russia has Sukhoi, Ilyushin, Tupelov, Mikoyan, Beriev, and there are more. And Japan has Mitsubishi, Kawasaki, and Honda, now they are massively develop and  research aircraft, both for civil and military. But Germany is look like not so aggressively take part in this technology like they do in another part. Even China is now growing. With Comac, they has now C919, and now with Russia is developing C929 which will emphasizes their presence in aviation manufacture. ABC, AirBus, Boeing, and Comac are considered as the biggest manufacturer, leaving Germany behind. Is any reason why? Germans probably can explain.
May i suggest, you read the wikipedia artikle "History of Airbus".History of Airbus
There are also other big aerospace companies in germany, like MTU, DIEHL and LIEBHERR just to name a few. These companies don´t build their own planes, but manufacture major components for the aerospace industrie.