A report by Der Spiegel detailed on Friday concerns on the part of the German Defense Ministry that China has been hiring former NATO and Bundeswehr pilots who might disclose to Chinese authorities classified information and confidential operational tactics. 

Without specifying the exact number of hired pilots, the report states, quoting the German Defense Ministry, that "China is attempting, via external agencies, to recruit former NATO pilots ... former German Bundeswehr pilots ... A significant danger that not just basic flight proficiency will be imparted, but that relevant tactics, techniques, and procedures will be manifested."

According to the report, the Chinese Air Force recruited several retired German military pilots through the Lode-Tech shell company of Chinese national businessman Su Bin.

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In 2016, Su Bin was sentenced to four years in jail in the US for stealing "cutting-edge" US military secrets. 

In 2017, he was deported to China in exchange for a Canadian couple that was suspected of espionage by Chinese authorities. 

Spiegel says that the former German pilots that were hired by China's Air Force are allegedly taking part in military drills at the Qiqihar military airfield near the Russian border.

The German government believes that some of the pilots may have already given away classified information about confidential operational tactics and practiced various attack scenarios, including an attack on Taiwan.

The report further states that the salaries of former German pilots in China are far higher than the pension they receive after reaching the age of 41. 

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