More than half of the country's military aerodrome clearance zones have been affected by negligence over the past two decades, leading to nearly 100 plane accidents and the closure or relocation of about 10 military airfields, according to the General Staff Department of the Chinese People's Liberation Army（PLA）, Xinhua News Agency reported.

Aerodrome clearance refers to an area of protected airspace surrounding certain airfields, and includes restrictions such as those concerning the height of buildings, to ensure the safety of planes in the air. China’s rapid urbanization means that military aerodrome clearance has been affected by expanding cities incorporating military airfields.

The PLA statistics show that there are more than 1,000 "illegal" high-rises within military aerodrome clearance zones. Additionally, birds, objects and small planes are other major causes of accidents involving army planes, leading to security risks during military training.