China began trial runs of its controversial M503 flight path on March 15, according to an announcement by Taiwan’s Civil Aeronautics Administration.
The flight path was criticized because as initially announced, it would run just 7.8 kilometers from the median line separating the two sides of the Taiwan Strait. The Taiwan government charged that Beijing was taking “unilateral” actions and failed to consult it concerning safety issues. China responded that the new route is necessary to ensure safety in its otherwise crowded airspace, but promised to move the route 11.1 kilometers to the west and only use it for one-way traffic north to south. In addition, the route will only go into regular use once guidance and navigation systems are proved reliable. Taiwan’s Mainland Affairs Council and Ministry of National Defense said that they were informed of the tests beforehand.