They did not file flight plans, radio ahead or register their frequencies.

他们并没有提交飞行计划，无线电波或频率。

China is demanding aircraft flowing through the zone file flight plans and maintain radio contact.

中国要求流经这一区域的飞机报告飞行计划并保持无线电联系。

China said it would take defensive emergency measures against any aircraft that failed to file flight plans before entering the airspace.

中国称将采取防御紧急措施来针对任何进入这片领空前未提交飞行计划的飞机。