C919-100ER.国航首架C919‑100ER延程型，注册号B‑919X。字母X寓意无限潜能，身披五星红旗入列国航机队，国产大飞机开启载旗航空的云端征程。 Air China’s first COMAC C919‑100ER, registration B‑919X. The letter X symbolizes unlimited potential. Carrying the Chinese national flag, this home‑grown jet embarks on its journey with China’s flag‑carrier airline.中国民航 中国商飞 飞友 民航客机