5700千克以下飞机做商业运输运行需要通过哪一部法规审定？ Which regulatory approval should

5700千克以下飞机做商业运输运行需要通过哪一部法规审定？ Which regulatory approval should be get before the aircraft less than 5700kg do commercial transport?

A.135部 The 135 part

B.121部 The 121 part

C.142部 The 142 part

正确答案是A