When visibility is less than 800m, the minimum criteria for takeoff and landing are expressed in _______ .
A.RVR
B.VIS
C.ceiling
D.wind speed direction and speed
正确答案是A
When visibility is less than 800m, the minimum criteria for takeoff and landing are expressed in _______ .
A.RVR
B.VIS
C.ceiling
D.wind speed direction and speed
正确答案是A