一个朋友想来美国学开飞机大约一年时间,如果申请f1签证,这种F1也是5年的吗?
-One to five years, depends how long he plans to study in US (I-20 will tell it).
那学完飞机后一两年内再入美国是用f1还是原来的b1?
-B-1 after he completes the study program.
申请了f1后b1会作废吗?
-No. The F-1 visa will not affect the B-1 visa validity.
除了学飞机这一年,以后如果再来美国旅游商务需要重新申请b1吗
-No unless the B-1 visa expires.