用：I've never taken the plane before.
I'd never taken the plane before.是过去完成时.过去完成时用于发生在过去的过去的动作中,而且用过去完成时的句子中常会出现以下时间短语：before 1998(一过去年份/时间,或过去发生的动作),by the end of sth.等.例如：
I'd learnt 6,000 English words by the end of last semester.
The train had left the station before they arrived.
由于你是此刻和坐在你旁边的人说这一句话,所以用现在完成时就可以了.如果你是在过去和那人说这话,就该用I'd never taken.