You have to fly by the seat of your pants.

你必须靠你的裤子的座位飞行。

Just flying by the seat of your pants.

就是凭冲动行事。

So generally this expression is used in its full form, to fly by the seat of your pants.

所以通常这个表达是用它的完整形式，靠你的裤子的座位飞。

Sometimes you’ll get back and find that things have changed, so you’ll be flying by the seat of your pants for a while.

【fly】有时候你回过头来发现情况又变了，就暂时要摸着石子过河了。

I know you don't like to fly by the seat of your pants, but maybe she'll have some ideas about what she'd like to do.

我知道你不喜欢凭感觉行事，但也许她会对自己想做什么有一些想法。

" To fly by the seat of your pants" is another way of saying to be spontaneous, to have spontaneity, to decide without making plans in advance.

“随心所欲地飞行” 是另一种说法， 可以说是自发的、自发的、无需事先计划就可以做出决定。