By the seat of one's pants
凭借直觉或本能行事，而非依靠计划或经验。
用于描述紧急或缺乏准备时的即兴应对。
英文释义
To do something without advance preparation.
例句
He flew the plane by the seat of his pants during the storm.
典故来源
源自早期航空术语，飞行员靠身体感受飞机震动来判断飞行状态，而非仪表。