Airplane bath is a quick method of cleaning by taking a wet wash cloth under each wing and the tail; meaning the armpits and the crotch region1.
飞机洗澡法是一种迅速洗澡办法,即用湿毛巾在两腋和胯部地区擦一下完事。
Example:
Dude 1: Hey, are you going out with us tonight?
Dude 2: Yeah, man. When?
Dude 1: In about five minutes.
Dude 2: Oh shit! I'll just take an airplane bath and go!
甲:嘿,你今晚和大家一块出去吗?
乙:当然了。什么时候啊?
甲:大约五分钟后。
乙:什么!我去飞机洗澡一下就走!