1. explain or complete quickly
fly through instructions/plans/tasks
To 'fly through', can literally mean to fly by plane or helicopter through a place. The expression 'to fly through' something means to finish or complete something quickly. You might 'fly through' reading a book or 'fly through' a task or project. If you 'fly through' a place, it can mean you travelled through it quickly without spending a lot of time there. You will hear this used in professional and social contexts. Note also that the noun, a 'fly-through', relates to an overview or short simulation of something, and is generally used with regards to VR simulations.