§ 2.5 named the grant: under § 107.21, in an in-flight emergency requiring immediate action, the remote pilot in command may deviate from any rule of this part to the extent necessary to meet that emergency. The striking half of that sentence is the permission — leave to set aside any Part 107 rule at all. The half that decides real cases is the limit, and it is the one worth spending a section on.

There are two hedges and they bind at different moments. The first is the doorway: the authority applies only in an in-flight emergency requiring immediate action — not an inconvenience, not a tight spot you could see coming, but a genuine emergency unfolding in the air. The second is the size of the departure: even inside a real emergency you may deviate only to the extent necessary to meet it, which is the minimum the situation demands and no more. What falls outside is easier to name than to admit in the moment — the seconds after the danger has passed, the altitude you keep because you are already up there, the second run at a shot the deviation happened to make possible. Go further than the emergency actually requires and the excess is judged on its own terms, unprotected, as though you had simply broken the rule.

It also comes with accountability after the fact. Under § 107.21(b), a remote pilot in command who deviates under this authority must, upon request of the Administrator, send a written report of that deviation to the Administrator. You are not required to file unprompted — but if the FAA asks, you must account for what you did and why. That pairing is the whole design: act freely in the moment to prevent harm, and be ready to explain it afterward. And it lands where the chapter on crews began — the same remote pilot in command who holds final authority over the flight also holds this emergency authority, and answers for how it was used.