Autothrust Blue
Welcome aboard the Washington State Ferries
"Roger, Buzzsaw 5105, hold at Rome as published, expect further clearance next week."You sure about that?
"Unable Center/Approach, we're a broke down Maddog."
It falls under the "can, strongly prefer not to" category.
Especially when the outstation is a maintenance base and they've got the damn part, you've only got one FMS CDU, it takes 20 minutes to fix it, and much of the other butthurt that comes with an inoperative CDU (performance, etc.) can be solved by having an operative CDU.