What is the "A/B AUTO EXT" button for in a Falcon 7X? What is the "A/B AUTO EXT" button in the overhead panel of the Dassault Falcon 7X? I see it's in the Flight Control section but I don't know what is its purpose.



(sorry for low quality image)
It's the arming switch for Air Brake Auto Extend on landing.  The airplane has speed brakes (often called Flight Spoilers) the pilot can operate manually for glide path control.  This mode extends them automatically as lift dumpers after touchdown.