ALT Gear Handle? in Wishlist Posted Friday at 01:21 PM 19 hours ago, Bouli306 said: Yes, nitrogen is actually introduced in the hydraulic lines via the actuators. That is why you can expect a hydraulic B failure soon after alternate gear extension. That is why the NWS is not functional after alternate LDG extension. Go learn about Landing Gear Hydraulic isolation valve, how it works and its relation to the alt gear extension. That will answer why NWS does not work and why no air is introduce to the hydraulics if all alt gear procedures are followed and the system is working as it should. The most common way air is introduced to system B is when people press that reset button at the same time the pull the handle.