B738 LE Flaps&Slats ALT EXTENSION
Does anybody know where to find any guidance on the time it takes to extend the LE devices using the ALT extension switch, as directed by the Trailing Edge Flaps Up Landing NNC?
I had this scenario in the sim and after momentarily moving the switch to the down position I continued to monitor the LE annunciator panel for a good 10 seconds and nothing happened. Consequently we configured for an ALL FLAPS UP LANDING however the LE devices had eventually moved to the full ext position and we obviously missed it.
I couldn't find any reference to the time it takes for the LE devices to extend in this scenario. Any thoughts?