If deployment of the landing gear doe not work during a hydraulic failure, the gear can be deployed by means of an auxiliary system. The Alternate Gear Down Handle (ALT LG Handle) unlocks the landing gear, which locks due to its own weight. Pulling the ALT GEAR handle supplies pneumatic pressure to open all LG doors, extend the landing gear and shut off the LG selector hydraulic valve. The LG/hook emergency pneumatic bottle is also used to lower the hook and contains sufficient pneumatic pressure for one LG extension and to hold the hook down. The bottle cannot be recharged in flight.
The model was created in Blender 2.81 for the Cycles engine, the textures and materials are PBR based with a scale as close to the real life one (.stl file supplied upon request). The model has been rigged with a simple Empty for easy animation.
I tried to keep all the materials packed within the .blend but if for some reason it is not here, you can find them on the Texture folder in the .zip file that accompanies this panel or if you still require it, don't hesitate in contacting me.