Pneumatically powered surgical cutting and fastening instrument with manually operated retraction apparatus

A surgical instrument comprising:

• a handle assembly;
• a closure drive supported by said handle assembly and configured to generate a closing motion and an opening motion;
• a pneumatically powered drive system supported by said handle assembly and being configured to selectively generate a firing motion and a retraction motion;
• an elongate shaft assembly coupled to said handle assembly and communicating with said closure drive to transfer said opening and closing motions and further communicating with said pneumatically powered drive system to transfer said firing and retraction motions;
• an end effector coupled to said elongate shaft assembly, said end effector comprising:
• an elongate channel sized to receive a staple cartridge therein;
• an anvil pivotally coupled to said elongate channel and being pivotally responsive to said open and closing motions from said elongate shaft assembly;
• and
• a firing mechanism operably supported within one of said elongate channel and the staple cartridge and being movable from an unactuated position to an actuated position in response to an application of said firing motion from said pneumatically powered drive system and being movable from said actuated position to said unactuated position in response to another application of said retraction motion from said pneumatically powered drive system and wherein said surgical instrument further comprises:
• a retraction member communicating with said pneumatically powered drive system to enable a manually generated retraction motion to be applied thereto to manually move the firing mechanism in a proximal direction from the actuated position to the unactuated position.