ASG Hydraulic Hand Pumps

These pumps have proven very reliable, but just in case, Erie
Aviation, Inc. has factory-trained technicians, and is set up
with complete repair facilities including a dedicated test rig for
them. Whatever the problem, we can have a pump quickly repaired
and recertified for you. We also stock complete pumps, all the necessary repair parts and the handles right here, so weve got you covered

More precisely, one pump provides the backup. It is used to
manually charge the Yellow hydraulic system that operates these
doors. The other is used to manually fill the reservoirs of three
hydraulic systems: Yellow, Green and Blue.The pumps are installed
in the un-pressurized belly fairing of the aircraft, one on each side
just behind the main landing gear, so obviously they are only used
when the aircraft is on the ground. Each pump comes with a long
operating handle.

Normally an electrical pump operates the forward and aft cargo
doors, but if there is no electrical power or if that pump fails, these
ASG pumps provide the backup.