Not sure if this was covered as the thread is so long.the 1900's gear has 3 lines to each leg, 2 down 1 up, the 2nd downline is attached to the manual pump. the standard procedure for gear up is if NLG is unlocked land gear down if one MLG is unlocked land gear up to avoid digging in a wing. The gear is held in the up position by hydraulic pressure augmented with the accumulator. Landing gear is held in the down position by overcentre on the leg braces, and internal locking pins in the actuators. Motor shutoff occurs in the gear up position by a pressure switch that actuates @ approx 2775, and will cycle on at approx 2320, and in the down position by all 3 downlock mechanisms in series switches off the motor the gear motor will run until all gear are down/locked or by a 16 sec timer. Gear indication come from downlock mechanism/wheelwell switches and overcenter switches on the drag braces. If I missed anything please feel free to point it out. Flightsafety manual pg 15-4 1994 edition