A broken uplock
cable can result in a gear-up landing, but it's an easy check on the ground.
During its investigation the NTSB determined the aircraft underwent extensive maintenance that included the removal, replacement and visual inspection of the left and right main landing gear uplock
It never completely engaged the uplock
so the gear fell back down.
My favorite example is a main landing gear uplock
bracket, a piece of stamped and drilled aluminum sheet.
1, which is a comparison between determinant assembly and monolithic approaches to the 767 main landing gear door uplock
This AD requires the installation of modified roller sub-assemblies in both the main landing gear (MLG) door lock and the MLG uplock
When not in use, the sinking platform is held up by four 10-inch-bore Vickers uplock
cylinders that take the load off the main cylinder.
assembly is spring loaded to the locked position to relieve hydraulic system pressure.
After consulting NATOPS, my two copilots, my flight engineer and I determined the nose gear was released from its uplock