A system for detecting cargo movement inside a cargo compartment of a craft, such as a plane or vehicle. The cargo is mounted on pallets that in turn are transported within the cargo compartment on rails end kept in place by latch assemblies. An arm assembly is mounted to a fixed convenient location inside the compartment at its distal end attached to a suitable position on the cargo being monitored. At least two parallel arms are pivotally mounted to the fixed position at the distal end. One of the arms to pivotally mounted indirectly through plate members. The plate member pivotally mounted to the fixed end includes a magnetic element that moves in physical proximity to a magnetic field sensor. If the separation exceeds a predetermined magnitude, the sensor generates an output signal that is transmitted to the pilot or driver for the necessary measures to be taken.