The solution involves an external element which contains an element free to rotate within it. The external element can be fixed to a structure, for example the cabin of an aircraft, which under certain conditions can assume any orientation in space. The internal element, on the other hand, thanks to a suitably positioned concentrated mass, tends to assume a given orientation depending on the earth's gravitational attraction.
LDO-H7412
Displays the attitude of an aircraft relative to a fixed direction in space