Device for attaching one part to another

The mounting system for a panel (14) in an aircraft comprises a plug (20), to which the panel is attached by a swiveling arm (22). The plug has a central bore (26), through which a bolt (30) into a plate (48) mounted on the aircraft. This is locked in place by a parallelogram-shaped locking plate (46) which can rotate and is biased against the nut (44) by a spring (58). A release plate (60) is mounted between the plug and the base of the mounting plate.