Safety locking device having a tilting hook

A locking device comprising a box mounted on a first structure, a primary latch implemented in the form of a hook cantilevered out from a tilt axis carried by said box to enable the hook to tilt between an open position and a closed position in which said hook supports a first catch member mounted on a second structure to be locked with said first structure, and a retractable locking member disposed to oppose tilting of the hook when said hook is in its closed position by a locking portion of said hook bearing directly against said locking member, wherein the locking device further comprises a secondary latch adjacent to the primary latch and made in the form of a member that is slidably mounted in said box to slide between a retracted, open position and an extended, closed position in which said sliding member is in the direct vicinity of an associated second catch member, said second catch member being mounted on said second structure adjacent to said first catch member.