A latch mechanism comprising, a hook-handle assembly including a hook member , a handle , and a linkage arrangement coupled between the hook member and handle , the handle adapted to control motion of the hook member when unlocking and locking the latch mechanism ; a clevis having a hook-end receiver and a coupler portion spaced apart from the hook-end receiver to at least partially define an opening therebetween, the hook-end receiver configured to engage with a hook end of the hook member as the handle moves from an open position extending away from the clevis toward a closed position extending toward the clevis ; wherein said latch mechanism further comprises a clevis-sensing lock carried on the handle , the clevis-sensing lock including a block coupled to the handle , a lock cylinder received in the block , a tumbler arrangement coupled between the lock cylinder and the block and configured to control rotation of the lock cylinder relative to the block , and an interference member coupled to the lock cylinder to rotate with the lock cylinder relative to the block , the interference member is configured to pass through the opening of the clevis in an unlocked position and engage an underside of the clevis and to block movement of the handle relative to the clevis in a locked position, the lock cylinder configured to control rotation of the interference member ; and a device having a head , a shaft coupled to the head , and a protrusion extending outward from the shaft , the shaft configured to be received in the lock cylinder to engage with the tumbler arrangement to allow rotation of the lock cylinder , the protrusion configured to engage with the handle to trap the shaft within the lock cylinder when the lock cylinder is in the unlocked position, and the head configured to extend away from the handle to provide an indication of an unlocked state of the clevis-sensing flock ; wherein the clevis is configured to receive at least the interference member carried on the clevis-sensing lock and to allow rotation of the lock cylinder to the locked position when the interference member is received through the clevis . a clevis-sensing lock carried on the handle , the clevis-sensing lock including a block coupled to the handle , a lock cylinder received in the block , a tumbler arrangement coupled between the lock cylinder and the block and configured to control rotation of the lock cylinder relative to the block , and an interference member coupled to the lock cylinder to rotate with the lock cylinder relative to the block , the interference member is configured to pass through the opening of the clevis in an unlocked position and engage an underside of the clevis and to block movement of the handle relative to the clevis in a locked position, the lock cylinder configured to control rotation of the interference member ; and a device having a head , a shaft coupled to the head , and a protrusion extending outward from the shaft , the shaft configured to be received in the lock cylinder to engage with the tumbler arrangement to allow rotation of the lock cylinder , the protrusion configured to engage with the handle to trap the shaft within the lock cylinder when the lock cylinder is in the unlocked position, and the head configured to extend away from the handle to provide an indication of an unlocked state of the clevis-sensing flock ; wherein the clevis is configured to receive at least the interference member carried on the clevis-sensing lock and to allow rotation of the lock cylinder to the locked position when the interference member is received through the clevis . <EOS>