Abstract: A releasing system for retaining a cover over an opening in a structure. A penetrating member connected to the protective cover is tapered at one end and has a notch just beyond the taper. A housing contains a spring latch made of bent steel strip. One end of the spring latch is firmly attached to the housing and the free end of the spring latch is located behind and partially covers an opening in the housing. The spring latch is positioned so that the tapered portion of said penetrating member will push the free end of the spring latch aside when the penetrating member is entering the housing, and the free end will fit into said notch when the penetrating member is essentially fully inserted into said housing. One end of a release cable is attached to the spring latch near its free end and when pulled with sufficient force will cause the free end of the spring latch to be pulled out of the notch releasing the penetrating member.