Just as new trees rise up from the loam of dead bark and leaves, Nancy Rubins’s two “Small Forest” installations reanimate the wings, fuselages, and propellers of junked airplanes. Jagged, yards-wide canopies of aluminum, plastic, and fiberglass spread out above stainless-steel trunks like mutants evolving from industrial deadfall. Rubins crosscuts the smooth curves and seamlessly joined metal surfaces demanded by the laws of aerodynamics to expose thin, underlying support braces shot through with weight-reducing circles and triangles. The overhead flux of the sculptures conjures many surprising associations: In Small Forest I, stiff hoses, fluted ducts, and ridged manifolds evoke the Medusa myth; elsewhere, myriad exhaust tubes and fuel lines writhe through angular conglomerations like the snake entwining Laocoön. But where that ancient sculpture supported its massive volume of marble through strategically placed struts and broad pedestals, Rubins’s aeronautical boneyard upends such venerable logic: Its weight is suspended in perpetual free fall by a taut geometric web of galvanized guy wires. It is to Rubins’s credit that these pieces, part of a body of work begun long before 9-11, overcome the anxiety generated by earthbound wreckage, letting us experience the sober joy of reclaiming what was once fallen.