Abstract: A variable section exhaust nozzle for jet engines which has two sets of fs at the edge of the nozzle opening, one set spanning the spaces between the flaps of the other set. Both sets of flaps are hinged to the nozzle on tangential axes. Fluid-operated jacks are serially connected to define a polygon around and outwardly of the flaps. Levers connect the jacks to the outer set of flaps so that radial expansion or contraction of the polygon, by actuation of the jacks, causes the outer set of flaps to swing outwardly or inwardly to thereby vary the effective area of the nozzle opening. The flaps of the inner set are held outwardly against the outer flaps by the pressure of gases issuing from the nozzle. In another embodiment two additional sets of flaps are hinged to the free edges of the first set and additional fluid-operated jacks are provided for them to thus increase the range of nozzle opening adjustments.