Artist's impression of Bell Aerospace Cold Thrust Augmentation (CTA) V/STOL proposal.
Bell Aerospace V/STOL proposal uses the most interesting wing technology. Called "cold thrust augmentation" (CTA) minimum drag and maximum lift are produced by ducting air downward through slots in the wing. About 50 percent of engine air is bypassed through wing nozzles located in spanwise slots in the wings. The wings look like an accordion at low speed but flatten out during cruise.
Source: "Medium-Range STOLs Get Set" Popular Science December 1973
Bell Aerospace V/STOL proposal uses the most interesting wing technology. Called "cold thrust augmentation" (CTA) minimum drag and maximum lift are produced by ducting air downward through slots in the wing. About 50 percent of engine air is bypassed through wing nozzles located in spanwise slots in the wings. The wings look like an accordion at low speed but flatten out during cruise.
Source: "Medium-Range STOLs Get Set" Popular Science December 1973