 The thinness of the wings required fuel tanks and landing gear to be placed in the fuselage, and the hydraulic cylinders driving the ailerons were limited to thickness in order to fit.The small, highly loaded wing resulted in an unacceptably high landing speed, even after adding both leading- and trailing-edge flaps.As a result, the aircraft designers developed a boundary layer control system, or BLCS, of high-pressure bleed air, which was blown over the trailing-edge flaps to lower landing speeds by more than and help make landing the airplane safer.