The ERJs don't have leading edge slats so they installed vortilons helping out the ailerons at high angles of attack. The upper surface of the wing also has vortex generators on the surface as an added help. They work in a similar aerodynamic fashon as a stall fence. Hawker replaced the stall fence on the 800A with vortilons on the 800XP.. .. .Apparently vortilons originally were used by Douglas while developing the DC-9, they have found their way onto other bizjets like the Hawker 800XP and GIV. The 800XP uses one large one, GIV uses 4 on each wing.. .. .JT,. .. .Dont think the 1900 is a good example, the stabilons are there to improve the cg range from 4% to 40% mac, improved pitch stability, and positive recovery from deep stall.. .. .The tailets and the vortex generators near the wing fuse interface improved the directional stability and reduced stall speeds.. .. .Z