My Thanks to the further respondents, very grateful to you for your time and knowledge. Wherever its relevant and applicable I incorporate fullsize features into my jet models. My 2 Hawks already flying have all the wing vortex generators, set at the correct angle, wing fences and the gap in the flap vane. The result is a fine flying machine with excellent handling, no sudden departures at or near the stall, both at low speed, 1 G, in the approach config (flaps 40) and clean when pulling max G and what is probably past the buffet (when I can see the pitch rate reduce with increasing stab. angle.
One final question. I understand the gap in the flap vane on early Hawks (pre SMURF) was incorporated to counter the severe nose down pitch as flaps were extended which is reported in some media, (eg World Air Power Journal,) as due to strong downwash from the powerful flaps stalling the stab.
The flap vane gap is outboard of the stab. so how exactly was the flap vane gap effective in reducing downwash over the stab ? Again, just very curious, anyone able to put me out of my misery ??
Last edited by RetiredBA/BY; 4th Mar 2013 at 15:16.