[robair]

Gday Kieran

In regards to your earlier comment:
"you'd get the most benefit from some dihedral in the main cross section (Like how my Stryker looks now!) This directs the air to spill up over the wingtips instead of mid-wing and reduces mid wing stall."

I have to disagree with your explanation of dihedral effect or more correctly "Spiral stability" which is the result of increasing dihedral, dihedral does not affect airflow over the wing as the relative airflows remain unchanged irrespective of dihedral angle. The key is noting the velocity vectors of the vertical component of lift above a wing, or "Centre of Pressure" and how that relates to the velocity vector from the Centre of Gravity, with zero dihedral the Pressure vectors are parallel to the Cof G vector, with dihedral the Pressure vectors are angled in towards the CofG. each time the aircraft banks the dihedral angle will induce a sideslip moment that will change the angle of attack and speed up the lower wing, as lift is a function of speed the low wing will now be generating more lift and thus roll back up to level. Happy to discuss this with you in greater detail and a diagram or two would also help. One other thing to note is that the more air you have spilling over the wingtips the more induced drag you will have. This is most certainly not ideal!!! Directing air to the tips will actually increase the likelihood of root stall and greatly increase your aircrafts stall speed. Many types of aircraft use "Wing Fences" to prevent airflow heading out to the tips to avoid this. I would also like to see the term "Tip Stall" removed from our vocabulary, the term has currency with rotary wings howver no real technical merit in regards to fixed wings.


Cheers
Rob Byrnes