Effect of Retrofitted Winglets on 767 Handling
I recently posted the same thread on Airliners.net, so apologies if anyone's reading this twice, but I wanted to get the largest possible amount of opinions.
I'm on an internship (for my final year thesis) at an MRO doing a study of blended winglets, in particular, those installed onto the 767-300ER.
I am interested to hear some views from current Flight Crew on any effects the installation of winglets has on the handling characteristics of the plane.
I have already spoken to a UA test pilot who was recently performing the post-mod test flight on one of their a/c and he suggested that there is little noticeable difference to the way the a/c handles following winglet installation. He did however admit that he wasn't the best person for me to ask as he does not exclusively fly the 767s.
I'm thinking that by adding these devices - they're really quite substantial on the 767-300 - there could be an increase to the dihedral effect of the wing adding some extra roll damping?
As the effective aspect ratio is increased, the Mean Aerodynamic Chord is perhaps shifted towards the tips slightly? Combining that with the presumed aftwards shift of the longitudinal centre of gravity due to the winglet's weight, are there any performance implications upon take-off/landing which are at all noticeable?
As pointed out to me, no further type-rating is required for pilots to fly these modified 767, but I just find it slightly difficult to believe that these devices go completely unnoticed from the controls. I'm certainly not a pilot so any views from current flight crew would be welcome!