FernandoPDA Posted October 2, 2017 Posted October 2, 2017 Hello: I have a Savannah from the year 2006. Recently upgrade to VGs. To maintain level flight I need to pull the lever backwards despite using maximum trim What is the solution? Thanks
FernandoPDA Posted October 3, 2017 Author Posted October 3, 2017 Weight&balance are OK Could be engine incidence? Could be flaperons regulación? Thanks
dan tonner Posted October 5, 2017 Posted October 5, 2017 If the aircraft flew properly without the VGs and with slats, the issue appears related to the altered lift characteristics and/or airflow changes resulting from removal of the slats (I have assumed the slats were removed) and the addition of VGs. JG (John Gilpin) - an active contributor to this group - was a pioneer with this modification to the Savannah aircraft. I suggest you address an inquiry directly to him. You may have seen these articles - certainly a good place to start... http://www.stolspeed.com/slats-v-s-vgs; http://www.stolspeed.com/id/26; StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft (the latter two links connect to JG) Wish I could offer more. Fly safely. CanadaDan 1
JG3 Posted October 5, 2017 Posted October 5, 2017 If the aircraft flew properly without the VGs and with slats, the issue appears related to the altered lift characteristics and/or airflow changes resulting from removal of the slats (I have assumed the slats were removed) and the addition of VGs.JG (John Gilpin) - an active contributor to this group - was a pioneer with this modification to the Savannah aircraft. I suggest you address an inquiry directly to him. You may have seen these articles - certainly a good place to start... http://www.stolspeed.com/slats-v-s-vgs; http://www.stolspeed.com/id/26; StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft (the latter two links connect to JG) Wish I could offer more. Fly safely. CanadaDan I'm already in direct contact with Fernando, trying to figure what's happening here. Never heard of similar results in any of the many conversions done.... JG
IBob Posted October 5, 2017 Posted October 5, 2017 I'm already in direct contact with Fernando, trying to figure what's happening here. Never heard of similar results in any of the many conversions done....JG We're interested to know what you find, if you're able to share it... 1
FernandoPDA Posted October 6, 2017 Author Posted October 6, 2017 I am in contact with John Gilpin. I think the problem is the level of flaps. I ´ll try to check it in next days.
rollerball Posted October 7, 2017 Posted October 7, 2017 Is it the stolspeed conversion that retains the original wing cord and profile with just the slats cut off or the 'official' one that has a changed profile and slightly larger wing area with a completely new leading edge? 1
marcov Posted October 9, 2017 Posted October 9, 2017 As a textbook warrior, I would expect that removing slats and installing VG's may move the centre of lift of the wing slightly rearwards. I would start with basics. recheck CG, as it may have been near forward limit which worked OK with slats, but now with CL moved rear, may be out of CG range. As you suggested other culprits could be flap setting, elevator trim/incidence setting or engine incidence. Running out of elevator authority at low speeds could be serious. Good luck and please tell us what you discover.
FernandoPDA Posted November 12, 2017 Author Posted November 12, 2017 Today the weather was good and we were able to fly the Savannah VG. Previously, we had set the flaperons with the ICP tool. The change in the plane is great, now it flies perfectly level. Many thanks to all, especially to John Gilpin. 5
marcov Posted November 12, 2017 Posted November 12, 2017 Today the weather was good and we were able to fly the Savannah VG.Previously, we had set the flaperons with the ICP tool. The change in the plane is great, now it flies perfectly level. Many thanks to all, especially to John Gilpin. Hi, Id be very interested to discover what the problem was and how it was solved. Thank you in advance. Cheers
JG3 Posted November 13, 2017 Posted November 13, 2017 Hi, Id be very interested to discover what the problem was and how it was solved. Thank you in advance. Cheers The flaperons were set incorrectly, with some downward droop. When he got the ICP jig to set them properly, all came good.
marcov Posted November 13, 2017 Posted November 13, 2017 The flaperons were set incorrectly, with some downward droop. When he got the ICP jig to set them properly, all came good. Great news. Thanks for letting me know.
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