LilGreek

Yes, I am. I haven't used stock aerodynamics since the first few days of playing KSP

The slats do indeed help, but pretty much only as a counterbalance to the trailing edge flaps' downward pitching moments. Without the leading edge slats, this plane would not have the pitch authority to maintain controlled flight without drastically (and disproportionately) changing the elevator deflection limits. As far as the slot mechanics go, right now adding slots in any kind of airfoil does not seem to do anything. At the very least I thought adding a slot to the fowler flaps would un-stall the flap airfoils at what would otherwise be stalling conditions, but experimentation shows that the slot simply transfers the acting aerodynamic forces from the wing airfoil to the flap airfoil.

I have designed working fowler flaps and leading edge slats, like those commonly found on commercial airliners. Fowler flaps work by sliding outwards from the trailing edge of the airfoil while also deflecting downwards. Most other common flap designs simply change the camber of the airfoil, but fowler flaps do the same function in addition to increasing the chord of the airfoil. In some cases fowler flaps become slotted, which act to keep air flowing over the airfoils at high angles of attack and low airspeeds, at the cost of increased induced drag. It's not uncommon for commercial airliners to have double slotted fowler flaps. Slats function by pushing the leading edge of an airfoil forward and slightly downward. They essentially create a slot at the front of the airfoil that also helps keep air flowing over the airfoil at slower speeds, again at the cost of increased drag. Slats also produce nose-up pitching moments which help counteract the nose-down pitching moments caused by trailing edge flaps. This craft is equipped with single-slotted fowler flaps and leading edge slats. Deploying the flaps will cause the trailing edge flaps to slide outwards while also deflecting downward. Simultaneously, the leading edge slats will also slide outwards and deflect forward (the slat deflection is very slight). In my attached imgur gallery I have used Persistent Trails to illustrate the difference between takeoffs with these flaps at different settings (trials done with SAS enabled and no user input to flight controls), blue being flaps fully retracted and green being flaps fully deployed. Additionally, I have attached pictures of flap operation in-flight; first by demonstrating the difference between retraction and extension at a randomly given pitch angle, and then by holding the nose at 10 degrees while trying to maintain level flight (notice the few degrees of angle of attack differences and the increased speed for less lift with flaps retracted). This design functions a lot differently than F.A.R.'s flap system. I did side-by-side comparisons with the same airfoils on the same airplane and found the flaps to produce a lot more lift and change the aircraft's properties a lot further when simply using F.A.R.'s flap deflection system, even when the angle of deflection was less than with my hinge design. Design was troubling at first, because without reinforcement between the flaps, the airfoils would wobble uncontrollably as they deflected through regimes of high aerodynamic force. Please view my gallery and I shall update the thread with links to download and more information. I have given a name to the airplane: Fortitude! Currently version 1.33 This plane is capable of stable autopilot using MechJeb and F.A.R.'s dynamic control adjustments. I'll update this thread with reliable D.C.A. values as I find some. Without D.C.A., this airplane would wobble uncontrollably with the use of stock S.A.S. and MechJeb Smart A.S.S. So far I've learned that using a scaling velocity of 40 and a scaling altitude of 1000 works nicely for maneuvering approximately 1000m and below. Video of plane autolanding from final approach: Mods required: Unofficial B9 Aerospace REPACK {download} [Plane body & engine] Procedural Dynamics {download} [Airfoils, control surfaces] MechJeb {download} [Flight information, autopiloting] Magic Smoke Industries Infernal Robotics {download} [Flap design] Ferram Aerospace Research {download} [Aerodynamics, flight information] (Optional, but highly recommended) Find this project on cureforge here Download this airplane! Download this airplane!