Yes, my Kitlog has been inactive for a while but I am ready to get going. Since my aircraft involves some extensive modifications to an existing design, the engineering work behind those modifications are the starting point. My aircraft has to be LSA compliant but the current criteria for that compliance was driving some areas of the design to excess. The worst part was the amount of wing that is required to meet the 45 kts stall speed in clean configuration (the rest of the world gets to use flaps!). All of that oversized wing area (around 125 sq ft) drives the requirement for more area in the horizontal and vertical tails.
The FAA has finally released the long overdue draft for the revised LSA regulation and that troublesome stall speed requirement will be improved. The draft puts it at 54 kts which is a nice improvement but still in the clean configuration. The math brings the wing area required down to around 90 sq ft and that eases the need for excessive tail sizing. The span will be a little more than the stock wings 25 ½ feet at 27 feet and the root chord gets increased to 44” from 36”. Those changes provide about 14 sq ft to the stock wing and the actual design of the wing changes considerably.
The Cruiser had a solid core, constant chord wing while my aircraft will have a slightly tapered wing that is hollow and can contain fuel as well as other items such as flight control components, The tail size is of course better and the solid core standard tail components are now acceptable to use. The only significant changes are to the Vertical tail which is moved a bit aft so that the elevator and rudder no longer overlap requiring large cutouts in the elevator. Additionally, there is a ventral strake used with the lower end of the rudder being extended downwards to match. These changes provide the vertical tail with both more moment arm and increased area. An important factor here is having more rudder that will not be blanked by the horizontal tail in a stall for better controllability. It does require
