While you're correct that the 170 can not be considered a STOL, it's not due to the lift/drag ratio that the L-19 has an advantage. Cessna's own literature regarding the Model 305 speaks of the takeoff power available from the 0-470-11 or 0-470-15 engine, which is capable of 213 hp for takeoff, to quote: "This 213 hp available for takeoff provides unusually good short field performance under adverse conditions", meaning usually, max gross weight and a rough field with near obstacles at the departure end. When you compare the wing loading and power loading figures for the L-19 and 170, you'll see that the wing loading figures are virtually the same (within 0.5 lb), where the power loading is grossly in favor of the BirdDog, with over 3 lb/hp. advantage. Add the larger diameter prop (90 inches for the L-19 vs 72 for the 170) plus the fact that the fixed pitch props on the 'Dog were lower pitch than the 170's and that later models even had constant speed props, their acceleration and pulling power on takeoff gave them the distinct advantage to get off the ground and climb out more quickly. Drag difference between the models at speeds of 50-60 mph would have to be considered negligible, IMO.


If you want to compare the L-5, it has a max gross wt almost the same as the 170 (2250 vs 2200 lb) with less wing area and a better power loading by 1 lb/hp. but the airfoil of the L-5 was a flat-bottom NACA 4412 with leading edge slats. It could out-lift the semisymmetric wing of the 170/L-19 (NACA 2412), which gave it its STOL capability, which is not quite as good as the L-19's; again, I believe, due to the superior power-to-weight of the BirdDog.

It's really all academic; I haven't yet been able to con myself a ride in the closest local BirdDog, but I have seen him put it through its paces, and it is a sight.