IMHO...using flaps on the Flash or Lightening is a wash, due to the extra drag created by the spoiler part of this type of flap. Lift is created by the faster airflow over the top of the wing more than the relative wind across the bottom of the wing. Using the flaps on take off for a Flash/Lightening, the spoiler is reducing your lift for take off.. Full scale planes/jets never take off with any system or flight control that deters lift. The Flash/Lightening is using a spoiler when flaps are extended. This would be like a full scale jet taking off with spoilers extended. Flaps purpose is to: reduce take off roll, increase weight off of a given runway distance, and when critical, flaps may not be used on take off due to second stage climb of a jet with engine loss. Due to our jets being over powered, you won't notice the benefits or disadvantages of flaps for take off. Our power on r/c jets is mostly 1:1, while a full scale jet thrust to weight is 1:3. This means the power is about a third of the max take off weight. Flaps then become a necessary flight control to provide more lift to carry more weight off of a shorter runway at a slower indicated air speed and reduced tire speeds.