I have asked several questions on stack exchange, but my questions are often not understood. They seem a little too pedantic.
This is an actual question that I wrote on the aviation stack exchange site but could not post due to the 40 minute rule. How can I improve this question?
A brief review of light aircraft designs one is struck by the similar performance figures of aircraft that have similar wing areas and engine horsepower. For example aircraft with a 180 HP engine rarely can fly faster than 120 knots if they have fixed gear. With retractable gear an increase in 10-15 knots seems reasonable.
Stall speeds are proportional to wing area and can be reduced with high lift devices such as vortex generators, slats, flaps and so on.
How reliable it the process of designing and aircraft based on the lift equation for determining the stalling speed and an empirical formula for cruising speed as a function of engine power? Is using a sophisticated design program the only way to obtain useful results, or will an empirical method described be useful for preliminary design without being too misleading? There are several tools available for aircraft design but they need the user to enter more than 25 different parameters.
For reference [this article l]ists light aircraft cruise speeds.