Originally Posted by
flywilly
... Back in the '90s, an Australian pattern flier named Peter Goldsmith (now living in the US) did some wind tunnel testing and discovered that fixed gear (streamlined & with wheel pants) had significantly less aerodynamic drag than retracted retracts. The only way retracts provide an aerodynamic advantage is if there are door covers for the retract wells that are air tight. ....
Besides, drag reduction is not a design goal. Just look at current pattern planes. You want it light enough to fly slowly, powerful enough to continue at the same speed going up, and draggy enough to keep it slow coming down.