I dont know airline gear speeds but here are some fast gen av piston planes that I do know. Bonanza 154 knots, good!, T-34 only 112 knots. P 51 150 knots? , flaps can be 20 % at 275 knots. Spit IX with one of the best basic systems, 136 knots and flaps which are either up or down. P-51 has 5 notches of flaps including last at 50*!!!!!.