The propeller pitch numberrefrences the forward distance that the propeller would travel in one revolution in a perfect (theoretical) medium. A propeller with a pitch of 48 wolud travel 48 inches forward witin one revolution of the propeller, while a propeller with a pitch of 50 would travel forward 50 inches. The lower the pitch number, the better climb performance, and the higher the pitch, the farther/faster the plane travels. It's kind of like a car accelerating and climbing a hill in 1st or 2ond gear, as compared to the sluggish performance of starting off in 3rd or 4th gear. Better performance for starting and climbing in the lower gears, but your going to be traveling at a slower forward speed than with the car in the higher 3rd and 4th gears. I hope this heps out in making the propeller pitch numbers more clear.
Stan Bearup
