Hello allWhat do these two technical terms mean? Are they the same thing? thanks

Best RATE of climb is the speed at which you will get the best climb out of the VSI. At higher speeds you may actually produce more lift for a given amount of thrust then at a slower speed. Once you reach a point in the lift curve where your drag gets really big, going slow will not give you a better RATE of climb. Best Angle of climb means just that, your climb ANGLE is steeper over a given distance, but its not necessarily going to be your best rate. Best angle of climb is usaully a bit slower Indicated airspeed than best rate. Now if your in alightly loaded clean F-16, then your best rate AND angle is probably straight up! Its not totally intuitive, but they are somewhat different, hope this helps.Hornit

Just to amplify what Hornit said:Best Rate of Climb (Vy) is the speed that will get you up in the shortest amount of time. Good for putting some distance between you and Mother Earth as quickly as possible.Best Angle of Climb (Vx) is the speed that will get you up in the shortest amount of distance. Good for clearing those trees at the end of the runway.

thanks for extendsive explanation. So I concluded that if I fly at the Best Angle of Climb (VX) that means I'm puching the limits of my aircraft, with full throttle combine with the most possible pitchup angle without losing the airspeed. But in Best Rate of Climb (Vy) is the most economical and efficien climb.

The way that I remember it is that Vy is time, and Vx is distance.Let's say that you want to climb from sea level to 5000 feet above ground level (AGL). If you want to do it in the shortest amount of time, and don't care about how many miles it will take you to get there, then you fly Vy. If you want to climb to 5000 feet in the shortest distance of the ground say for obstacle clearance, then you would use Vx as your reference.Just as a side note, Vx and Vy are not static numbers, they change with altitude. As you climb Vy decreases and Vx increases. Tim13

Good answers all. But what about Vyse, and Vxse. Anyone want to cover that for the pilot who is asking? I wanted to be cute, and say Best Rate is Vy, and Best Angle is Vx, but maybe this is just as good.