"Angular momentum is what it's called," Rich nodded. "Another ration of complicated mathematics if you want to see the science at it. Has to do with rate and ratio of your turn, speed, altitude, and a lot of other things that I'd have to look up for you. Tie a string around a rock, and give the whole thing a twirl. Faster you spin the rock, harder it pulls on the string.
Richard had been flying one-handed, casually tracking along behind Arcturus, smiling as the young flier began to learn how to use a light touch on the stick, considering the best way to improve the dirt track from his property into Everdale. When Arcturus began what was for him a speed run, Rich subtly pulled up closer behind to keep a closer eye on his charge. This was frequently the time when it happened. And there it was.
Pulling up so they were almost knee-to-knee, he spoke softly. "Well, young sir, I would wager you've just had an epiphany moment. Learned something about your broom and yourself at the same time. Saw you look down and lose your mojo. Happens to all of us who race, sooner or later, from one thing or another. You'll get over it, or learn that racing isn't for you. Also one of the worst panic stops I've seen in a long time. Try that with something like the Nimbus and you'll be over the front end in a heartbeat. Watch and learn..."
Using all of the acceleration of Miss Susan, in just a few second Richard was a few hundred yards from where Arcturus waited. He pulled up into a vertical climb, pulled out of that inverted and rolled upright, a classic immelmann turn. He used the gain in altitude to add to his acceleration, pushing the nose of his broom down and again using all the considerable acceleration his broom was capable of to head back toward Arcturus. His speed was just passing the century mark when he jerked the stick of Miss Susan up until she was pointing perpendicular to their direction of travel, and applied maximum lift while using thrust to hold altitude. Miss Susan actually shrieked in what sounded like anger as Richard ran the lift up well into the overload range briefly while they slowed suddenly, and deceleration pinned him to the stick. Just before they stopped, he used his hips to fishtail the twigs back and forth in the old RougherPuff Quidditch team 'sweeping the skies' maneuver, then let the nose of the broom drop to level as they came to a complete stop in the air, using only enough lift to hold them steady in the air while Miss Susan cooled a little.
"Reversed controls is the trick to that, young sir. Use lift and thrust to stop, without touching the braking spell at all."