Richard kept a careful eye on Arcturus' first adventure on a high-performance broom, chuckling softly when the young flier found himself upside down.
"It happens. Easy to overcontrol at low speeds with a broom that responsive. Doesn't take much of a slip to roll past 90 degrees. At least you didn't try to force a recover and end up rolling over the other way."
He thought for a moment. "You are held to the ground by the force of gravity. It is an arbitrary measurement; One gravity, abbreviated as just 'G'. When you pull up out of a dive, you feel heavier. We call that positive G. When you push over to level flight from a climb, you feel lighter. That is negative G. If you are upright, the blood wants to run out of, or into, your brain. Lay down on the broom and the effect isn't so pronounced. A trained and conditioned flier can pull between eight and ten positive or negative Gs that way. That is, a force of eight to ten times what they weigh just standing on the ground. Usually a little more negative than positive."
Nodding, he went on, "Depends on the person, but between eight and ten thousand feet the air is too thin to breathe. Not enough oxygen. My helmet is spelled to give me breathable air up to about twenty thousand, but it is bloody cold up there. One of our factory riders wore a special heated suit and helmet, and took a one-off broom up to just above fifty thousand, but it was a stunt for publicity, and not practical for even most skilled fliers."
"Take the lady out for another turn on the dance floor, young sir. Try a little more power, and a lot less control input. She will just about be able to follow your lead if you only think about where you want her to go. When she starts to get away from you, just ease off a little until you are back in sync. You have a sure hand on the stick, now you need to learn how to have a light hand as well."