Thunderspite

The next day was Sunday, and Applejack insisted that Thunderspite take the day off. Thunderspite and Rainbow Dash took the opportunity practice flying as a team. High above the plains west of Ponyville, Thunderspite showed her how to spring an ambush by hiding behind clouds, how to fly in close formation in order engage multiple enemies at once, and how to take enemies by surprise by diving out of the sun. Together, they laid waste to entire legions of enemy clouds.

All morning long they dove and swooped and charged through clouds in beautiful synchronization. As they burst one particularly aggressive cloud, however, a very surprised-looking pegasus pony came tumbling out.

“Aah!” The pony tumbled a few times, but quickly recovered and came to a hover, looking very dazed.

Rainbow Dash and Thunderspite slowed and came about. “Ohmygosh!” exclaimed Rainbow Dash. “Snow Bolt, is that you? Are you okay?”

“That’s me, Dashie,” said Snow Bolt, rubbing her eyes. “Was just having a little nap.”

“I am so sorry!” said Rainbow Dash. “We didn’t think there’d be anypony else out this far from Ponyville.”

“It’s okay, Dashie. No worries.” Snow Bolt shook her head to clear the last of her sleepiness.

Rainbow Dash made introductions. “Snow Bolt, this is Thunderspite. Thunderspite, Snow Bolt.”

“We've met before, actually,” said Thunderspite flatly, but took Snow Bolt’s hoof anyway. “We… ran into each other that day we were moving the cake.”

“Oh, haha, that’s right.” Snow Bolt blushed and rubbed the back of her head.

“What are you doing this far from Ponyville?” Rainbow Dash asked.

“I was just out for a little fly.” Snow Bolt did a quick backflip. “Stretch my wings a little bit, you know? Except I guess I got tired.” Snow Bolt gasped then, as an idea struck her. “Ohmygosh you guys! You should totally come flying with me!”

Rainbow Dash was unsure. “Well... see the thing is, we were just in the middle of training—”

“Oh pleasepleaseplease, Rainbow Dash! You always say you’re going to come flying with me, but we never get around to it!”

There was a long pause as Snow Bolt stared pleadingly at Rainbow Dash, her eyes as big as dinner plates. Snow Bolt had asked her on several occasions before to come flying with her, but Rainbow Dash had always politely declined. Rainbow Dash was feeling kind of bad about it now, not to mention the rude awakening from nap. She looked over at Thunderspite, who smiled a bit and nodded.

“Well... okay,” Rainbow Dash said at last.

“Yes!” Snow Bolt pumped both hooves. Then she gasped again, as another idea struck her. “Ohmygoshohmygoshohmygosh you guys!” She flew close to them, as if to tell them some great secret. “We... should go... wump-crumping!”

Rainbow Dash mirrored Snow Bolt’s excitement. “Oh my gosh, we totally should! We should go wump-crumping!”

“Ohmygosh I know just the place! Follow me!” And with that, Snow Bolt dove and turned north. The other two followed suit, trailing a short distance behind her.

“Rainbow Dash,” asked Thunderspite in a low voice, “what is wump-crumping?”

“I have absolutely no idea.”

“Your friend certainly is... enthusiastic,” said Thunderspite, watching Snow Bolt roll and slalom with excitement ahead of them.

“Mister, you have no idea.”

* * *

After about half an hour of flying, the three pegasus ponies at last reached their apparent destination, a high mountain ridge many miles northwest of Ponyville. Snow Bolt led the three to the top of the ridge, where she landed and immediately began surveying both sides. A stiff wind was blowing from the south, making a low whistling noise as it passed over the mountaintop.

“This should do nicely,” said Snow Bolt with a definitive nod. “Have you guys been wump-crumping before?”

“Can’t say that I have,” said Thunderspite.

“I could uh, use a refresher too,” said Rainbow Dash.

“Okie Dokie!” said Snow Bolt. “Now remember, the first rule of wump-crumping is no flapping allowed.”

Thunderspite asked the obvious question. "How exactly does one fly without flapping?”

Snow Bolt giggled mischeviously. “You’ll see. Okay! So before we can start wump-crumping, we have to learn to soar. That part’s super easy. All you have to do is run into the wind a little bit, spread your wings, and... ” she demonstrated, trotting down the windward side of the ridge a few steps, then spreading her wings and let the rising air carry her upwards. She hovered above them for a moment, her wings perfectly still, then she folded her wings and dropped gracefully back to the ground to join them.

“How... did you do that?” asked Rainbow Dash.

“Soaring is easy!” said Snow Bolt. "See, the wind hits the mountain, and it has to go up to go over. So all you have to do is spread your wings... ” she did so again, and just as before, she lifted gently in the air and hovered above them. “And you go up too! Try it!”

Rainbow Dash and Thunderspite did as she said, and they were also lifted into the air. At Snow Bolt’s direction, they all spent a few minutes gliding gently back and forth across the ridgeline, until they got the hang of it. Rainbow Dash soon grew bored of the relatively slow pace, and flapped a few times in a turn to gain a bit of speed.

“I saw that, Dashie! No flapping allowed! Okay, I think you’ve got that part down.” They all landed on the ridgeline again. “Okay, this next part is where it gets tricky. While you’re gliding around, you get as much altitude as you can, then you dive behind the mountain, then come back up into the wind. So it’s a loop-de-loop, but sort of an angle, get it? Watch me.”

She lifted off again. She glided away into the wind a ways, gaining much more altitude than before. When she was about a hundred feet up, she shouted down to them. “Okay, here I go!” Then she banked to the left and dove, down behind the ridgeline on the leeward side.

“What’s she doing?” asked Rainbow Dash.

“I’m not sure,” said Thunderspite, watching Snow Bolt intently.

Meanwhile, Snow Bolt was continuing her turn, and was now heading back towards the ridgeline. She passed up and over and back into the wind with a loud whoosh, then turned back down behind it again, completing the circle.

“Did she pick up speed right there?” asked Rainbow Dash.

“That’s just what I was thinking,” said Thunderspite.

Snow Bolt made several more loops, identical to the first, but this time there was no doubt that she was indeed accelerating with every pass.

“How the... ” Rainbow Dash could only watch in amazement. Snow Bolt was picking up incredible speed, and still hadn't flapped her wings once. Faster and faster she went, the diameter of her circuit widening each time. After a few more loops, her wings began to draw sharp contrails through the air. The air hissed and sizzled as her wings sliced through it like a knife through rice paper.

“Watch this, Dashie!” Snow Bolt shouted, and after the next circuit she broke out of the circle and shot straight up into the air like an arrow, until she was only a tiny speck against the sky. Then she rolled, dove, and assumed an aerodynamic tuck, with her front hooves reaching far out in front of her, her head between them and her rear hooves pointing straight backwards, squeezing herself into a cigar shape. Faster and faster she hurtled towards the ground, aiming for the leeward side of the ridge as before.

As she passed below the ridge, Snow Bolt somehow managed to pull up, despite the incredible speed. As she came back up above the ridgeline, not far from where Thunderspite and Rainbowdash stood, she tucked herself into as small a cross-section as possible, and crossed the sound barrier.

BOOM. There was a noise like thunder, louder than either of the two pegasi had ever heard before, followed by a crystalline ringing sound, like a spoon striking a glass goblet. A circular cloud exploded into existence just above the ridgeline and rapidly expanded outwards in a shockwave that knocked both Thunderspite and Rainbow Dash to the ground. BOOM... BOOM... boom... the noise echoed back and forth across the mountain range like a heartbeat. A moment later, Thunderspite and Rainbow Dash gathered their senses and discovered that they had both been covered in a light dusting of snow. In fact, there were still big, hoof-sized snowflakes drifting down from the cloudless sky.

It took Snow Bolt half a minute to decelerate enough to land safely. She wove her way back and forth across the windward side of the ridge, scrubbing off speed by flying sideways, like an ice skater performing a hockey stop.

When she finally landed beside the two dumbstruck and snow-covered ponies, she couldn't help but laugh at their expressions.

"OH MY GOSH THAT WAS SO AWESOME" Rainbow Dash was literally trembling with excitement.

"That was incredible," said Thunderspite, his jaw agape. "A sonic...snowboom?"

"Yeah! A sonic snowboom!" Rainbow Dash was hopping with excitement. "Snow Bolt, that's like the most awesome thing I've ever seen! Where did you even learn to do that? How does that even work?"

"…constantly exchanging air speed for ground speed." Thunderspite was muttering to himself in amazement. "…exploiting the energy potential of the differential air masses. If the shear layer was thin enough, the energy potential would be...extreme...”

"Wait a second!” Rainbow Dash whirled and pointed a hoof at Snow Bolt, accusingly. “That’s what you call wump-crumping?!"

Snow Bolt was blushing from all the praise. "C'mon you guys. I'll show you how it's done."

* * *

Under Snow Bolt's watchful instruction, Rainbow Dash and Thunderspite each took their turns practicing the maneuvers Snow Bolt had showed them. They were both quick studies. Rainbow dash had an incredibly aerodynamic tuck posture, while Thunderspite was an expert in making quick, efficient turns. After only a few circuits, it became apparent to both of them why Snow Bolt called it "wump-crumping." There was a definite “wump” sound as they crossed the invisible boundary separating the windy face of the ridge into the still air on the leeward side, and a somewhat more crisp "crump" sound when they crossed back again. Once, Rainbow Dash made the mistake of flapping her wings in an effort to increase her diving speed, and instantly spun out and nearly crashed into the ridge. Snow Bolt’s “no flapping” rule was indeed mandatory, as losing turning authority at that speed for even an instant would result in disaster. Eventually Rainbow Dash learned to give up trying to fly under her own power, and trust herself to the invisible currents of air that flowed around her.

Before long, Rainbow Dash was proficient enough in the technique to trigger a sonic rainboom. She had done plenty of sonic rainbooms before, of course, but never at such low altitude. Thunderspite and Snow Bolt both cheered mightily as the multi-colored shockwave passed just overhead and they were both knocked from their hooves.

It took Thunderspite considerably longer to break the sound barrier, but after plenty of coaching from the other two, he was able to reduce his drag just enough to push him over the edge. When he finally did break through, his sonic boom generated an expanding, rolling thunder cloud that flashed lightning and rumbled thunder as it went. When Thunderspite had slowed enough to join them again on the ridge, he was smiling more broadly than Rainbow Dash had ever seen him. She thought she may have even seen some teeth, just for a moment.

The sun was low on the horizon by then, but before heading back to Ponyville, they decided that they should all try it in formation together. They all lifted off and glided gently into the wind, forming a triangle, with Snow Bolt in the lead.

When they had gained enough altitude, Snow Bolt turned to the others. "Alright, here we go! Stay right on my wingtips!" she said, and the three ponies banked and dove behind the ridgeline as one.

With the three of them flying in such close formation, they were accelerating much faster than any of the ponies had managed individually. Wump. Crump. Wump! Crump! Faster and faster they went, with Snow Bolt increasing the diameter of their circle each time. Before long, they had reached their critical velocity.

There was no hope of speaking and being heard at that speed, but Rainbow Dash and Thunderspite were watching Snow Bolt's flight posture, and knew instinctively when she was ready to make a push for the barrier. All three of the ponies assumed their tuck simultaneously, and all at once, they broke through.

They each felt the sonic boom, and they knew it was big. Looking behind them, they all let out a cheer as they saw a rainbow-colored thunderhead expanding outwards, shedding snow as it went.

After rebounding off the sonic boom, they shot impossibly high in the air. There they broke formation and individually began their deceleration maneuvers. They met back up on the ridge a few moments later, all talking excitedly.

"THAT WAS AWESOME!" shouted Rainbow Dash.

"THAT WAS EPIC!" shouted Snow Bolt.

"That was impressive,” said Thunderspite mutedly, though his broad smile betrayed his real excitement.

"Sonic superboom! Sonic Superboom!" Snow Bolt and Rainbow Bash were chanting together.

"Look there," Thunderspite pointed. What few trees that stood along the ridgeline had all been flattened.

"Whoa!" said Snow Bolt and Rainbow Dash together. The three of them flew over to examine the damage. One tree's trunk had simply snapped at the base, the other two had been ripped from the ground completely, their roots hanging in the air. In examining the surrounding area, they also saw several large boulders had been moved some ways from their original position, and the entire area was covered in a thin blanket of snow.

The sun was setting when the three ponies finally began to head home. They laughed and carried on, recounting their favorite moments of the day's adventure. "Best day ever," stated Rainbow Dash matter-of-factly, and the other two agreed.