Oshkosh, Wisconsin (CNN) — While the rest of America has been watching the presidential conventions, avgeeks from around the world have been rocking a kind of aviation Woodstock.

Hey, peace, love and music are great, but the huge annual AirVenture air show in Oshkosh, Wisconsin, is focused on celebrating the miracle of flight.

This year's lineup includes eye-popping airlifters, amazing "skytypers" and a daredevil wing walker.

CNN gained access to a few exclusive thrills aboard some of the best airplanes at Oshkosh -- and now we're ready to share them with you.

So here they come: Five "wow" moments from America's greatest air show.

Gigantic messages across the sky

They're the aviators who can write messages in the sky as big as New York's Empire State Building.

CNN video producer Madeleine Stix joined the squadron of six GEICO Skytypers to document how they get it done from their North American SNJ-2 propeller airplanes, flying between 7,500 and 9,500 feet high, 200 feet apart at about 130 mph.

A typical message is 20 to 25 characters in less than 2 minutes. A message can be from 2 to 5 miles long.

When your penmanship and spelling skills are on public display like that, you'd better not screw up.

So, how does that work? How do the pilots make sure to get their skywriting messages perfect every time?

Commanding officer and flight lead Larry Arken carries a small computer device with him that's pre-loaded with messages and is wirelessly connected to the other five pilots.

When the planes are in perfect formation and it's time to begin "skytyping," the computer coordinates with devices on the other five airplanes.

The GEICO Skytypers wrote "CNN.com" across the sky at the Oshkosh airshow.

Then each aircraft starts releasing puffs of smoke in a precise pattern that results in perfect messages stretching across the sky.

There's a lot more to it than you might think. The process is a precisely, delicately and beautifully choreographed mechanical and aeronautical ballet in the sky, executed by a group of highly trained professionals with decades of military aviation experience.

"My dad bought the airplanes and started this skytyping business when I was 17," Arken said on the airfield after the flight. "Later on, I got him to start into air shows, and I've been running it about 22 years."

The C-5M Super Galaxy: 'It looks bigger in real life'

I knew the U.S. Air Force Lockheed C-5M is the biggest airplane of the entire U.S. military fleet, but it wasn't until I stood several hundred feet away at Oshkosh and sized it up in person that I understood how big it really is.

The biggest plane in the U.S. military fleet, a Lockheed C-5M Super Galaxy, raises its visor shortly after landing at Oshkosh on Tuesday. Thom Patterson/CNN

"It looks bigger in real life," said an air show fan who was standing next to me -- stunned in avgeek awe.

"Yeah," I said. "It really does."

How big is it?

The C-5M Super Galaxy is so big that its cargo hold could swallow the body of another big Lockheed cargo plane, the C-130. But come on now, who would really want to do that with a perfectly good C-130?

It's so long that the floor of its cargo hold is actually longer than the first flight of the Wright brothers.

The Super Galaxy is so gigantic that pilots say the most challenging thing about it is filling it up with fuel in the air and making sure it doesn't bump into anything when it's on the ground.

Geek alert: Exclusive access

Air Force Reserve pilot Capt. Matt Anger, of the 349th Air Mobility Wing based at Travis Air Force Base in California, helped us get inside this gigantic plane and up into the passenger area, which was off limits to the public tour.

Thanks to the crew's loadmaster, a hand crank in the rear of the cargo hold lowered a ladder which allowed us to climb up to the top of the plane. There, we found rows of airline-style seats facing the rear as well as two lavatories and a galley.

The huge Empennage Access Area shows just how big the C-5M Super Galaxy is. Thom Patterson/CNN

We also found a huge Empennage Access Area, an unused space inside the aircraft's tail. The fuselage vent system, emergency ropes and a huge grate that allows a way out in case of an emergency are also at the rear of the plane.

On the roomy flight deck, Capt. Anger showed us the cockpit systems and a spartan crew rest area.

Anger's been flying the C-5 -- a childhood dream -- since 2012. As a kid growing up in Southern California, he'd go to air shows with his grandfather, where he'd see the giant airlifter.

After stopping in Oshkosh, Anger and the C-5M crew plan to head off to serve a humanitarian mission, delivering fire engines to South America.

Secrets of wing walking

Walking on airplane wings while they're flying isn't dangerous.

Right?

At least that's what wing walker Ashley Key thinks.

We spent some time with Key and her fiance Greg Shelton -- who also doubles as her stunt pilot -- at an Oshkosh hangar where he keeps his Super Stearman aerobatic bi-plane.

There, Key shared some of her wing-walking secrets.

Hardest maneuver:

For Key, the hardest wing-walking maneuver is moving out along the plane's bottom wing onto the javelin -- the wooden bar that connects the flying wires and landing wires.

"You have so much drag on your body with the wind, it just makes it more challenging to hold on," Key said.

"The trick is doing it the same every time. When you step off of it, I know exactly where to step. I know how many steps when I'm up there. I know where my feet should go to get back into the cockpit. Do it the same every time, and there are no mistakes."

Matt Tisdale's Air Cam doesn't fly as high, or as fast, as most planes, but he says it's one of the most relaxing planes to fly, and it has a great view.

Key wears a climbing harness around her waist and legs.

"I have two carabiners: one that's attached to the harness and one that's attached to the airplane. It's a fairly short cable so I don't have a lot of give with that and it keeps me tethered to the airplane," she said.

Upside down:

It's the maneuver when she has to hold on the tightest. She calls it the inverted pass. Basically Key is hanging upside down from the wing of the plane.

"The blood rushes to your head, and you're trying to wave," she said. "For me that's the most strenuous part of it. It is a good work out. You work on your grip strength."

Getting started:

Key began her wing-walking career after meeting Shelton through mutual friends. They started dating and then -- when Shelton's wing walker retired -- Key offered to try out as her replacement.

"It worked out, and it's a lot of fun," Key said.

She said she'll be wing walking until she and Shelton have their first baby.

Wing walker Ashley Key doesn't think her unique talent is particularly dangerous. Thom Patterson/CNN

The world's largest flying water bomber: Hawaii Mars

Hawaii Mars, the star of this year's Oshkosh air show, has been docked at the event's Seaplane Base all week.

On Monday, when the plane's owner Wayne Coulson led me on a tour of the aircraft, we paused at a ladder that led up to a round hatch.

"Do you want to climb up onto the top and walk out onto the wings?" he asked.

I laughed. "Hmmm, let me think about that for a few minutes -- YES!"

Being allowed to set foot on Hawaii Mars' massive 200-foot wingspan was a thrill.

This plane had seen so much history -- from the World War II-era in the Pacific where it had served as a troop transport to another role as a hospital ship to its most recent firefighting mission.

In the 1950s, the plane was decommissioned and sold to a private company. That's when it was outfitted as a firefighting water bomber.

Coulson shared a personal story with me that day from almost 30 years ago when he was on the ground fighting a wildfire on his family's property.

"We thought we were going to lose the whole mountain, and then we heard the thunder in the valley as the [Mars] came overhead."

Two water drops later, Coulson said, the fire was out.

Wayne Coulson, the owner of the world's biggest water bomber, has announced he's selling his plane for $3 million.

"From that point, we knew if there was ever an aircraft that could kill a wildfire, it was the Mars."

Over the years, countless lives and property has been saved by this airplane and its sister water bomber, Philippine Mars.

This week Coulson's company put both the Hawaii Mars and the Philippine Mars up for sale.

The Snowbirds return to Oshkosh

"Graceful" is the word often used to describe Canada's military aerial demonstration team, the Snowbirds.

For decades they've been thrilling audiences around the world, squeezing every ounce of energy from their classic Canadair CT-114 Tutor jets.

Flying in a nine-jet formation instead of the typical six, sometimes the Snowbirds' wings overlap by as much as four feet.