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Laboratory Acrobatics and Supersized Aeronautics

The 25-year-old triumph of two UNLV engineering professors and their quest to build the world’s largest flying disc.

UNLV History  |  Apr 24, 2018  |  By Tony Allen
two men holding old photos

In the early 1990s, engineering professors Brendan O'Toole and Darrell Pepper challenged their students to build the world's largest flying disc. (Josh Hawkins/UNLV Creative Services)

Editor's Note: 

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UNLV is a place where big ideas can soar.

Over its 60-year history, the campus has been a hotbed for the type of heavy innovation that has and will change the world someday: breakthroughs in the fight against disease, new technology that improves how we live and work, giant Frisbees…

Wait, what?  Frisbees. Flying discs. Outsized saucers.

Way back in 1992, young UNLV engineering professors Darrell Pepper and Brendan O’Toole were looking for a way to engage their students beyond textbook exercises. They wanted a project that combined their respective areas of aerodynamics and materials fabrication. And they wanted to take advantage of the world-class Cray supercomputer the university had acquired just a few years earlier. A supercomputer, they reasoned, should help set some sort of super record.

So, naturally, they gravitated toward flying discs.

“Remember, this was before we were working on drones. And it wasn’t just any Frisbee. We wanted to make an impact with our students, so it had to be big — world-record big,” Pepper recalled. And the science behind the saucer would certainly challenge them. “In aerodynamics, subtle changes make a big difference in performance. So if we were going to do it, it would be no small feat.”

Nor was securing the $2,000 or so in funds for the project. The pair submitted a request to the university’s Research Grants and Fellowships Committee. It was denied. After a few modifications and some semantic smoothing — “flying disc” had more intellectual caché than Frisbee — the project finally earned its funding and was ready to take off.

So how do you build a world record-size Frisbee, sorry, flying disc? Never mind building it, O’Toole added, “My first question was ‘Who’s going to throw it?’” (We’ll get to that.) 

If You Build It …

It took more than a year and multiple classroom sessions for Pepper and his engineering students to design the disc and choose the right materials. Just settling on the size was a challenge.

“The students came to me with a design for a disc 3 to 4 feet in diameter,” recalled Pepper. “I said, ‘If you build one like that, somebody’s going to come behind right away and knock [the record] off.’”

After some coaxing, Pepper’s team settled on a 10-foot diameter disc, roughly the size of a backyard trampoline, with a design fine-tuned aerodynamically through trial and error, the department’s wind tunnel, and that supercomputer.

Then they went to O’Toole, the materials guy, to build it. Whoa now, O’Toole thought. He knew immediately that a normal polyethylene disc scaled to that size would weigh hundreds of pounds.  

And if you can’t throw it, it wouldn’t count.

O’Toole settled on light foam core with a Kevlar fabric and epoxy resin cover. It took another year or so of tinkering, a few more engineering class projects, and custom tools to make it work.

“Usually with foam core you use a hot wire cutter, but with a disc of that size we needed to make a custom hot wire saw and employ some laboratory acrobatics to get it right,” O’Toole said.

They did get it right — they hoped — and at just 19 pounds it was light enough to throw. But with its giant size, how would they find someone to throw it?

…Who’s Going to Throw It?

As in all fateful stories, things had a way of working themselves out. It just so happened that a 6-foot-5, 260-pound tackle on the UNLV Rebels football team, Mark Mecham, was a mechanical engineering major. O’Toole volunteered him to make the launch.

With Mecham on board, Pepper, O’Toole, and the rest of the students toted the giant disc to the lawn outside the Thomas Beam Engineering Complex for its maiden voyage.

“Thank God we had Mark,” said O’Toole. “Remember, it was 10 feet across, which made it hard to pick up with the center of gravity five feet in front of you. We needed a big guy to get this thing airborne.”

It took a bit of doing, but Mecham, with disc in hand, spun around a few times to gain momentum and he let it fly. Approximately 40 feet later, the years of hard work — and a big dream — were met with success.

“I don’t know what qualifies as an official world record, but I’d say that’s pretty good,” O’Toole said. “I mean, there’s no catching a disc of that size, so it’s not like you’re going to play a game with it.”

The UFO on the way to Reno

If the air-worthiness of the disc was ever in question, all doubt was put to rest in early January 1997.

Tim Mitchell, a master’s student who’d been involved from early on, was tasked with lugging the disc up to Reno for a meeting of the American Institute of Aeronautics and Astronautics. This was Mitchell’s graduate focus, after all, and also Pepper’s chance to show off UNLV’s achievement in front of thousands of colleagues.

But a funny thing happened on the way to Reno.

Mitchell, with trailer and disc in tow, was hundreds of miles into his journey when a gust of wind ripped the disc from its supposedly secure latch. It soared more than a thousand feet into the Great Basin desert.

With equal parts awe and despair, Mitchell hiked deep into the desert to retrieve it, drag it back to the truck, re-latch it, and hopefully get to the meeting on time. The usual seven-hour trip took 18, but the disc was none the worse for wear. 

At the meeting, the “world’s largest flying disc” was a center of attention and frequent photo stop, both for its size and novelty. “People at first asked, ‘What is that thing?’” Pepper said. “Then they said, ‘You’re kidding me. That’s a Frisbee? Does it fly?’”

If you don’t believe O’Toole and Pepper, maybe ask the truck driver who called in a UFO sighting to the authorities when he spotted it sailing into the desert.

More than 25 years later, Pepper claims the disc is still the world’s largest. Near as we can tell, no one, not even Guinness, has claimed otherwise.

And what about its ultimate fate? Well, it sat around in labs deep inside the engineering building before mysteriously disappearing about a decade ago.

If they could do it all over again? “I’d build a launcher,” Pepper said. “Can you imagine launching it from end zone to end zone at a football game?”


Got a tall tale of campus lore to share? Tell us all about it. We'd also love to incorporate Mark Mecham's side of this story but were unable locate him.