Would you spend $100 on a no-frills hamburger on a sesame-seed bun?

Though most people roll into their favorite greasy-spoon diner looking for a bargain, many private pilots nationwide wouldn't think twice about shelling out a Benjamin for a burger.

It's a concept known as the "$100 hamburger," an aviation phrase used to describe both the edible excuse a pilot might use to take his/her plane out for a short (under two-hour) trip, as well as the total price the adventure will cost.

"It's less about the food and more about having a reason to fly the plane," said Dave Colangelo, sitting down to a  plate of whipped-cream-topped Belgian waffles that, flight included, cost him nearly $300. His bill was about 50 times the $6 a local spent eating the same meal at the counter across from him.

"You need a destination," Colangelo explained. "The food is just a novelty that allows you to see a new place."

Playing hooky from work, Colangelo, 27, chief technology officer of  local start-up Jefferson's List, rolled out of bed at 6:30 a.m. on a Friday  in May to begin his breakfast voyage. His destination: the Flight Deck Diner, a cozy and bustling joint at the cusp of the Cape May County Airport.

Departing from  Doylestown Airport, a public airport in Bucks County, Colangelo's 180-mile flight lasted just over two hours round-trip. Because Colangelo doesn't own a plane, he had to rent the Piper Archer that he piloted, causing the flight to top out at well over $100. Even if he had his own four-seater, however, gas alone (currently $5.29 per gallon) would've put the trip at around $120. And that, of course, is excluding costs such as flight insurance, hangar space, and plane upkeep, all of which combined would put the cost of a trip at roughly around $100 per hour.

"You could spend $100 on a night out at the bar, or you could go flying," said Colangelo, adding that his hobby prevents him from drinking on many Friday nights. The Federal Aviation Administration prohibits the ingestion of any alcohol within eight hours of flying, and Colangelo personally prefers to stay alcohol-free for a full 24 hours before taking flight.

"Flying takes a lot of energy, and you need to be fully engaged," Colangelo said. "It's the most mentally stimulating thing I've ever done, which is what I love about it."

Throughout each flight, Colangelo is continuously adjusting the plane's altimeter (altitude) setting. He's responding to cues and cautions from air traffic control officers who are constantly relaying information, such as details about other approaching planes, through a radio feed. He's making calculations on the GPS through the ForeFlight app on his iPad and shifting directions when other planes fly too close to his trajectory. And he's steering, using three types of pedals, dealing with wind streams, and multitasking in more ways than a passenger could count.

"You disconnect from everything because it requires so much focus, so it's one of those hobbies where you really lose yourself in it," said Tiberiu Szabo, 31, a recreational pilot from Doylestown who typically spends at least one day up in the air every week. "It's thrill-seeking because there are these elements of the unknown, but you have full control of your adventure and of what you can do."

For Szabo, who flew into the Flight Deck Diner for a 40-minute meal of eggs Benedict and coffee, flying is all about the excitement of being able to pick a spot on the map and get there in a window of time simply unachievable by car. Average speeds in a small plane generally are between 100 and 200 mph on fair-weather days.

A flight from the Philly area can put you in the Outer Banks in roughly three hours; the Bahamas in seven to eight hours; and Maine, where Szabo recently went in quest of a lobster meal, in about three hours.

"It totally changes the way you think about getting to places as an individual," Szabo said.

Colangelo and Szabo say that, more often than not, food serves as the fun deciding factor in where to go. Trips have included Maryland for crab cakes, Vermont in search of raspberry jam,  North Carolina for ribs (and solar-eclipse viewing), and to Ocean City, Md., for all-you-can-eat crabs. The two also frequently fly into Cape May's public airport, home not only to the Flight Deck Diner, but also just a quick walk from the Cape May Brewery and the Taco Shop, a small spot serving raved-about items like brisket tacos and Mexican street corn.

"Sure, you can get a good crab cake here in Philly, but it becomes an illogical way to justify going out in the plane," Colangelo said.

One thing Colangelo and Szabo aren't eating on their $100 hamburger trips are actual hamburgers.

"A funny old guy once told me about how during one of his first times flying, he got a burger and a Coke," Colangelo said. "It upset his stomach, to stay the least. That story's always something that stuck with me — I usually try to avoid greasy foods when flying."

Bumpy conditions in the air can certainly induce nausea, a distraction pilots naturally prefer to avoid. Pilot Chris Varley confirms that he tries to keep his meals on the light side when traveling by plane.

"I've gotten a $100 lobster, but never a hamburger," said Varley, who's been flying since 2014 and who is training for a commercial and CFI license. "My favorite local trip is to fly out to Lancaster for lunch. There are several options not far from the airport there."

Colangelo, Szabo, and Varley are among the more than 160,000 private licensed pilots in the country, according to an estimate released by the FAA in 2017. (Of that number, only a little more than 6 percent are estimated to be women.) There are 14,000 U.S. landing facilities where private planes are able to touch down, many of which have cafes and restaurants just steps from the runway.

At the picnic tables often stationed outside the landing facilities, it's not uncommon to find families hanging out, watching as their kids' enthusiasm builds with each plane that flies in and out. Sometimes you'll find a retired older commercial pilot pulling out his lawn chair, sitting back to take in the scene and talk shop with pilots who travel in and out of the area.

For Flight Deck Diner patron Mike Ross, the planes provide a free source of entertainment to enjoy at one of his favorite breakfast spots.

"A pilot friend of mine brought me in here about 15 years ago, and I've been coming ever since," Ross said. "You get good food, good people, and then you have the backdrop of planes, which are always fun to watch as they take off and land."

Though people fly all year round, summertime tends to bring an uptick in trips. Many pilots will report, however, that fall is their favorite season, saying that foliage views from overhead are unparalleled.

"Sometimes, I look at the numbers of what I'm spending, and I'm like, 'What am I doing?' " said Szabo, who estimates he could conceivably be spending as much as $8,000 a year — and maybe more — on the hobby. "But I absolutely love it — there's just no thrill that comes close to this."