PYONGYANG, North Korea — As if traveling to North Korea weren't adventurous enough, a group of 75 self-described "aviation geeks," including a handful of Americans, has just spent five days flying in Soviet-era aircraft around a heavily sanctioned country that struggles to get parts and jet fuel.

For airplane aficionados like Brian Crooks, who works in human resources for United Airlines based at Dulles airport outside Washington, and Jamie Baker, an aviation analyst on Wall Street, flying in and around North Korea was a dream come true.

"It was amazing to fly on all these Russian planes I'd seen but never had the opportunity to fly on," said Crooks, who lives in Washington and wants to visit every country in the world before he's 45. (He's not doing too badly so far, at 127 countries by 36.)

Crooks, along with veterans of Delta and Boeing, joined a five-day trip run by Juche Travel Services, a U.K.-based travel agency, especially for plane geeks. They're all platinum- and diamond-level frequent fliers, who sat in the bar of the Koryo Hotel on the night they arrived in Pyongyang talking about the shortcomings of business class on Afriqiyah, the Libyan carrier, and the pluses and minuses of TAAG Angola.

In North Korea, they'd come to a country led by a planeophile. Kim Jong Un has been featured in state media flying an Antonov AN-148 and has apparently had airstrips built around the country so he can fly himself around, in addition to the new airport terminals he has had constructed in Pyongyang and Wonsan.

The participants on last week's trip, however, traveled on charter flights flown especially for them. Each person on the trip got to choose flights "a la carte" at a little over $200 a pop. Crooks was astounded to fly on a Tupolev TU-154, which requires four pilots and sees only five hours of flight time each year in North Korea.

"We went to these beautiful new airports and we were the only flights on the departure boards," Crooks said.

While operational Tupolevs and Ilyushins (another Russian aircraft) can be found in countries such as Cuba, Afghanistan and Sudan, no airline beyond North Korea's Air Koryo has such a relatively large and varied fleet of these planes.

The combination of the collapse of the Soviet Union and decades of sanctions means that North Korea has been unable to afford or procure new planes. So its fleet remains stuck in an era when Tupolev could give Boeing a run for its money.

That makes North Korea a "a bucket-list place for Soviet-era aircraft," said David Thompson of Juche Travel Services. "It's the last place where you can fly on all these different kinds of aircraft. It's something that aviation enthusiasts want to tick off."

The most recent round of sanctions, following this year's nuclear and long-range missile tests, added another wrinkle: It is now prohibited to sell aviation fuel to North Korea. Furthermore, the State Department strongly advises Americans against traveling to North Korea.

But somehow, the show managed to go on.

"They're so beautifully maintained. It's like stepping back in time," said Ashley Walker, a British pilot who flies 747s for Cathay Pacific. He couldn't wait to get aboard an Ilyushin IL-62, a narrow-bodied airliner with its engines at the rear and a little wheel that pops out the back.

"I used to fly into Beijing a lot and see the [Air Koryo] IL-62 in front of me and think, 'There's no way you'd ever get me in that aircraft,' " Walker said. "But the more I thought about it, the more I knew I had to do it." He'd even booked a seat near the notoriously loud engines so he could hear them at work.

Jeff Cacy of Seattle, who started his career at Alaska Airlines and finished it at Boeing, was dying to get on a Tupolev TU-134, the noisy, twin-engine airliner that Aeroflot retired in 2007. "When I was working at Alaska Airlines I was working in the Soviet Far East, so I have some romantic notions about these Russian airliners," he said.

While the planes were a draw, the mystery of North Korea added another layer of intrigue, said Andrea Ciasullo, a manager in the mechanical engineering department at Delta, based in Atlanta. "I love to see new places and I love traveling in Asia," she said.

"We can build bridges and see some cool airplanes at the same time," added her friend Rebekah Michaels, a former Delta manager who now works in aviation consulting. "I'm here to see North Korea first and the planes second."

Baker, the aviation analyst, said after the trip that flying Soviet aircraft, not to mention in North Korea, was like gliding into another era.

"These aircraft lack most of the creature comforts travelers today expect, such as overhead bins," he said. "They're loud, you can smell oil and jet fuel from within the cabin, they require several pilots in the cockpit, but they are exactly what so many of us came here to experience."