His father was afraid to fly, but North Korean leader Kim Jong Un has taken to the skies, building a series of small runways long enough to land light, private aircraft next to some of his palaces, satellite imagery shows.
Construction on Kim's personal landing strips began in 2014 and some were completed as recently as last month, according to satellite imagery identified by Curtis Melvin of the US-Korea Institute at Johns Hopkins University in Washington.
"These runways are located near Kim family compounds - sometimes within the security perimeters - and next to private train stations that were used by Kim Jong Il," Melvin told Reuters.
The young leader's father, Kim Jong Il, was famously afraid of flying and traveled everywhere by armored train - including on official state visits to China and Russia.
But Kim Jong Un has paid much attention to aviation during his three-year rule over the isolated and impoverished country.
State television has shown him piloting planes - including a small Cessna-like single-engined plane manufactured in North Korea - and sitting in the cockpit of a fighter jet.
Photos shown at a state concert in April last year showed Kim as a young boy, dressed in a child-sized North Korean air force uniform and saluting. He has hosted two "flying contests" for North Korean pilots since he came to power in late 2011.
In addition to various titles, Kim also officially holds the rank of Marshal in the North Korean military.
AIR FORCE UN
One of the five new runways, beside a private palace in the eastern port city of Wonsan, was built over a helipad where Kim greeted basketball player Dennis Rodman and his delegation in September 2013.
The 500-metre-long airstrip is a few hundred meters (yards) from the Songdowon Children's Camp, and a sandy tourist beach open to foreigners.
The palace area is also home to Kim Jong Un's private yachts, jet skis, and villas he uses to entertain friends and guests.
Another landing strip identified by Melvin lies a short drive from another sprawling palace complex where Japanese sushi chef Kenji Fujimoto said in his memoirs he spent summers with the late Kim Jong Il.
In February, state media released photos of Kim Jong Un inspecting Pyongyang construction work from the windows of his private jet - a converted Soviet-era Ilyushin IL-62 named "Chammae-1" after a native species of hawk. The inside is plush, with leather chairs, crystal ashtrays and large wooden tables.
After inspecting a factory making light aircraft in April, Kim Jong Un "personally conducted" a take-off and landing test.
"I have to try the airplane as it was produced by our working class," Kim Jong Un said, according to state media.