31 October 2025
+VIDEO In one of those aviation moments that makes you grin and mutter: “They did what?”, a factory-stock CubCrafters Carbon Cub UL has just clawed its way to 37,609ft over the California coast, setting a new record for Cub aircraft.
Yes, 37,609ft. That’s proper oxygen-mask, engine-beyond-its-comfort-zone, in a bush plane on tundra tyres.
The pilot responsible for this aviation triumph was Jon Kotwicki of Fly8MA (that’s him in the photo above).. He launched from San Luis Obispo and spent just over an hour spiralling skyward. Outside air temperature up there? A crisp -51°F (-46°C).
“The Cub flew really easy,” Kotwicki said. “We were outside the normal realm of operating parameters, so we were proceeding with caution.
“It was pretty dang cool to be in a tube-and-fabric bush plane that high, and it was surreal hearing airline pilots over ATC wondering what a Cub was doing up there.”
If the number feels absurd, it is — and it smashes the 75-year-old Super Cub altitude record set by Caro Bayley, who topped out at 30,203ft.
The Carbon Cub UL is powered by a Rotax 916 iS, normally tasked with flying lightweight adventure aircraft not sniffing the edges of the stratosphere. Yet up it went, past the official ultralight altitude record of 35,062ft, previously held by a Long-EZ.
Kotwicki flew with supplemental oxygen and a parachute, but otherwise the aircraft was bog standard.
“We didn’t know how high we could go,” continued Kotwicki. “We were honestly surprised we reached that altitude with 29 inch Alaska Bushwheels installed and all the camera gear onboard.
“The UL is truly an amazing backcountry aircraft. We could have gone directly from over 37,000t to landing and taking off from any unimproved dirt strip anywhere in California. That’s what makes this machine so versatile.”
Project lead and record-collecting professor Paulo Iscold (his 17th record) said, “In test flying we plan for everything to go wrong. When everything goes right — that’s the flight you wanted, that’s the flight we got.”
A Cub at FL350?! 😳✈️ Airline pilots couldn’t believe it either. Hear the LIVE ATC!
On Oct 28, 2025, the CubCrafters Carbon Cub UL, flown by @fly8ma, climbed to 37,609 ft — an unofficial world altitude record for Cub-type aircraft.
A tribute to CubCrafters’ founder, Jim… pic.twitter.com/kUFRrsw35G
— CubCrafters (@cubcrafters) October 31, 2025
