"Across America" Circuit Hits Vegas, Tests Demanding Flight Environment

Swiss electric aircraft developer H55 completed the fourth stop of its Across America tour, and its Bristell B23 Energic aircraft demonstrated the reliability of its electric propulsion system (EPS) in the high heat and low density altitude conditions of the Mojave Desert.

The aircraft performed as expected, validating the system’s resilience and  consistent power output regardless of temperature or elevation.

The proprietary battery and energy management system is engineered to deliver peak performance in extreme environments, and is at the heart of the B23 Energic’s capabilities. Its thermal regulation architecture helps maintain consistent power output and safe operations in elevated temperatures, unlike combustion-based propulsion which, in piston engines, degrades in hot temperatures and at high altitudes.

The H55 flight ops team is led by Céline Bonnefous (Lead Flight Test Engineer), Sasa Blagec and Serge de Wit (Flight Readiness Engineers), and Laurent Wulser (Pilot). They performed a series of demonstration flights with U.S. Air Force test pilots, airline and commercial pilots, flight instructors, and general aviation pilots from Nevada and neighboring states. The B23 Energic performed normally in every flight.

Céline Bonnefous, H55 Lead Flight Test Engineer said, “The H55 electric engine isn’t affected by density altitude. It delivers consistent power regardless of heat or elevation—unlike piston engines, which rely on air density for combustion. In hot or high-altitude conditions, these aircraft suffer noticeable drops in performance, especially during takeoff. That’s a major advantage for flight schools and regional hubs operating in more demanding environments.”

Paniau Lindsey, Chief Flight Instructor at Vegas Aviation, said, “This was my first time using a center stick, so I thought I’d struggle—but it was easy. I’m still shocked. Before flying, I kept thinking, We’re going to fly a plane with no gas? How’s that going to work?

“But once we were up there, there was no issue at all. It’s super quiet—we even took off our headsets and could still talk to each other. I’m going to talk to my school about this right away. I want a couple of these planes. It’s clean, simple, quiet, and flies great. Takeoff was a piece of cake. Steep turns? No problem. It’s a perfect training aircraft. Beautiful flight—this is cool.”

FMI:  across-usa.h55.ch/