Engines
Helios Horizon Aims to Take Electric Aviation to the Stratosphere
Next test flights in converted Pipistrel Taurus light aircraft will target altitudes above 40,000 feet
Helios Horizon's electric-powered Pipistrel Taurus aircraft
Helios Horizon has converted Pipistrel Taurus aircraft to fly with its electric propulsion system at altitudes above 40,000 feet. © Helios Horizon/James Darcy

Helios Horizon is looking to take electric aviation quite literally to the next level as it steps up its efforts to prove the efficacy of operating at altitudes as high as 44,000 feet. The U.S.-based start-up is preparing to resume flight testing in the fall with a Pipistrel Taurus light aircraft converted to use its battery electric propulsion system in a bid to reach the higher flight levels it says will deliver longer range.

Flights conducted near Bishop, California, in April and May saw the aircraft expand its envelope from 17,500 feet to 24,000 feet, using no more than 60% of its battery capacity. The Helios Horizon team, which includes veterans of green aviation projects such as Airbus’s Perlan, Solar Stratos, and Solar Impulse, is aiming to progressively fly higher and reach stratospheric altitudes by early 2026.