Small US aerospace project Helios Horizon claims to have recently broken the record for the highest-flying multi-seat electric aircraft, which it considers a step on its journey into the stratosphere.
Chasing the sun : Helio progenitors -- Dawn of the "tennis court airplane" : early Helio prototypes -- Geared for success : main production models and variants, 1954-1974 -- Litterbugs and black ops : ...
Next test flights in converted Pipistrel Taurus light aircraft will target altitudes above 40,000 feet Helios Horizon has converted Pipistrel Taurus aircraft to fly ...