Kaesaero, a company specializing in unique aircraft, flew an ultralight hydrogen amphibian on September 23. Often considered as too heavy and bulky for light aircraft, hydrogen has been seen recently on commercial commuter craft, but rarely on puddle-jumpers available at your local airport.
The outing by a Dornier DS-2C, described by Dornier as, “a two-seat amphibious, light sports aircraft manufactured from lightweight, carbon fiber materials. Light by design, but incorporating structural integrity for safety of flight. The aircraft can host up to two occupants and 100 liters of fuel, which secures your next adventure.”
Kasaero replaces the standard Rotax engine with a fuel-cell system and retains ultralight status
Normally powered by a Rotax 912iS Sport engine of 73.5 kilowatts (95.5 horsepower), the two-seat, 650 kilogram (1,430 pound) craft has a maximum cruise speed of 250 kilometers per hour (155 mph) and a stall speed of 73 kilometers per hour (45 mph).
Its 9.18 meter span gives it a rate of climb of 3.2 meters per second (630 feet per minute) and the ability to take off from land and over a 15-meter (50-foot) obstacle in 320 meters (1.050 feet). From water, the same maneuver takes 803 meters (2,635 feet). Landing distances over a 50-foot obstacle require 460 meters (1,509 feet) on land and 590 meters (1,936 feet) on water.
Karl Kaeser of Kasaero, a long-time contributor to the electric airplane world, improves on an already impressive amphibian. His firm has developed a hydrogen-fueled system that changes expectations for such power units.
How Kasaero/HyFly actually fit components into the Dornier hydrogen amphibian
Start with the spherical H2 container that enables “five times more endurance than battery-electric systems, according to Kasaero affiliate HYFLY. Their tank, holding seven kilograms of H2 at 700 bar (10.150 pounds per square inch) is strong but light. Still a bit bulky, it’s much smaller than comparable H2 containers.
“The spherical hydrogen tank is wound from a very high-quality carbon fiber using a new process. Extremely low quality fluctuations and a particularly high load-bearing capacity of the fibers reduce the specific tank weight from 15 kg per kg of hydrogen to a ratio of 5:1. ‘That’s a real quantum leap, ‘says [Manager Peter] Stadthalter happily.” For the seven kilograms of hydrogen in the tank, that means dropping the containment weight from 105 kilograms (231 pounds) to 35 kilograms (77 pounds).
Kaeser explained the development at Aero Expo in April. Turn on Closed Captioning to get a somewhat misspelled interpretation over the background noise. Note especially that the H167 system weight seems to be lower than that of the Rotax installation, although your editor will make further queries.
As designed, the H167 system can be “Configurable for various aircraft types, including ultralight aircraft (LTF-UL, Germany), CS-22 (interestingly, European touring motor glider), and LSA (Light Sport Aircraft USA),” according to HyFly. That it can fly within several country’s regulations makes it a viable solution for repowering vintage craft or motivating new designs. Kasaero and HyFly seem to have hit on a clean future for ultralight flight.
One More Thing (added December 1)
Your editor first met Karl Kaeser at the 2013 CAFE Foundation Symposium in Santa Rosa, California. Ron Gremban, who had developed the Toyota Prius Plug-in car, had alerted us to dangers surrounding electric aircraft that did not exist with more conventional airplanes. Electric airplanes, for instance, sit quietly with the motor shut down, never idling like their fossil-fuel brethren. The sudden swipe of an electrically-powered propeller could take one unawares. Karl came up with a solution, an “ePropeller Safety Device (eSD), noting “the risk to people, animals or objects in the propeller disk area and that they can be injured or damaged accidentally during the run-up of the propeller.” He first noted that issue in the case of e-Genius, on which he was “charged with the production management of the e-Genius, first in the workshop shed of the Institute of Aircraft Design of the University of Stuttgart, then at Grob Aircraft in the city of Mindelheim. He acted as team member and occasional pilot at the Green Flight Challenge.”
The video of his eSD in action shows a Lego pilot being literally decapitated – having his cap knocked off.
Ron Gremban and Karl Kaeser have been pioneers in a very new field. Their contributions have helped bring us along to the entryway to a very different world.