This year’s AeroExpo was particularly supportive of sustainability, with green balloons over “green” displays, a series of seminars on electric, hydrogen, and other clean skies aspirants, and flight demonstrations showing how far the industry and the Friedrichshafen exhibit have come.
Alphafrog’s Illustrious Ancestor
Alphafrog is a reintroduced and wildly updated ultralight from the 1970s, the Sirocco. Its high wing, pusher engine, and forward cockpit made for a comfortable way to cruise at leisurely speeds while avoiding the rigors of more open aviating. Even the original 1983 version, a wire-braced monoplane with three-axis control, had a polyester fiber-glass fuselage and fiber-glass leading edges on wings and tail surfaces. Spars were “bidirectional stratified” composite construction. (Burger-Burr’s Ultralight Aircraft of the World, 1983, a Foulis Aviation Book)
The original, even with a partially-open cockpit, was capable of an around-the-world tour. As Alphafrog relates, “Forty years ago, on September 29, 1984, Patrice Franceschi embarked on the first circumnavigation of the world with an ultralight aircraft, the Aviasud Sirocco, covering a distance of 36,000 km. He flew over 33 countries and was on the journey for 909 days. An incredible achievement, especially by the pilot, but it also demonstrated what was possible with a plane weighing only 130 [kilograms] (286 pounds). To mark the anniversary of this first circumnavigation, we are releasing the limited edition‚Patrice Franceschi – 40 ans Tour du Monde‘.” Achieving this with a two-stroke engine in the 1980s was even more stunning, your editor having witnessed early ultralight fly-ins and the attendant forced landings in fields around the host airports.
An Electric, Electronic Update
Alphafrog may be a 43-year-old design, but it’s still remarkably advanced for an ultralight, and since the design’s been taken over by a German software firm, even more ahead of its time now.
Alphafrog comes in a modern two-stroke version with a single-cylinder, an Austrian EOS Quatro. Alphafrog describes it as having, “The least noise problems of all pilots flying combustion engines. The only way to get even quieter is to switch to electric.” For that, and even greater sustainability of flight, Alphafrog eG1 can be equipped with a Geiger HPD 20/30 electric motor.
Alphafrrog team relaxes with gas-powered G1
The electric frog is actually 13 kilograms (28.6 pounds) lighter than the gas-powered version, but both have the same maximum takeoff weight of 300 kilograms (660 pounds). The eG1 weighs 118 kilograms (259.6 pounds), well within the EU 135 kilo rules. Its cruise speed of 120 kilometers per hour (74.4 mph) and top speed of 140 km-hr. (86.8 mph) are also within European rules. Alphafrog’s range of 150 kilometers (93 miles) gives over an hour ot sight-see in zero-emission comfort. Restrained to lower power settings, the aircraft can be flown at FAA speed limits probably get improved endurance and range.
The lightness of its mostly carbon-fiber airframe is formidable, but the star feature of the eG1 may be its software and human-machine interface (HMI). Its makers claim great safety benefits to software-assisted flight.
Improved Vision and Alerts
Alphafrog thinks much the same way as people like Sebastian Thrun, often named the father of self-driving cars. What’s the most dangerous part of the car? The driver. Likewise for airplanes, the pilot introduces errors the airplane would not make. (Of course, humans have been known to step in at awkward moments, ala Apollo 13, or that water landing on the Hudson River.)
Regardless, Alphafrog offers passive and active safety enhancements to improve flight safety. Pressing an emergency button on thek panel, “Will locate the nearest airfield and guide you to it using an ideal flight path, providing information for optimum airspeed and considering exact wind measurements.” This is similar to glide computers on competition sailplanes.
Alphafrog panel includes emergency switch which helps locate and guide pilots to the nearest field, GPS/GNSS (Global Positioning System/Global Navigation Satellite Sytem) provides options for obtaining signals from available navigation satellites
Passively, “a good damping gear and impact-absorbing seats,” and increased structural strength help protect the airframe and the pilot. Alphafrog offers pilot sustainability in a “70m² rocket-initiated parachute between the wings. We strongly recommend all aircraft be equipped with a rescue system, which has a proven record of saving hundreds of lives.”
The G1 comes with an angle of attack sensor (AoA) to prevent inadvertent stalls and a professional 100m range LIDAR system for ground collision detection. A surveillance upgrade uses, “High-resolution cameras to automatically detect flying objects that do not provide ADS-B or Flarm, and obstacles like wind turbines that have not been mapped.”
The electric motor has full redundancy, including double the coils, double the controller, and two or four batteries with their battery management for each battery.
Bigger Things in the Future
Sustainability comes in a bigger package, with the eG4, a light craft capable of carrying four passengers. Designed to meet MOSAIC (Modernization of Special Airworthiness Certification) standards, the airplane is meant to provide efficient travel for four at half the cost of more conventional machines.
Alphafrog eG4 features range extender hybrid power system, software package similar to that on eG1
“Equipped with a powerful, yet highly efficient, electric propulsion system alongside a small combustion engine range extender,” the eG4 should provide inexpensive travel while benefiting from an AI (Artificial Intelligence) flight control system. This should be an interesting airplane from an interesting company.