Russia Presents Nearly Silent Hydrogen Model at MAKS 2019

 - September 3, 2019, 12:01 PM

Russia presented its first environmentally friendly and almost silent manned aircraft with hydrogen thrust during MAKS 2019 airshow. That was the two-seater aircraft, dubbed Sigma-4. Its wingspan will be 9.8 meters, while the length is approximately 6.2 meters. The aircraft will also have a takeoff weight of 600 kg and a flight range up to 300 km.

The new Sigma-4 became a joint development of scientists of the Russian Institute of Problems of Chemical Physics and engineers of the  Baranov Central Institute of Aviation Motors, while its distinguishing feature is a power cell, which converts the energy of the reaction of hydrogen with oxygen without burning into electricity.

According to engineers, the hydrogen in the engine is not burned but enters into an electrochemical reaction with oxygen, ensuring electricity supply to propellers. The aircraft is 100 percent environmentally friendly, as it discharges vapor instead of exhaust gases, into the atmosphere. The energy efficiency of a hydrogen powerplant is 2.8 times higher than one burning kerosene.

As designers of Sigma-4 have said, the new aircraft will be recommended for the use for the needs of agriculture, as well as air medical service. In addition, it could be used as an air taxi. The hydrogen fuel cells, which are used in the design of the aircraft could be applicable to any other means of transport: from ships and all-terrain vehicles to mass vehicles and household appliances, including gadgets.

In the meantime, Russian analysts in the field of aviation consider the new project promising, but they believe that further development of hydrogen aviation both in Russia and on a global scale will mainly depend on the availability of needed infrastructure for such aircraft, primarily refueling stations. 

In fact, the development and testing of hydrogen-fueled aircraft took place in the USSR during the 1980s as part of the Holod-2 program. At that period the Tupolev bureau designed the trimotored Tu-155. One of the three engines of that aircraft operated on liquid hydrogen.

Still, despite some undeniable advantages of the new aircraft, Russian analysts remain rather skeptical, regarding the prospects of the new aircraft and its other hydrogen-based analogs.

Oleg Panteleev, head of analysis at  Aviaport, one of Russia’s leading analysts agencies in the field of aviation told AIN Sigma-4 could be primarily considered an experimental aircraft at least at the initial stage.

He said, "In recent years some small unmanned aerial vehicles that use hydrogen to generate electricity in fuel cells have been designed in different countries of the world, including Russia. Even in the case of the design of safe and economical hydrogen-based aircraft, it will unlikely replace traditional aircraft that use kerosene at least in the near future. This is mainly due to the lack of infrastructure for the production, transportation, storage and refueling of hydrogen, as well as powerful electric motors that could rise a heavy aircraft into the air. That means the newly developed Russian aircraft will be primarily used for regional flights."

According to Panteleev and other leading Russian and foreign experts in the field of aircraft manufacturing, serial production of such aircraft could be profitable only in the case of the design of powerful electric motors. 

According to Panteleev, in regard to Tupolev, the company has already been involved in creating a hydrogen fuel propulsion system in the past.