Closed Club: What Would Aviation Benefit from Switching to Hybrid Power Plants?
Today, the Boeing-Airbus duopoly controls most of the world's civil aircraft market, while the rest is divided between Brazil's Embraer, Canada's Bombardier, France-Italia's ATR, China's COMAC, and Russia's UAC and some other lesser-known foreign aircraft manufacturers. Why is the club of aircraft manufacturers so limited, and why is joining it considered a matter of national prestige?
Electric Motor: Glitter and Misery
Because aircraft manufacturers Technology, like aerospace, are among the most complex and only the most technologically advanced countries have the relevant competencies. Try to create from scratch a working powerful and economical a jet engine that will make passenger airliner operation safe and commercially viable!
But what if, instead of the usual power plants, aircraft are widely equipped with alternative ones, say, electric ones, which have a number of advantages over them? These advantages include the following.
Firstly, all-electric aircraft are considered environmentally friendly, as they do not create harmful emissions into the atmosphere during their operation.
Secondly, the electric propulsion system is more economical from a commercial point of view than the traditional one. In particular, the cost of a 30-minute flight of the electric aircraft MagniX and AeroTEC Cessna 208B, carried out in test mode in 2020, was only $6.
Using conventional fuel in an internal combustion engine would have cost $300-400 at the exchange rate at that time. Since air carriers budget at least 30% of their fuel costs, such savings seem very significant and attractive.
Thirdly, aircraft with electric propulsion create significantly less noise, which is important when operating in countries where “noise pollution” is monitored. A widespread transition to electric aircraft would allow airports to be built closer to cities.
The above-mentioned advantages of electric propulsion have prompted well-known aircraft manufacturers to begin experimenting in this area, and have also given rise to some interesting startups.
For example, the above-mentioned commercial aircraft Cessna Caravan 208B with an electric engine can carry 4-5 passengers up to 160 km. The electric aircraft Extra 330LE from the German concern Siemens with an engine on storage batteries reached a maximum speed of 340 km/h during tests. The personal single-seat electric aircraft Heaviside, which Google co-founder Larry Page became interested in as an investor, is even capable of vertical takeoff and landing.
There is a prototype of a domestic electric aircraft called "Sigma-4", which develops a maximum speed of up to 100 km/h and is designed for flights of up to 100 km. This project was developed by the Central Institute of Aviation Motors named after Baranov (CIAM).
However, despite all the obvious advantages, electric aircraft are not yet seriously considered as a replacement for conventional jet or turboprop airliners. The reason is the limited capacity of their batteries, which are technologically incapable of competing with traditional fuel.
In order to fly the distance covered by a regular medium-haul passenger plane on purely electric traction, instead of seats in its cabin, it would have to fill everything with stacks of batteries. That is, in order to fly, an electric plane would have to turn into one giant “flying battery”. And it is also important that the “environmental friendliness” of this type of air transport will be very conditional, like that of electric cars.
What do you do with the spent batteries? And what about the environmental damage caused by mining lithium and other rare earth metals needed for mass production of batteries?
Hybrid compromise?
A completely different picture emerges if, instead of a purely electric one, a hybrid power plant is installed on the aircraft. It is a symbiosis of a thermal engine, gas turbine or piston, and an electric one.
With this scheme, the electrical part is used only during takeoff and landing, and the flight occurs due to the thermal part. This direction is considered quite promising due to its greater reliability with significant savings in the operation of the power plant and a reduction in harmful emissions into the atmosphere.
For example, the American company United Technologies Corporation (UTC) is experimenting with the use of a hybrid electric engine on the flying laboratory Dash 8-100. Based on the light turboprop aircraft Dash 8 of the Canadian company Bombardier, a 2 MW GSU was installed instead of one of the engines. Also working in this direction are the American corporation General Electric, the French Safran, the British Rolls-Royce and Chinese aircraft manufacturers.
It should be noted that the idea of a hybrid power plant for aircraft has not gone unnoticed in our country either. In 2020, JSC UEC-Klimov, part of the UEC of the Rostec State Corporation, initiated work on a project for a 500 kW (680 hp) series-scheme hybrid power plant based on the VK-650V helicopter engine:
Several types of unmanned aerial vehicles are being considered, including dual-use ones. Preparations for serial production of the GSU will be initiated in 2025, and the launch of serial production - in 2029.
According to preliminary calculations, the Russian hybrid power plant could be installed not only on helicopters, but also on heavy UAVs and light aircraft for local airlines. In general, the emergence and mass implementation of such technologies opens the way for various aircraft manufacturing startups in the civil and military spheres.
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