electric aircraft: boom or bust?
September 12, 2019
More electric and all-electric aircraft are gaining momentum as more and more companies are investing in technologies that enable these types of power systems. With a huge number of projects on the drawing board, the question has changed from will we see electric aircraft to when will they take-off? Volker K. Thomalla explores
Is electric flight the next big thing in aerospace? Considering the huge number of projects of electric-powered aircraft and unmanned aerial vehicles, electric flight should be a significant part of the future of aviation – including Business Aviation. But there is already skepticism about the maturity of technology and the availability of new materials for on-board storage of electric energy.
As of today, there is no project or concept capable of replacing existing business aircraft in terms of range or speed. The energy density of even the most sophisticated batteries are simply not able to power long-range flights of all-electric aircraft. Nevertheless, nearly all major aerospace companies, including Boeing, Airbus, Embraer, Rolls-Royce, Honeywell Aerospace, Safran and United Technologies, are working on concepts and projects to advance electric flight. And there is a huge number of start-ups, backed by venture capital, who are trying to get a foothold in the not-yet-existing market for electric powered aircraft.
Countries are also getting on board. For example, Norway launched an initiative to replace conventional, fossil fuel burning aircraft with electric-powered aircraft for all short-haul flights by 2040. “We aim to be the world’s first to switch to electric powered air transport,” says Dag Falk-Petersen, CEO of Avinor, Norways airport authority. “We believe that all flights lasting up to 1.5 hours can be operated by aircraft powered exclusively by electricity, and this flight time is sufficient for all flights within Norway and to neighboring countries.”
Avinor wants to publish a tender for a test operation with a 19-seat commuter aircraft. Its aim is to test an electric aircraft under real conditions from 2025 on in daily flight operations. “When we reach our goal, traveling by plane will no longer be a problem for the climate,” adds Falk-Petersen. “On the contrary, flight will be part of the solution.”
The Grid and P804
In April this year, Collins Aerospace Systems, a unit of United Technologies Corp. (UTC), revealed plans for The Grid, which is to become the industry’s most advanced electric power systems lab. It will be based in Rockford, Illinois, and should be operational in 2021.
To build The Grid, Collins Aerospace needs to invest about US$50 million in the building and supporting infrastructure. The company will use the high-power, high-voltage lab to design and test systems like high-power generators for the next generation of electric aircraft, including commercial, military, Business Aviation, UAV and urban air mobility platforms.
Collins Aerospace CEO Kelly Ortberg is convinced that electric power systems will shape the future of aviation. “In the not-too-distant future, hybrid-electric and fully electric aircraft will revolutionize air travel as we know it—opening up new markets like urban air mobility, while re-invigorating others like regional service to underutilized airports,” he says. “They will help support a greener planet by reducing carbon emissions and will help our airline customers by reducing operating costs and fuel consumption.”
The Grid will be used to help design and test a 1 megawatt motor, motor controller and battery system. The goal is to design and build the aviation industry’s most power-dense and efficient electric engine to date. The motor is needed for Project 804, which is being developed by UTC’s newly established subsidiary United Technologies Advanced Projects (UTAP). UTAP aims to innovate faster than the Group has previously been able to do. One of the first UTAP projects deals with the implementation of a hybrid electric power system for regional aircraft. The project, named Project 804 (P804), aims to fly an aircraft with such an engine within the next three years.
Despite its high number, Project 804 is the company’s first project. The number was chosen because it represents the distance in miles between the two corporate sites in Montreal, Canada, and Rockford, Illinois. In March this year, UTAP presented P804 to the public for the first time. As a test aircraft, the company has selected a used Bombardier Dash 8-100 turboprop aircraft with the turboprop engine on the right hand side being replaced by a hybrid electric drive.
The new drive alone should have the power of 1 Megawatt. It will be optimized for cruise and is supported by a battery-powered electric motor during take-off and climb. While the new drivetrain will increase the aircraft’s operating empty mass, in return, the tank capacity can be reduced by 50%.
According to UTAP scientists, the range of the aircraft will be around 600 nautical miles (1,111 kilometers). Although this is less than the range of the aircraft today (1,000 nautical miles / 1,852 kilometers), since most regional flights are on average shorter than 500 nautical miles (926 kilometers), the mixed cost makes sense, both from a technical and from a business point of view.
UTAP estimates that the experimental aircraft consumes approximately 30% less fuel than previous aircraft in a typical one-hour flight of a regional aircraft. The batteries and drive control of the new system must be housed in the aircraft cabin, while all other system components fit into a modified Dash 8 engine nacelle.
The Future of Flight will be Electric
Honeywell Aerospace is very much engaged in the development of electric power systems for aerospace applications, too. The company is convinced that the future of flight will be electric and that very soon aircraft will fly safely, quietly, efficiently and cleanly powered by electric and hybrid-electric engines.
With this philosophy, the company has assembled a dedicated Hybrid Propulsion Team and renowned global engineering staff who are driving the science of hybrid-electric propulsion forward, producing turbo-generators, generators, motor controllers and other essential powertrain elements. Honeywell offers a broad range of aircraft power generation solutions to deliver electric power, from 5 to 200 kVA, in different configurations. The Phoenix, Arizona, based company introduced the industry’s first 1 MW generator for aerospace applications.
Another player in the field of electric aviation is the Israeli start-up company Eviation. Its co-founder and Chief Executive Officer Omer Bar-Yohay has presented a soon-to-fly prototype of Alice at the Paris Air Show in June. Alice is a battery-powered, electric aircraft about the size of a Beechcraft King Air. According to Eviation, Alice is capable of transporting up to nine passengers at a speed of 340 knots over a distance 540 nautical miles with a single charge of its lithium-ion batteries.
The futuristically shaped Alice is powered by three electric engines. One sits in the rear of the aircraft and drives a five-blade Hartzell propeller, while the remaining two (smaller) engines are installed in the wingtips and drive a five-bladed prop form Hartzell. Alice’s wingspan measures 16.12 meters, the maximum take-off weight is about 14,000 pounds (6,350 kilograms), of which the batteries alone use 8,160 pounds (3,700 kilograms). Avionics and the fly-by-wire system for Alice will be supplied by Honeywell Aerospace.
Alice is built entirely of carbon fiber composites. Eviation is planning to ship the prototype to the US where flight testing should take place. The company will use three aircraft for flight testing. It is targeting a two-year test and certification campaign, with entry-into-service in 2022.
At the Paris Air Show, Cape Air, was announced as the launch customer for the aircraft. The company currently operates a fleet of Cessna 402C business-liners and Britten-Norman BN-2 Islander, which need to be replaced in the foreseeable future.
Change of Plans
But not all high-flying projects will really take-off. Zunum Aerospace from Kirkland, Washington, has plans to develop aircraft with hybrid-electric engines. They had targeted an entry-into service of the first aircraft, a five to 12 seater, as early as 2022. The company even won support from companies like Boeing (via their innovation subsidiary Horizon X), JetBlue’s Technology Ventures and Safran Helicopter Engines (Safran was the chosen partner to supply the power system of the ZA10 aircraft). It was planned that the first tests with the power system based on the Ardiden helicopter engine should take place on board of a Rockwell Turbo Commander aircraft.
But sometimes plans don’t workout. Zunum Aerospace ran into financial troubles and had to lay off the majority of its staff in early summer. The company said it remains committed to the technology and the future of electric flight. “But unless new investors step forward, that fanciful dream is dead,” reported the Seattle Times in July this year.