The age of the electric plane has dawned, but battery capacity and the COVID-19 pandemic are likely to delay its take-off By Mike Buckley, Log Board member ust over 116 years ago, Wilbur and Orville Wright launched the world into the first era of aviation. The second era the jet age began in August 1939, when the Heinkel He-178 made its maiden flight from Rostock, Germany. On 11th December 2019, we entered the third era, when Greg McDougall piloted the Harbour Air ePlane the first all-electric commercial aircraft, converted from a 62-year old DHC-2 Beaver floatplane, C-FJOS on its inaugural flight. That flight was just like flying a Beaver but it was a Beaver on electric steroids, recalls McDougall. Actually, the first manned electric aircraft to fly under its own power was in 1973, when two Austrians flew a converted motor glider for just 14 minutes. So, the idea of electric flight isnt new. The single greatest problem to date has been battery capacity, as Adam Crehan-Clark explained in a previous edition of The Log (Power Sharing, Winter 2020). Currently, the best battery energy density is around 270Wh/kg per cell (Tesla battery), but Elon Musk has calculated that this figure needs to be at least 300Wh/kg per cell to be competitive and more than 400Wh/kg per cell to match Jet A1-powered aircraft. Many different types of batteries and fuel cells are being looked at: lithium/sulphur batteries, aluminium/air cells, and hydrogen/oxygen fuel cells. US start-up Cuberg is developing a battery cell that combines a lithium metal anode, proprietary electrolyte and high-voltage cathode, to achieve high-energy density and thermal durability. Another problem with batteries is overheating. It is estimated that a thermal management system will need to dissipate between 50kW to 800kW of heat in flight. Cooling systems will be required for the integrated power modules used for high-power electronics, and materials will have to be developed for improved thermal performance, with a lightweight system to cool those electronics. To reduce weight and increase efficiency, superconductivity and supercooled electronics will be needed to reduce the electrical resistance of the aircraft. Hybrids and history-makers Perhaps the most radical design for a small electric aircraft is the one by Israeli company Eviation. The Alice will be a swallow-tailed aircraft, using three pusher props driven by individual magni250 (375hp) or Siemens (349hp) motors, and constructed of 95% composite materials. The motors will be supplied by a 900kWh lithium-ion battery pack, which will contain 9,400 cells spread all over the airframe. Made by South Korean firm Kokam, it will weigh around 3.8 tonnes about 60% of the aircrafts weight. The Alice is aimed at routes of around 565nm (650 miles), such as Paris to Barcelona, at speeds of up to 265kts. Sadly, the prototype Alice was damaged by fire in January this year, when a ground-based battery caught fire at Prescott Regional Airport in Arizona, where the aircraft was due to start flight testing. The magni motors are made by magniX, and are similar to the units that powered Harbour Airs ePlane. It is most likely that the first large, commercial passenger aircraft to enter regular service will have some form of hybrid power system, using a gas turbine to turn a generator to augment the batteries, thereby extending the range. In 2013, Boeing and Jet Blue started work with Zunum Aero to design and build a family of 10- to 50-seat hybrid electric regional aircraft. The first model, due to fly this year, will be a 12-seat airframe, using hybrid ducted fans powered by batteries and a generator producing up to 4MW. In 2017, easyJet announced it was partnering with Wright Electric to design a 180-seat shorthaul aircraft, for introduction in 2027. Harbour Air CEO Greg McDougall, left, and Roei Ganzarski, CEO of magniX That flight was just like flying a Beaver but it was a Beaver on electric steroids Click to see the Eviation Alice A flight in the Harbour Air ePlane Another hybrid design is the Starling Jet, by Bedfordshire-based Samad Aerospace, which has a similar configuration to the Alice and is due to fly in 2023. Using three tilting, hybrid turbofan diesel engines and two lift fans, the Starling has a blended wing body and will be capable of VTOL, cruise at 400kts and have a range of 1,300nm with up to 10 occupants. It will be aimed at business users, but could also be employed in disaster relief and offshore oil supply. This year should see the first flight of the ACCEL a joint venture between Rolls-Royce, YASA and Electroflight which aims to become the fastest electric aircraft in history, although it will be a single-seater. Rolls-Royce is also working with Airbus and Siemens on the E-Fan X programme, which will have a 2MW electric motor mounted on a BAe 146 jet, set to fly in 2021. The engineering is absolutely leading-edge, and our investment in electrification is ramping up rapidly, says Rolls-Royces chief technology officer Paul Stein. We should see the test flight of the Zunum Aero/Boeing machine as well. Rocking your world Greg McDougall, CEO of Harbour Air in Vancouver, and Roei Ganzarski, CEO of magniX, Seattle, are the driving forces behind the ePlane. Unveiled at the Paris Air Show in June last year, the Beavers propulsion system is the magni500, a high power density electric unit, delivering 280KW, or 375hp. The batteries are lithium-based and each cell is encased in protective material to prevent thermal runaway. The battery packs are placed under the floor, and the mass of the new system is roughly that of the Pratt & Whitney Wasp Jnr radial engine and its associated systems. The electrification programme continues Harbour Airs green credentials; in 2007 it became the first airline in North America to achieve carbon neutrality in flight services and corporate operations. The intention is for all of Harbour Airs fleet to be converted to electric power by 2022 but, first, it has to satisfy Transport Canadas certification regulations. Despite the COVID-19 crisis, the development teams at Harbour Air and magniX have forged ahead with the certification process; more test flights have been carried out and several systems have received upgrades, resulting in the approval of a new flight test plan, to include extended range performance tests. The first test flight under the new permit was on 20th April and more flights will be carried out during May. Going all electric will bring down the cost per flight hour by 60% to 80%, with the benefit of no CO2 emissions. As McDougall says: In business, you are either going up or going down. If we sit here looking out the window, one day there will be something out there thats going to rock your world. I want to be the one flying it, not the one watching it. After the first flight of the ePlane, Ganzarski said: Its not a race its a herd of horses running. The Harbour Air Beaver is the first one to do it; the Alice will be the first electric plane designed from scratch. There is still a long way to go before commercial, passenger-carrying electric flight becomes a common sight, and the COVID-19 pandemic will no doubt delay progress but it is coming. In 10 years time, you are going to see a transformation in transport, says McDougall. I hope you remember back to this day! The single-seater ACCEL aims to become the fastest electric plane in history The Alice the first electric plane designed from scratch E LEC TR I C F LI G HT Green-sky thinking