The Problem with Zero-Emission Airliners

Zero-emission airliners could help the aviation industry deflect environmentalist attacks, but they risk undoing decades of progress in speed, capacity, safety, and convenience.

The aviation industry is under relentless assault from environmentalists. Protesters have attacked and invaded airports, activists such as Greta Thunburg have told people they should feel ashamed every time they fly, and governments around the world are levying charges or even imposing outright bans to try to reduce how many flights people take.

All this is happening despite the fact that aviation is a massive force for good that enhances human life in countless ways. It connects people across international borders, ferries freight around the world, aids disaster recovery, and opens up experiences and opportunities for people all over the planet. Rather than proudly exalting these benefits and defending aviation as a moral good, most major airlines instead join the chorus of their attackers. They frequently remind passengers of their flight’s carbon emissions, forego service upgrades in order to fund environmental projects, and even, in the case of KLM, give passengers a “consider your options” message when booking, asking them to think about driving or taking trains instead of flying. 

Sadly, it seems that both governments and the wider culture are not going to change course any time soon. The aviation industry is looking at a future of more government restrictions and more campaigns to stop people from flying. It’s a bleak picture, but some think there may be a ray of hope for the industry: newly developed zero-emission aircraft. 

Several start-ups are currently working to develop zero-emission aircraft that could, if successful, provide a means for the aviation industry to survive and grow in spite of environmental regulations. For example, in Sweden, Heart Aerospace is developing a thirty-seat regional airliner powered by four electric propellers. In the United States, Wright Electric is converting BAE-146 regional jets to electric power. And in the United Kingdom, ZeroAvia is developing hydrogen-powered aircraft for short-hop journeys. These aircraft are “zero-emission” in that they produce no emissions when operating, although emissions may still be involved in electricity generation and hydrogen production.

Unfortunately, these aircraft all share the same two problems: Short range and low carrying capacity. And this is a direct consequence of the fact that they are relying on “green” forms of propulsion that are less efficient and less powerful than traditional engines. Fixed-wing aircraft work on a simple principle: The faster an object moves through the air, the more force its interaction with the air generates. For a large, long-range aircraft to get airborne, it needs to be moving fast enough for the air passing under and over its wings to generate the large amount of “lift” needed to pull the plane into the air. In practice, most planes take off well before they’ve reached this speed, rotating on the runway to angle their engines downwards to provide extra vertical thrust (without this, runways would have to be several miles long). 

In short, large aircraft rely on the tremendous power of their engines both to achieve the high speeds necessary for sustained flight, and to get off the ground in the first place. Engines that do not produce jet thrust cannot (currently) produce anything like the acceleration and force needed to do this.

That is why all of these zero-emission aircraft are small, short-range vehicles: Their engines lack the power and efficiency for moving large masses at high speeds over long distances. These aircraft cannot match the performance of small regional jets of comparable size. Add in the weight of batteries, and the result is an aircraft with less range and capacity than a propeller-powered regional plane. In all-electric mode, the four-engine Heart Aerospace ES-30 will have a range of 125 miles (250 miles in hybrid mode), seating a maximum of thirty passengers. For comparison, a two-engine turboprop-powered ATR-72 carrying seventy-four passengers can travel 930 miles, and a two-engine jet-powered Embraer-175 carrying seventy-eight passengers can travel 2,531 miles. Both the ATR-72 and the Embraer-175 are small aircraft designed for local flights and are typically the smallest, least powerful planes in airline fleets.

In spite of these shortcomings, several major airlines have placed large orders for Heart's electric’s ES-30, including United Airlines and Air Canada (the latter has also bought a sizable stake in the company). If these airlines were to replace only the smaller aircraft in their current fleets with ES-30s, the result would be a massive step backward for passengers and carriers alike. Many journeys currently made in one flight would require connections or stops to recharge, and multiple aircraft and crews would be needed to service routes that one aircraft can currently handle on its own. They would be less economical and less convenient. For example, Air Canada’s 414-mile route from Halifax to Boston, currently operated with one fifty-two-seat Bombardier CRJ-200, would require two ES-30s, each needing one refueling stop in hybrid mode or four recharging stops in all-electric mode.

Because these aircraft have been designed to assuage environmentalists, not to produce a better product for customers, the results will be worse for the industry and worse for travelers. They will undo the progress of the jet age and take air travel back to the 1950s, when a long flight involved multiple stops and starts on small, slow-moving propeller planes.

These new aircraft do not make any commercial sense. They exist for two main reasons: (1) they have received government funding, and (2) airlines and investors are keen to appear concerned about climate change.

Heart Aerospace grew out of a Swedish Government research program. Wright Electric receives funding from NASA, the U.S. Air Force, and the U.S. Army. ZeroAvia has received grants from the British Government. In funding these projects, governments are using coercion—forcibly taking money from people to be spent whatever way the government thinks it should be spent, regardless of people’s individual priorities or commercial incentives—to push the industry away from what its customers actually need. The result is products designed to achieve a government objective (which is born out of a desire of politicians to satisfy voters and get reelected), not one designed to satisfy a commercial need and provide better transportation.

Similarly, the money these projects have received through orders from airlines does not stem from the commercial attractiveness of the product. United Airlines, a company that, in the 1950s, invited customers to “Come Fly the Friendly Skies,” recently announced its new tagline “Good Leads The Way,” reflecting the company’s goal of making “historic investments to fight climate change.” This sounds like a company more interested in virtue signaling than one focused on providing a good service for passengers and a healthy return for investors. EasyJet, the lead customer for Wright Electric’s proposed Wright 1, boasts that it offsets all of the carbon produced by its planes at no cost to the customer—meaning that large amounts of the company’s revenues are going into planting trees instead of improving services for those customers. Wright and EasyJet have prematurely announced that the Wright 1 will enter service in 2030 and boast a capacity of 186 passengers and an 800 mile range, despite the fact that Wright has yet to successfully fly its BAE-146 conversion with even one electric engine.

All this isn’t to say that designing low- or zero-emission aircraft isn’t an admirable goal. The point is that such a goal should not come before designing an aircraft that improves the passenger experience, improves the airline’s efficiency, and competes effectively with existing designs. The purpose of an aircraft manufacturer is to produce the best product for transporting people as quickly, comfortably, and cost-effectively as possible. Some companies have produced, or are producing, aircraft that achieve this balance well. The new Airbus A220 (originally developed by Bombardier as the C-Series) is a cutting-edge jet that delivers a smoother ride, produces less noise, consumes less fuel, and offers a more comfortable interior than the aircraft it’s replaced at carriers such as AirBaltic and Delta Airlines. AirBaltic’s A220s produce 20 percent less CO2 and 50 percent less nitrous oxide than the Boeing 737s they replaced, while also improving the airline’s operational efficiency and revenues, allowing it to start new routes from its Latvian base to faraway destinations such as Abu Dhabi.

Another good example is Boom Supersonic. The company’s primary goal is producing an aircraft that will slash long-distance journey times, helping the industry get better at doing what it does best: connecting people across the globe. Producing a greener, more efficient aircraft is a secondary goal for Boom, one that goes hand-in-hand with producing a product that will be efficient and popular with customers. It is not the driving factor behind the aircraft’s design. That is why Boom’s product will, if successful, be a futuristic wonder that will usher in a revolution in how people travel, whereas the Heart ES-30 will have less range and capacity than a 1930s Douglas DC-3.

The work that companies such as Heart, Wright, and ZeroAvia are doing is advancing some areas of aviation technology, and on some level, that’s good to see. The industry has suffered a drought of innovation since the jet age of the 1960s, when revolutionary designs such as the Boeing 707 and 747 brought a transformation in range, speed, and capacity that has hardly been improved upon since (the 747 has only just ended production, fifty-four years after the type debuted). That dearth of progress was caused by exactly the kind of government intervention that is now pushing aircraft design backward with projects such as the ES-30. For decades, innovation in more efficient two-engine long-range aircraft was held back by an outdated regulation requiring transatlantic flights to have at least three engines. Development of supersonic airliners such as the ones Boom is now developing has been held back since the 1970s by restrictions on their use over land. On top of restrictions such as these, governments around the world have used phenomenal amounts of money and coercive appropriation of land to construct nationwide highway networks, which removed commercial incentive to develop better short-haul air travel by making driving more attractive as an alternative.

Every piece of technology has a purpose. The purpose of an aircraft is to provide fast, efficient transportation, and in serving this purpose, they greatly enhance human flourishing. The more that companies and investors confuse that and elevate the government’s environmental goals over their primary function—producing aircraft that are more about being zero-emission than providing effective transportation—the more the industry will suffer, and the more human flourishing will suffer as a consequence. Although it is commendable that innovators are trying to find ways to help the aviation industry survive the onslaught of environmental restrictions it’s facing, producing aircraft that are massively inferior to the turboprops and jets they’ll be replacing is not the way forward.