When you think of air taxis, what do you picture? A prosaic Jetson’s traffic jam in the sky, or a bleak Blade Runner dystopia?
The Aviation Green Paper released today for public feedback anticipates ‘emerging aviation technologies’ like drones and advanced air mobility (AAM) could triple aircraft movements – particularly in urban areas – with implications for noise, privacy and community acceptance.
“In short our skies will become busier,” the paper observes. The paper projects around 37 million passenger trips by AAM – or air taxis – by 2050.
“This would lead to a significant change in the way Australian airspace is managed, as well as noise and amenity impacts felt by communities.”
Electric delivery drones are already active in Queensland and Canberra. And now industry is pushing to make the science fiction of passenger aviation a reality, with plans for electric aircraft flying between the tops of buildings and urban transport nodes like airports and train stations.
But first these emerging aviation technologies will need to contend with the real world concerns of regulation, planning, noise and safety, along with the community’s own hopes and dreams for their cities (which may or may not include more aircraft movements).
Community engagement
Australian National University’s Professor Sara Bice has undertaken Australia’s largest study into community engagement for infrastructure, but says there are few case studies comparable to the consultation required for an entirely new and unprecedented use of airspace in the form of air taxis or advanced air mobility (AAM) to get off the ground, she says.
AAM combines the use of new aviation technologies (generally electric), new infrastructure (vertiports) with scaled up operations – more flights, routes and landing sites – transporting thousands of people and/or packages at low altitude within and across densely populated urban areas.
Often badged as a futuristic idea, various proposals for air taxis in Australian cities expect the idea to take off this decade. For example, Wisk Aero and Queensland mayors plan to deliver air taxis in time for the 2032 Olympics, while Uber Air, followed by Eve and Microflite announced plans for an air taxi service in Melbourne.
But before industry and governments get too carried away with the idea, there is important public engagement work to do, Bice says.
“When we introduce new technologies, ensuring there is a really open, robust and usually long-term conversation – which involves education about the new technology – is absolutely critical.”
Given the concept involves a completely altered use of a shared resource – the sky – the closest equivalents might be attempts to regulate the seas, or share use of the Earth’s outermost atmosphere for satellites.
“There’s a very important broader question about whether this use of a shared resource – our sky – meets community expectations for what should be happening?” she says.
That’s a considerable challenge, but community education, consultation and relationship building is only part of the major system changes needed for AAM to take off.
Planning
The regulation of airspace and aviation is already complex in Australia, with responsibilities spread across numerous departments and authorities at Commonwealth, State and local government levels.
In general terms, the Commonwealth is mainly responsible for what happens in the air, while states are mainly responsible for what happens on the ground via their land use planning systems.
Yet aircraft – including new proposals like AAM – operate across both domains.
There’s a very important broader question about whether this use of a shared resource – our sky – meets community expectations for what should be happening?
Professor Sara Bice
Since 2012, the Commonwealth, states and territories have agreed to the National Airports Safeguarding Framework, which aims to improve community amenity by minimising noise-sensitive developments near airports and improve safety outcomes by ensuring aviation safety requirements are recognised in land use planning decisions.
In her 38-year public service career, Marianne Richards gained extensive knowledge and experience in port, airport and freight network planning across all layers of government.
She explains that at the Commonwealth level responsibilities for aviation are shared between 3 bodies: the Department of Infrastructure, Transport, Regional Development, Communications and the Arts advising on policy and regulation; the Civil Aviation Safety Authority which regulates safety; and Airservices Australia which manages the airspace.
Planning for AAM is covered through a series of strategies, roadmaps, partnerships and frameworks.
One element, the Infrastructure Planning Framework aims to ensure a nationally consistent approach to infrastructure and planning decisions for AAM, drones and other emerging aviation technologies.
Ultimately state or local governments will be responsible for decisions about landing sites, and infrastructure called vertiports (similar to a heliport, for landing new aircraft and may be located on top of buildings). Richards says to help state and local governments in their decision processes, it will be important to include AAM infrastructure and operating standards into the National Airports Safeguarding Framework.
Unlike environmental impact processes for major developments on land, there is currently no overarching planning process – in Melbourne, or Brisbane or other places where air taxis are proposed – for informing and engaging with the Australian public about AAM, to describe its scale and impacts, and provide an opportunity for citizens to accept or reject the idea.
Noise
The Aviation Green Paper says: “The deployment of new technologies such as drones and AAM, while not as loud as larger aircraft, will also raise noise issues given the low altitudes and proximity to residential areas at which they operate”.
A White Paper on aviation noise impacts prepared by internationally-recognised experts for the International Civil Aviation Organisation says “new aircraft technologies for increased mobility are likely to lead to new sources of community noise”.
There is very limited research on community perceptions to noise from AAM the paper says, however it summarises a NASA study finding noise from smaller electric aircraft “is more annoying than noise from road vehicles when presented at the same loudness”.
A Deakin University brief on AAM noise issues released under Freedom of Information, says noise pollution associated with the wide-spread use of AAM will be a critical issue from a technical, regulatory and community perspective.
It says reactions to small-scale trials in Europe have been neutral or positive. “However, there is likely to be major community concerns to the full-scale onset of [urban air mobility], particularly when there are several thousand flights daily in a single urban location,” the brief says.
Complainants […] often express confusion when trying to find out who is responsible for regulating aircraft noise and anger at what appears to be a general lack of regulation.
Aircraft Noise Ombudsman
Alex Morabito, an acoustic engineer and Senior Associate at consultancy firm, Marshall Day Acoustics, says the primary way aircraft noise is currently managed in Australia is through land use planning around airports.
“So that’s looking at how often aircraft are flying in and out of an airport, setting relevant noise buffer zones called Australian Noise Exposure Forecast (ANEF) maps that are incorporated into local planning schemes to prevent or restrict certain types of noise sensitive development in close proximity to an airport.”
Under existing systems, an airport (usually on Commonwealth land) is responsible for creating ANEF maps,but is not responsible for managing or regulating noise or development around an airport.
That responsibility falls on the local land use planning system – usually a state or local government responsibility – by limiting development within certain zones.
The system only works proactively, setting limits on future development around airports, rather than applying retrospectively to existing uses, like houses, parks or schools.
Morabito says this means proposals like air taxis – usually conceived as being planned for existing cities like Melbourne or Brisbane – will require objective acoustic testing, and new standards to model and manage the anticipated noise levels resulting from unprecedented numbers of low altitude flights across urban areas.
The Aircraft Noise Ombudsman writes: “complainants […] often express confusion when trying to find out who is responsible for regulating aircraft noise and anger at what appears to be a general lack of regulation.”
Safety
Turbulence and wind gusts are a leading cause of air accidents, and affect aircraft of all sizes, say RMIT researchers.
AAM proposals are at greater risk of turbulence and collision due to a combination of factors: large numbers of light aircraft, low altitude flights and the complexity of urban buildings and infrastructure.
Collision risks increase as greater numbers of vehicles seek to navigate complex environments.
Publishing in Drones, the researchers say to address the risk of accidents, turbulence should be a key consideration in aircraft certification and the design of vertiports (landing sites).
And more
The challenges involved in getting air taxis off the ground from a community engagement, planning, noise and safety perspective are immense, but are only the beginning.
Social equity, environment, embodied emissions, privacy and security are among the other issues needing to be addressed.
Bice thinks given the complexity of what’s being proposed, governments will need to step in to facilitate discussions around access to airspace, visual amenity, noise, safety and how this new industry would be regulated.
Importantly, she adds, communities should be asked whether they want the change at all.
“What is going to be really important to this conversation, is ensuring that community members not only understand and have an opportunity to participate in consultation, but that these things aren’t introduced as a fait accompli. And indeed, that there is an opportunity for people to say no.”