I developed this concept as part of a client engagement last year. It’s been rattling around in my brain since then, and I’m writing this here because while it’s very clear to me, I’m not sure I can make it clear to everyone else.
The client engagement was around imagining future development of civil aviation, and led to the idea of the British Eagle, the Lego Brick Airline. The Lego Brick Airline is an airline which operates as a combination of capabilities which can be sourced from a variety of providers, none of which need to be otherwise organisationally connected.
One of the things British Eagle, our fictional Lego Brick Airline (which I will stop talking about now), could do was change airports easily based on a competitive market in takeoff and landing slots. The customer doesn’t care what airline they fly out of as long as they get from their home/office to their destination on time, so there can be a live market in slots based on availability and demand, facilitated by handy tech. In the morning, or at the beginning of the week, or right before takeoff, somebody (or some AI) in the flight ops capability at the airline determines the best airports to fly from and to, and buys the slots from a menu of options.
I’ll get to the hydrogen, I promise.
If there is a small number of potential airports, there is a small number of potential slots, so the menu of options isn’t huge. If you’re getting from your headquarters in an office park in Leatherhead near London to a client’s headquarters in an office park in Stamford near New York, how many airport options do you have? (A lot, actually, compared with less airport-rich markets, but maybe not enough to create meaningful competition.)
So one of the things that would facilitate this way of working would be more airports. Of course there are regulatory barriers to this, as well as technical issues like runways and noise and getting passengers to the actual aircraft. A lot of the answers to these issues come from other parts of the Lego Brick Airline, but some of them are directly related to fuelling,
In many places ( London, Berlin) the idea of the newer, bigger airport has been a powerful and controversial one. In this scenario, we are imagining a different powerful, controversial idea: lots of small airports.
Here we come to the hydrogen.
The civil aviation industry is attempting to move to net zero carbon emissions at a fairly brisk pace. This means that instead of burning tonnes of hydrocarbon to make the aircraft fly, there is an urgent move towards burning something that hasn’t got carbon in it. Using hydrogen as a way to pack a dense load of energy onto an aeroplane is taken seriously as a model, and it doesn’t necessarily need to combust in order to work. Barring the potential of a Hindenburg-scale disaster, it’s a credible model.
Safely storing and moving hydrogen is, however, far more difficult than storing and moving current jet fuels. Whereas major British airports have fixed pipeline infrastructure to supply them with jet fuel on tap, keeping them supplied with hydrogen is a more difficult proposition. If we imagine producing, storing and distributing hydrogen the way we currently refine, store and distribute Jet A, we have to imagine a vast capital cost to create and instal a very different and more expensive set of systems to deliver hydrogen.
I have read think pieces on the future of civil aviation which have assumed that hydrogen needs to be distributed either by pipeline or by road/rail tankers. (These same think pieces often assume we would apply the same loading models as we use to make hydrocarbon-fuelled air travel profitable, and they are very ready to assume that future aircraft are about the same size and scale as the aircraft we used before the Pandemic.) If we manufactured and transported hydrogen as a gas, or as a liquid, then we might indeed still be stuck with giant airports and giant (or giant-ish) aircraft.
Thing is, hydrogen is dangerous and expensive to store and transport as a pure gas or liquid, but very abundant and safe to transport as water. (Safe compared to compressed hydrogen gas: water in quantity can cause damage.) Many countries have sophisticated water transport infrastructure, others have unsophisticated but vast rivers and streams full of the stuff. In order to have hydrogen ready to use as a mobile store of energy, we only need to ensure that airports have adequate supplies of water, a means of purification to a certain useful level, and a source of ample energy to crack the hydrogen out of the water and put it safely into the aircraft.
So here is my vision of a future airport.
(Call the year 2040)
The aircraft parked on the pan are smaller than we’re used to. The loading factors which make them profitable to run are different from the ones we’re used to, and while cargo airlines and developing world airlines are still running jumbo jets powered by kerosene, developed world airlines have got a lot more compact.
The runway or runways look a lot like the ones we have now, possibly shorter because technology enables us to effectively use shorter runways; possibly because the aircraft are smaller.
The buildings look about the same from the outside, but inside they are far more utilitarian. Passengers are not expected to go into the buildings at all, except in emergencies. They are dropped off by electric vehicles — perhaps quiet little e-VTOL fliers that move to the airport in the same controlled corridors as electric cargo drones. The passengers have finished check-in, security and immigration control on their way, and they go from one aircraft to another without going into a building. If there’s any need for a customs hall and a meeting point, it’s not at the airport, because the airline only booked into that airport this morning. Getting from the airliner to a customs centre — when required — or to a pickup point is a ground services solution.
The one thing the buildings might have would be nice toilet and shower facilities, because passengers who have just spent a few hours in an aircraft — whatever kind of aircraft — need a pit stop.
There’s no big car park for staff either. Local people might drive and charge their cars at the airport, but most staff (ops staff, ground staff, air crew, cabin crew) come to work the same way passengers arrive: remotely-controlled e-VTOL fliers.
The charging stations for e-VTOLs or ground transporters aren’t at the airport; they’re somewhere else, along with maintenance and cleaning facilities. The buildings mostly contain cold storage for food and drink, tanks full of lubricants, racks of pre-positioned spare parts, and emergency services equipment. People often imagine that air traffic controllers are in the tops of control towers, but they aren’t: they’re in light industrial parks or office buildings, miles away. Maybe there are still ground controllers in a tower, with a break room.
The shopping mall aspect of the airport used to be a profit centre back when people used to shop in person, and back before customs officials were able to use barcodes and other tech to trace the origins of high-value luxury items. Now there’s a different wheeze to take money off of prosperous travellers and use it to fund air travel facilities, and it’s even better than having a Rolex boutique and an Hermès shop. (Don’t ask me what the wheeze is; this is about fuel, not luxury retail.)
There’s one other thing in those buildings: the fuel plant, because the airport makes its own fuel.
In the Middle East, the water supply is grey water which comes from the drains (but not the sewers) of a nearby town or a nearby factory. In England or Canada the water supply is a local river. All these little hydrogen-based airports are built along reliable water supplies. Water moves through whatever filtration of purification is required, and into storage tanks.
At appropriate moments an electric cable powered by local electricity (very sustainably sourced in some countries, less so in other countries) powers a cracking station which produces compressed hydrogen gas (which goes into some type of stored form on the aircraft, not necessarily just a pressure bottle), and compressed oxygen gas (which is sold to local welders and hospitals, not necessarily in that order).
The energy input for the cracking station is electricity from a national or regional grid. For the purposes of this discussion, the grid is very reliable, and has overwhelmingly renewable inputs, with massive nuclear power stations still operating in case of loading spikes, and because it is cheaper to keep them operating than it is to decommission them. The cracking station draws fairly predictably, and no more than any light industrial facility might. The electricity transmission vendor has built extra redundancy into the connection because of the terms of the service level agreement, but this is just another commercial customer drawing from the grid.
Long-distance electricity transmission isn’t the only way to move energy long distances. Cities used to have mains compressed air before everything was electric. Some cities still have mains live steam, because electricity isn’t everything and copper wire can be expensive. If national grids go over to some other means of transmitting energy, there might need to be a converting station to turn live mains plasma into electricity, or maybe you can crack hydrogen with live mains plasma. That’s a problem of engineering and cost accounting.
Sometimes there is a technical probem, and the fuel manufacturing process isn’t working. It might be best to truck some compressed gas over from a nearby facility. It might be best to phone for a mobile filtration truck and a mobile cracking truck to come and do the work. (Maybe the regular cracking station is on a mobile platform anyway, and the kacked facilities are driving off to be repaired at the same time.) It might be best to switch operations over to another airport: airports this small, stripped-down and environmentally friendly are all over the place, and the whole point of them is that they’re interchangeable. (In my mind the hydrogen-powered aircraft are not only carbon-neutral, they’re also quiet. Grant me this.)
Of course there was environmentalist opposition to creating this airport from a long-disused wartime airfield, or a minor local general aviation facility. The environmentalist opposition was locally right, that their quality of life might be negatively impacted by air operations. The local bird population would definitely bear some impact. Opposition to this facility might even be globally right: thermal pollution from hydrogen-powered aircraft would still create long-term environmental impact. Maybe the hydrogen-powered aircraft wasn’t the great environmental boon people had expected. This only addresses greenhouse-gas-driven climate disaster, not other problems of human impact on the planet. We can’t expect technology to save us from tough choices.
This airport isn’t there forever, though. Sometimes it’s economically easier to fly somewhere else. Fashions change. Ski season ends. The place is shut down. A security contractor locks the doors. The electric people-movers fly the staff to a different work location. The electric e-VTOL fliers bring the passengers to the other facility. The caterers bring the meals there. If it’s going to be a seasonal shutdown, the infrastructure remains in place. If it looks as though the location is long-term unprofitable, the buildings are disassembled and put back together somewhere else.
There’s a version of this for a deeper future, with smaller, slower aircraft flying some routes while smaller, hypersonic aircraft fly other routes. (Smaller aircraft are one of the themes here, because hydrocarbon-based loading models are being chucked out the window). The rest of the aerospace ecosystem fits into this, with remotely-controlled or autonomous cargo transporters flying in nearby air lanes. Zeppelins come back, because a vision of the future of aviation always needs to have room for airships. I’ll write that vision up another time.
In some versions of this, the aircrew is still there in the aircraft. In others, the aircrew is in a light industrial park, paying attention to a number of aircraft largely flown by software pilots. There was presumably a period of frightening headlines about robot pilots, but everyone was already so used to self-parking cars and semi-autonomous cargo fliers that it didn’t change the minds of potential passengers.
That’s deeper into the future, though.
In effect, this is a model which uses more or less sustainable inputs (dirty water, clean energy) to create a way to move passengers by air in a more or less recognisable fashion. The energy budget for this could be massive, but if the energy inputs are sufficiently abundant, that’s a matter to build into the pricing model, or the policy support. Today we massively subsidise cheap hydrocarbon-based air travel; in this future we could massively subsidise clean energy and sophisticated grey water systems, with cheap, clean flights as a bonus. That’s a policy question.
I think this is an interesting post, but I think you have artificially constrained the space over which you are optimising. Some passengers will put an enormous premium on an airplane leaving one place at a given time going to a given place. I think fungibility of aircraft size might might be more realistic.