What if the lowest-hanging fruit in aviation decarbonization was not in the air, but waiting right in front of us, on the ground?

This is what David Valaer, founder and CEO of Green Taxi Aerospace thinks.

A pilot since the age of 16, David has spent his whole life surrounded by aircraft, either spending summers a bush pilot in Alaska, flying F-16 fighter jets for the US Air Force or, later on, scaling up and selling a successful helicopter tech company.

A few years ago, David became intrigued by the possibilities that a new generation of electric motors offered to solve one of the issues of everyday commercial aircraft operations: the amount of fuel wasted while taxiing inefficiently through airports.

Did you know that between 5 and 20% of fuel is consumed by airliners while they are on the ground? This happens because most of the time aircraft use their engines to move while on the tarmac, an incredibly wasteful process which in addition to producing unnecessary carbon emissions, also strains aircraft brakes and exposes the engines to foreign object damage.

What if the taxiing could be done with electric motors instead? Green Taxi is working on a system that, David promises, will be able to cut down drastically the amount of fuel aircraft consumer while taxiing. Airlines could be saving in the region of $250-300k per aircraft per year if this technology is finally implemented, not to speak of the related drop in emissions and wear and tear of equipment.

I was also intrigued by this story, so after speaking with David a few times at industry conferences in the last few months, I thought it was best if he could come onto the podcast to share all the details about this promising new technology that his company is developing.

So, tune in for an interesting chat about what Green Taxi can do for the environment and for the bottom line of airlines! (and also for some fascinating details about David’s earlier adventures in aviation!)

What is building a large scale battery-powered aircraft was more feasible than originally thought?

Our guest on this episode of the podcast, Daniel Rosen Jacobson co-founder and co-CEO of Elysian Aircraft, has come on the podcast to explain how asking the right questions and conducting scientific research laid the groundwork for the truly ambitious project that is the E9X electric airliner.

While most electric aircraft projects have focused on the development of smaller aircraft, Elysian Aircraft is taking on the mainstream air travel market with a zero-emissions aircraft concept capable of carrying up to 90 passengers over distances of 1,000 kilometers.

This is certainly a bold proposition, but one that, Daniel explains, is well grounded in science and engineering principles laid out by two papers co-authored by researchers at the Technical University of Delft, in The Netherlands.

What’s more, Elysian Aircraft is backed by Panta Holdings, a company that is no strangers to the world of aviation since it is the owner of Fokker Services Group, which is the remaining part of the iconic Dutch aircraft maker of the same name, now providing a range of MRO and other technical services to aircraft operators.

Elysian’s take on the future of zero emissions aircraft has also attracted the interest of consolidated industry players such as the Air France-KLM group and leasing firm TrueNoord, both of which have signed collaboration agreements with Elysian Aircraft with a view to potentially using the E9X aircraft one day in the future.

This will, for now, have to wait a few years, as Elysian Aircraft refines its concept and builds and tests its first prototypes.

In the meantime, though, we can listen to Elysian Aircraft’s co-founder and co-CEO, Daniel Rosen Jacobson, explaining the key elements of this projected aircraft and the role he expects it to play in the future of commercial aviation!

Is the airship ready for a big comeback? This is not some sort of retro-futurist sci-fi scenario, since there are a handful of companies working to develop a new generation modern-day iteration of this iconic type of aircraft.

But, in fact, airships and, more generally, lighter than air aircraft never fully went away. The US Navy, for example, operated blimps until 1962 (and experimented with them again in the 2000s). Airships have also been used for advertising purposes and, for some time, even Richard Branson’s Virgin Group had an airship division.

Our guests today know all this very well because they experienced it first hand. In fact, I doubt there are many other people in the world right now with the sort of experience and knowledge about how to operate an airship.

Mike Kendrick, Mark Dorey and James Dexter boast decades of combined experience managing airships and they are now the management team of Straighline Aviation, a British startup that aims to become the world’s top airship operator.

If there is a technological advance that has prompted this renewed interest in the airship category, it is the development of the Air Cushion Landing System (ACLS), which enables airships to land, load and unload at pretty much any flat spot that is large enough. This double-chambered airship concept has been under development by Lockheed Martin and, later by, a spin-off company called AT² Aerospace, for about two decades.

As this technology approaches maturity, Straightline Aviation has been also refining its plans to deploy it commercially, with the plan to become the world’s first airship-based air cargo operator.

On today’s episode we assess what are the chances of this happening soon and what are the requirements for a successful commercial air ship operation. We also talk about Mike Kendrick’s earlier ventures in the airship space and how the team is preparing for a nonstop circumnavigation of the globe as soon as the first unit of this novel airship type becomes available.

So, tune in for a fascinating talk about airships and the role they may play in the future of aviation.

Among the top contenders in the eVTOL space, EVE Air Mobility stands out—not because it's closer than others to entering service or because it generates more media headlines.

In fact, what sets EVE aside from the pack is the backing of one of the world’s most successful and technologically advanced aircraft makers, Embraer, which has opted to move slowly but steadily in the field of advanced air mobility.

And leading EVE Air Mobility on the commercial front is our guest in this episode of the podcast, Megha Bhatia, the company’s Chief Commercial Officer.

In this conversation with Megha we cover the latest developments at EVE, including the firm’s participation at the 2025 Paris Air Show, where it showcased a full-scale mock up of its eVTOL aircraft, as well as its commercial traction and future prospects.

We also cover in-depth the 20-year global market outlook report which EVE published earlier this year and discuss what is the role EVE Air Mobility wants to play in the highly competitive advanced air mobility market and its unique selling points.

So, if you are interested in what’s going on in the nascent eVTOL industry and wish to learn more about one of its most promising projects, tune in for this fascinating conversation with Megha Bhatia, Chief Commercial Officer of EVE Air Mobility!

The world badly needs sustainable aviation fuel (SAF) and, fortunately, there is not shortage of entrepreneurs willing to take on the challenge to scale up production. Now, are all SAF pathways the same? Of course not.

Today on the podcast we will talk with Mukund Karanjikar, founder and CEO of CleanJoule, a SAF startup based in Utah that is developing a SAF production method that delivers more joules of energy per unit of fuel mass than other traditional biogenic pathways.

What’s more, not content with powering a commercial aviation industry that is thirsty for SAF, CleanJoule is also developing biogenic SAF for space travel. So, when it comes to CleanJoule, you could well say that the sky is not the limit!

The prospect of clean space travel is quite interesting by itself, but, of course, there are other considerations too, such as cost and strategic independence and, on these two counts, CleanJoule is also ready to deliver, says Mukund.

So, in today’s episode we are going to learn a bit more about CycloSAF and CycloRP, the two flavours of sustainable aviation fuel that CleanJoule is developing (for the aviation and space industries, respectively) and how CleanJoule plans to roll out and scale production before the end of this decade.

We will also talk about the positioning of CleanJoule is the broader and constantly evolving SAF industry landscape and why this startup has got the attention of prominent investors such as Indigo Partners (a private equity firm which owns a global portfolio of low-cost airlines) and Temasek (one of Singapore’s most prominent groups).

So, tune in for a fascinating talk with Mukund Karanjikar of CleanJoule about one of the most promising technologies I have seen so far in the field of SAF!

In this episode of the we welcome Shashank Nigam, who, together with Dirk Singer, has co-authored the Sustainability in the Air book series, two volumes that cover many of the most prominent entrepreneurs, companies and projects striving to make air travel cleaner and more sustainable.

Now, Shashank is no newcomer to the aviation industry. He is also the founder of Simpliflying, a firm that has been providing advice in marketing and sustainability to airlines and airports for quite a few years, and also runs the Sustainability in the Air podcast.

So, in a way, this is a bit of a special episode because you get not just one, but two sustainable aviation podcasters on the show!

With Shashank we talk about the second volume of Sustainability in the Air and what’s new in this new book, which focuses on how the industry is moving from experimentation towards execution and how the different players in the ecosystem are learning to collaborate. Global sentiment towards sustainable aviation has swung a bit with the volatile global political and financial situation, but, as Shashank says, sustainability is a marathon rather than a sprint!

We even had some birds singning in the background during the recording, quite apt for a podcast about sustainable air travel!

In this episode of the podcast we’ll explore one of the most truly disruptive clean-sheet aircraft projects currently underway.

Scott Drennan is President and Chief Operations Officer (COO) of Otto Aviation, a US startup aircraft maker that is developing an ultra-efficient executive jet. The Phantom 3500 uses a teardrop-shaped design to take full advantage of the laminar flow principle and reduce drag to a minimum.

Otto Aviation is, in fact, not a newcomer. The firm has been working on this concept for more than a decade, although in the last few years it has pivoted from the original idea, the Celera 500L propeller aircraft for the general aviation market, to the Phantom 3500, a fully-fledged business jet which aims to compete in the super-mid-size category of business jets.

With Scott we talk about Otto Aviation’s disruptive approach to aircraft design, how laminar flow can be mastered to achieve some unprecedented fuel efficiency gains and what this involves in terms of financial and environmental performance. We also touch upon one of the most eye-catching features of the Phantom 3500: the absence of windows for extra aerodynamical gains and how Otto Aviation is responding with a new way to conceive the passenger experience.

And, following the announcement, made during the 2025 Paris Air Show, that Otto Aviation is investing in a greenfield manufacturing facility in Jacksonville, Florida, we also discuss the company’s investment plans and go-to-market strategy. How many aircraft is it planning to build per year? Who is it planning to primarily compete with and how?

Tune in for a fascinating conversation that combines technical and commercial insights about the unique Phantom 3500 business jet, a flying bullet which may change how we think about aerodynamics and aircraft construction!

When we talk about aviation sustainability, the first thing that usually comes to mind is propulsion technologies or new aircraft designs.

But there are other ways to lower the environmental footprint of flying. Some are even hidden in plain sight!

Today we bring you the story of a company doing its bit to make aviation more sustainable, but in a rather original way: GenPhoenix makes ELeather, which is an innovative lightweight material that can be found on many aircraft seats.

ELeather is actually made by upcycling organic leather scraps, preventing them from going to a landfill (and liberating methane) while, at the same time, helping bring down weight onboard the aircraft, with the related savings in fuel and emissions.

Lisa Conway, Chief Revenue Officer at GenPhoenix, has been on the podcast to share all the details about this interesting technology, which you may have already been using, even without noticing!

Tune in for a fascinating conversation about this segment of the industry that operates at the crossroads between sustainability and passenger experience!

Ivar Aune is the CEO of SiriNor, a company working on an electric jet engine.

Yes, you read that right! While most electric aircraft projects aim to power a propeller, SiriNor is going for the very technology that powers most of today’s commercial aviation industry.

After all, a modern jet engine works by making a turbine spin. But while conventional jets rely on a combustion process that produces very high temperatures, SiriNor aims to replace that bit with an electrically-powered mechanism.

The result: cheaper, easier to build engines which are as performing as conventional ones.

All of this is still some time into the future, since SiriNor is still, by most measures, a young startup. However, Ivar’s team has already tested successfully one of its electric jet engines on the ground and it is aiming to have some certified and commercially-ready models for UAVs and ground-effect-vehicles within the next couple of years.

If this sounds ambitious, you haven’t heard it all yet, because the ultimate goal is to be able to apply the electric jet engine technology to larger aircraft, potentially even the A320/B737-sized airliners that are the workhorses of today’s aviation industry.

A rather tall order, indeed, but Ivar, who spend the earlier part of his career in the Norwegian oil and gas industry, has no doubts about the need for the aviation industry to make bold bets if it is to remain, over the next decades, the engine of growth that it has been to this day.

So tune in for a fascinating conversation about a truly promising, and rather intriguing, technology that has been, pretty much, kept under wraps until very recently!

Wizz Air takes pride in having the lowest carbon footprint per passenger and kilometer in the airline industry, 52g, number that it expects to bring further down as it renews the fleet with larger, denser and more efficient aircraft.

But fleet renewal alone won’t do the trick. In fact, “fleet” is just one of the three “Fs” that the pan-European ultra-low-cost airline relies on to get to Net Zero by 2050, even in a context of growing air traffic.

“Footprint”, that is, efficiency improvements in the way aircraft are operates, is another, relatively minor “F” in this vision. But the bulk of the carbon reduction will rest upon the massive use of sustainable aviation fuel (SAF).

Since production of SAF is currently small, Wizz Air has decided to take a proactive stance and become a direct investor in a number of innovative SAF projects, one of the most promising of which is Firefly, a British startup that turns sewage into SAF.

In this episode of the podcast, Yvonne Moynihan, head of ESG and sustainability at Wizz Air, and James Hygate OBE, founder and CEO of Firefly, share the (virtual) stage to explain this project in detail.

We will talk about how Firefly technology works, how scalable it is and how does this project fit into Wizz Air’s SAF-sourcing ans well as in the airline’s broader decarbonization plans.

Tune in for a fascinating chat about one of the most interesting SAF projects right now in Europe and how it will help Wizz Air strengthen its sustainability credentials even further…