Hello to all the Airliners.net community, this is my first post, I have been an addicted reader of this website for the last three years, and need to thank you all for your interesting discussions and insight.

I have just decided take the big dive because there is that one subject on which I personally dwell which is in my view not often put on the table. Being that my two passions are aviation and sustainable development (we are all full of contradictions aren't we), I have just started working on an academic "mémoire" about "Aviation and climate change" more specifically questioning the ability of the industry to reinvent itself and comply with new societal requirements such as green house gaz reduction targets and shifting to a more carbon neutral activity in the mid to long term. Although I understand that as of today the one and only driver for every player in the industry (Manufacturers, Airlines...) remains financial profitability, I believe we may very well witness a shift in the coming decades (see for instance the recent CORSIA mechanism adopted by the ICAO). Eventhough every evolution is subject to the occasional step backwards (ie. Trump election), there is now in my opinion a strong international consensus that will not grow weaker.
While we can't deny that progress has been made throughout the years in terms of gaz emmissions (or more accurately fuel efficiency), the annual growth of the sector (around 5%) is such that emissions still go up every year : today 2-3% of total GHG emissions come from commercial aviation, that might seem insignificant but actually it is not.
Leaving aside many relevant aspects of the subject (such as ground activities, corporate responsability actions), I am trying to list the main fields of innovation that would enable commercial aviation to evolve :

- Better fuel efficiency : new designs (Blended Wing Body, "intelligent" wing...), more efficient engines (Ultrafan), more efficient aircraft routing (ATC...), better seat occupancy rates
- New propulsion source : bio kerosene, electricity, hydrogen, catapults... (and all the challenges that come with them)

Here are what I think might be the general reasons for a lack of disruptive innovation in commercial aviation sector as opposed to other industries (it mostly concerns manufacturers) :

- Manufacturers and OEM are part of a risk-averse industry, very sensitive to shareholders wishes
- Heavy safety requirements (due to the very nature of flying)
- A capital heavy industry (entry cost in the market are such that it is impossible for a small innovative company to come along)
- A duopoly industry (less need for disruptive innovation when nobody endangers your market position)

Aviation will probably remain fuel dependant for a very long time (propulsion technology using sources with equivalent energy density as good old kerosene are yet to be developed) and fleets renewal takes decades, therefore an A320 produced today may last until 2040. Even as an aviation fan I am having a hard time convincing myself that the present model has a sustainable future and I take comfort in thinking that for certain missions we will always need an airplane. I wonder if the industry is aware of those challenges ahead and what is being done about it.

What are your thoughts about this ? Any potential innovation that would have skipped my mind, any aspect of the subject you would like to discuss ?

Thanks for initiating an important thread, I am also interested in similar issues. Younger I made some academic work (for my minor) related to that, but would like to hear about new development.

Other than some small evolutionary progress mainly driven by fuel economy, I cannot see much disruptive development. The politics and potential pollution fees may boost the development beyond fuel savings, at least I hope so. Politics may even go even too far like obliging biofuels before industry is ready for it or if there are better options to use biofuels elsewhere.

Biofuels and synthetic fuels produced by renewable or nuclear energy may come, though not very soon. Anyone to tell which fuels can be burned in the turbines, as they are, with minor modifications or with a complete redesign of the engine. I understand that turbines are generally much less sensitive to fuels than piston engines, but there may be problems with erosion and corrosion, as well as impurities depending on the source, and in aviation no additional risk of malfunction is tolerated. Most biofuels tend to have lower energy densities than good old kerosene, but there are fuels with higher densities - volume or weight - that might also give more range to critical planes like 321(LR). The high energy density fuels will, however, have problems with storage or safety or something else. Expert insight on this?

A significant point is that the planes emit gases and particles that have positive and negative effects on the radiation balance. You might use the planes for "geoengineering", i.e. countering the greenhouse effect in certain areas, with certain tricks like burning high sulphur fuels high in the atmosphere or tuning the nox content by temperature and fuel/air fraction. The contrails may give a major contribution, both positive and negative, which depends on the position of the sun, i.e. current time and latitude, and also temperature and type of the ground (sea/ice). Routes and timings may thus play a major role. The indirect effects of the contrails were not known very accurately last time I checked. Anyone has more updated info?

Having a truly cleaner and greener aviation would certainly appeal to many customers, as long as it is not just green-washing, as it sometimes has been.

This is also a topic I've long had an interest in, and I'm glad you've summarized most of the salient points about technological limitations. One advantage from an efficiency standpoint is that airlines are highly motivated by financial reasons to get more efficient, even with cheap fuel (fuel is weight that can't be used for payload).

I've had inconclusive arguments with people about whether the increase in efficiency is actually a net evil because of induced demand (it gets cheaper, so more people do it), I'm sure some economists have an opinion.

On the biofuels front, I've been reading quite a bit, here's my next read: http://commons.erau.edu/mcnair/vol1/iss1/4/ . From what I've seen thus far, challenges with biofuels are gelling at low temperature, as well as residual organic matter that can gum up over time. One promising idea is fast pyrolysis (https://en.wikipedia.org/wiki/Pyrolysis_oil) of agricultural waste into pyrolysis oil, which then gets deoxygenated and refined into kerosene. Meanwhile, the leftover charcoal can be used as a soil supplement and carbon sink (the porosity helps trap water and fertilizers in the topsoil for longer (https://en.wikipedia.org/wiki/Biochar). I'm presently trying to assess how the economics of this would work out, as I want to see aviation become greener in the future.

To the point about using highly sulfured fuels for geoengineering, I'd recommend reading this article: http://www.intellectualventureslab.com/ ... shield-faq . The authors state that using high-sulfur fuels in planes would be ineffective because a) the altitude is too low and b) it would reduce efficiency. On polar flights (west coast US to EU/Asia), I think you might be able to get into the lower stratosphere to where it may help, and I'm not sure how much efficiency loss you'd get from having sulfur in there, but I can't imagine it'd be more than a fraction of a percent. With the right incentive, that could be overcome. What I think the bigger potential showstopper is with this idea is turbine blade sulfidation, where the sulfur oxides corrode the turbine blades, embrittle them, and cause increased wear and premature failure. Because turbine blades aren't cheap, I could see this being a big issue. I've read that coatings have been developed to make this less of an issue, but I'm not sure how well they work. Where's Lightsaber? I'm sure he knows more.

Yet another possible issue with the sulfur is local air quality concerns near airports. One of the main drivers for low-sulfur jet fuel (more expensive to remove sulfur) is the fact that people don't want the sulfur oxides in the lower atmosphere for health reasons. SO2 is a bit like ozone, it's great to have it up there, but not down here. A possible workaround would be to have your CWT full of low-sulfur for T/O, and then wing tanks with high-sulfur, and outboard with low-sulfur again for approach. Either way, it introduces complexities that many airlines wouldn't want to deal with. Maybe on that front, building the Stratoshield is the better idea.

After watching this documentary I'm not convinced about global warming from CO2:

https://www.youtube.com/watch?v=D-m09lKtYT4

YIMBY wrote:

Biofuels and synthetic fuels produced by renewable or nuclear energy may come, though not very soon. Anyone to tell which fuels can be burned in the turbines, as they are, with minor modifications or with a complete redesign of the engine. I understand that turbines are generally much less sensitive to fuels than piston engines, but there may be problems with erosion and corrosion, as well as impurities depending on the source, and in aviation no additional risk of malfunction is tolerated. Most biofuels tend to have lower energy densities than good old kerosene, but there are fuels with higher densities - volume or weight - that might also give more range to critical planes like 321(LR). The high energy density fuels will, however, have problems with storage or safety or something else. Expert insight on this?

Biofuels are indeed a very active field of research : In 2014 Air France (in partnership with Safran and Airbus) had been experimenting on a weekly flight TLS-ORY, they were using a 10% cane sugar based kerosene mix, using the same airplane and monitoring the effects on the engines. At the end of the test period, Safran expertise revealed that "the effects of the two types of fuels [classic and the mix] was indistinguishable", source here (in french only I am afraid). I think a lot of other Airlines have been experimenting on this as well and Airbus is not staying idle about it (they have their own algae cultivation center in Germany), they are also stating on their website that "50/50 blend sustainable aviation fuels already are certified for commercial flights".

There has been some controversy about biofuels : depending on the generation and the process used, life-cycle analysis of some biofuels (palm or soy based for instance) show they have a worst carbon footprint than regular fuels when all the steps from production to burning are taken into account. But then again this is being tackled by second and third gen biofuels (as highlighted LH707330 link).

More broadly is biofuel the only realistic mid-term alternate solution (circa 2030) ? Electrically powered aircraft are dependant on storage technology enhancement (Lithium Battery has led us as far as the E-Fan). Hydrogen powered HY4 still has the look of a glider... What about BWB, lighter frames ?

It will also come down to what government incentive is given (research funding), what international/national regulation is enforced and how.

I knew this thread would trigger climato skepticism, that came quite quickly though. Anyway according to an Airbus study on 10 000 people : 96% believe aircraft will need to be more sustainable or ‘eco-efficient’ : http://www.airbus.com/innovation/future-by-airbus/

The climate has been changing for 4.5 billion years and there is nothing you can do to stop it. Humans have only been around for two hundred thousand years. Go ahead, use all of the biofuels you want, the Earth will still finish coming out of the last ice age.

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

LH707330 wrote:

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

Almost all scientists reject man-made climate change.

Would you mind not hijacking this thread as there is no chance this can evolve into a healthy and sound debate ?

Yersterday saw another news on the biofuel front :

An ATR 72-600 of the Swedish carrier BRA (former Braathens Regional) took off from Stockholm-Bromma today to Umeå fueled at 45% with fossil-free used cooking oil, marking the first biofuel-powered flight of an ATR aircraft.

I guess will start to see more and more of those.

blacksoviet wrote:

LH707330 wrote:

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

Almost all scientists reject man-made climate change.

I created a new thread for that discussion: viewtopic.php?f=11&t=1354737

Cool story about the ATR. As we move forward, I think we'll see more decentralized uses of biofuels as opportunities present themselves. One project that I've been following in the PNW has been the one at WSU using woodchips: https://cleantech.wsu.edu/home-page/ren ... oproducts/

blacksoviet wrote:

LH707330 wrote:

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

Almost all scientists reject man-made climate change.

Thanks for that tidbit of alternative facts, blacksoviet. You've got it all backwards.

Anyway, the solar energy and electric car revolution is in motion. It will even happen sooner than expected, and that's fantastic.

Putting coal on the shelf for power-production, and dropping diesel, gasoline and oil for car, train, ships and industry, means that the one mode of transportatuon where there is no immediate alternative to be seen: aviation, likely will continue using fossil. And that is really not a problem. Aviation alone doesn't make global warming happen.

blacksoviet wrote:

LH707330 wrote:

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

Almost all scientists reject man-made climate change.

The overwhelming majority of climate scientists believe the evidence points to man-made climate change. The proportion is almost 100%.

If you have an objective source that has different information, I'd love to see it. In fact, I'd love for this all to be a hoax.

BobleBrave wrote:

Although I don't fundamentally disagree with your opinion, there are a few points which are a bit stereotypical and could be addressed more subtly in your memoire

BobleBrave wrote:

aviation and sustainable development (we are all full of contradictions aren't we)

Why would it be a contradiction ? Transporting people around the world is part of human development, as people will carry their ideas, knowledge, experiences and cultures with them. I sincerely believe that enabling many people beyond the top elites to travel to distant locations helps strengthen human ties and understanding, and directly reduces contributes to reducing the urge of waging costly wars. Even though we obviously do have a long way to go still...
Long range travel is a strong enabler for science and technical progress as well.

Besides, once you look at the full lifecycle of transport means, including infrastructure and vehicle utilisation, aviation is actually not that bad, especially beyond 1000km. Not perfect for sure, but not that bad compared to other means of transport.

BobleBrave wrote:

the one and only driver for every player in the industry (Manufacturers, Airlines...) remains financial profitability

That is somewhat unfair. Safety is also a major driver for the industry, often at the expense of short-term financial performance. Lots of money is spent in technical investigations (and in the operating costs of the agencies behind those investigations), lots of money is spent on technical upgrades to correct identified issues, lots of money is spent on safety management systems, etc...
Also, up till a few years ago, OEMs were sinking billions upon billions is new developments, with such programs following one another. Airbus for example had a new dev program and/or a major mod program going on continuously from teh early 80s till now. Returns to shareholders are therefore not that big.
Same with airlines, it is only recently (after about 80 years) that airlines have really begun generating sustained profits.

While not as visible, I do think that "green" aspects have been taken into account also, with management of hazmats, reducing the environmental footprint of aircraft construction...And although mainly driven by fuel costs, the fuel consumption and combustion efficiencies of aircraft have greatly incresed over the past few decades.

BobleBrave wrote:

today 2-3% of total GHG emissions come from commercial aviation, that might seem insignificant but actually it is not.

In absolute terms, it does indeed represent quite a few tons of gases pumped into the atmosphere. So reducing the emissions is always welcome.
Then again, it means that any improvement in aviation emissions, even a revolutionary one, will only have marginal effects on the overall GHG budget.

BobleBrave wrote:

- Manufacturers and OEM are part of a risk-averse industry, very sensitive to shareholders wishes

Yes and no. Since a few years the OEMs want to secure their financial positions, and have publically declared their aversion to major new aircraft development programs. However small continuous improvement efforts to existing products are running, and could be increased. Something similar to the auto industry where a same car type evolves and ends up completely changed after 10-15 years. The problem here is that the designers have to take into account a number of old design decisions which are not always well documented, or were taken based on the experience of a long-since retired engineer. Rules & regulations & internal requirements also stack up over the years. So in practice, any significant upgrade to existing products is difficult and slow. It will eventually accelerate, but only after some significant "house cleaning" of regulations, internal requirements, and design methods & tools. But that has little to do with shareholders

BobleBrave wrote:

- Heavy safety requirements (due to the very nature of flying)
- A capital heavy industry (entry cost in the market are such that it is impossible for a small innovative company to come along)
- A duopoly industry (less need for disruptive innovation when nobody endangers your market position)

Definitely. But you miss the most important issue : aircraft design and manufacturing is carried out by tens of thousands of people, even for a single given product. The inertia of such an orgranistion is huge. To make things worse it calls upon very deep technical knowledge, carried by dedicated teams and experts in the organisations. These people will have a natural tendency to reproduce what they have always done.
To put it simply : if you employ a chocolate expert, a flour expert, a pecan nut expert and a baking oven expert to produce chocolate brownies, then when you ask them to create a new dessert, it is highly unlikely they will come up with a strawberry tart. They'll probably propose some kind of chocolate cake variant. And the improvement over the existing brownies will not be very big
Thus technical improvement is mainly blocked by sociological factors, not economic ones.

BobleBrave wrote:

I am having a hard time convincing myself that the present model has a sustainable future

That may be a bit dramatic. Overall the environmental footprint as stable at worst, which is not a given with the steep increase in demand. Some parts of the model are not sustainable, like sending small aircraft every few minutes on a same route. But I wouldn't throw the baby away with the bath. The industry needs to continue to improve, and even improve more, but we shouldn't be unrealistic.
I also think that while the big airliner business is a bit closed, it may still be disrupted from e.g. the emergent urban mobility ideas, which will need radically new technologies. We'll see !

airmagnac wrote:

Very interesting contribution, that's a lot to discuss.

airmagnac wrote:

BobleBrave wrote:

aviation and sustainable development (we are all full of contradictions aren't we)

Why would it be a contradiction ? Transporting people around the world is part of human development, as people will carry their ideas, knowledge, experiences and cultures with them. I sincerely believe that enabling many people beyond the top elites to travel to distant locations helps strengthen human ties and understanding, and directly reduces contributes to reducing the urge of waging costly wars. Even though we obviously do have a long way to go still...
Long range travel is a strong enabler for science and technical progress as well.

In a way you're right, I don't question the great impact that commercial aviation have had in building bridges between cultures and people, though I believe today's great science enhancer and enabler is the internet (and new information and communication technologies in general), sharing knowledge has indeed become as easy as a click on a laptop. Whether it shall completely replace face-to-face interaction or transform travelling needs is an entire debate of its own.

airmagnac wrote:

Safety is also a major driver for the industry, often at the expense of short-term financial performance.

Agreed

airmagnac wrote:

Also, up till a few years ago, OEMs were sinking billions upon billions is new developments, with such programs following one another. Airbus for example had a new dev program and/or a major mod program going on continuously from teh early 80s till now. Returns to shareholders are therefore not that big.
Same with airlines, it is only recently (after about 80 years) that airlines have really begun generating sustained profits.

That's interesting, I hadn't thought about the historical evolution of the importance of profitability/revenue and shareholder's influence (what you say makes a lot of sense), but wouldn't you agree that nowadays, it is clearly shaping every investment decisions (for both OEM and Airlines)?

airmagnac wrote:

BobleBrave wrote:

today 2-3% of total GHG emissions come from commercial aviation, that might seem insignificant but actually it is not.

In absolute terms, it does indeed represent quite a few tons of gases pumped into the atmosphere. So reducing the emissions is always welcome.
Then again, it means that any improvement in aviation emissions, even a revolutionary one, will only have marginal effects on the overall GHG budget.

It may be marginal today but given the growth of the sector and the efforts made by other industries (e.g. electricity production, car industry...), the relative share of commercial aviation in the GHG burden might increase faster than we expect. It will again come down to the political choice of who makes the effort and who pays for the consequences (today kerosene as opposed to other fuels remains not taxed).

airmagnac wrote:

BobleBrave wrote:

- Heavy safety requirements (due to the very nature of flying)
- A capital heavy industry (entry cost in the market are such that it is impossible for a small innovative company to come along)
- A duopoly industry (less need for disruptive innovation when nobody endangers your market position)

Definitely. But you miss the most important issue : aircraft design and manufacturing is carried out by tens of thousands of people, even for a single given product. The inertia of such an orgranistion is huge. To make things worse it calls upon very deep technical knowledge, carried by dedicated teams and experts in the organisations. These people will have a natural tendency to reproduce what they have always done.
To put it simply : if you employ a chocolate expert, a flour expert, a pecan nut expert and a baking oven expert to produce chocolate brownies, then when you ask them to create a new dessert, it is highly unlikely they will come up with a strawberry tart. They'll probably propose some kind of chocolate cake variant. And the improvement over the existing brownies will not be very big
Thus technical improvement is mainly blocked by sociological factors, not economic ones.

Indeed, the industry faces a "path dependence" dilemma whereby every single aspect of the current socio-technical regime has been shaped around fossil fuel jet-engine/props aircrafts, everything, from government policy to engineering culture, infrastructures, user preference, R&D is therefore dynamically stable. There is that quote which sums it up perfectly : "A technology is not chosen because it is the best one, it is the best one because it has been chosen".
But today, an exogenous pressure is put on that stable system (a need for climate change mitigation and GHG emission reduction) which might open up windows of opportunity to develop new technology (coming from various niche of innovations) and help them break through mainstream markets.


That is why I find the period ahead so interesting for the industry.

Regards.

blacksoviet wrote:

LH707330 wrote:

Ok, for the sake of this thread, let's assume that the objective is to reduce use of fossil fuels in aviation. If you don't agree with 97% of scientists that anthropogenic climate change is real, please start an OT thread about that.

Almost all scientists reject man-made climate change.

<deflated>

We've released about 420 billion metric tonnes of fossil carbon back into the environment.
Sequestering that mass took about 500 million years.
Not surprising that atmospheric CO2 has increased by 100+ppm and thus overshot the ranges
that we associate with our current climate.

IMU you haven't seen real man made climate change yet.
But watch out for what is to come.
Expect a train wreck.

BobleBrave wrote:

There has been some controversy about biofuels : depending on the generation and the process used, life-cycle analysis of some biofuels (palm or soy based for instance) show they have a worst carbon footprint than regular fuels when all the steps from production to burning are taken into account. But then again this is being tackled by second and third gen biofuels (as highlighted LH707330 link).

If you mean corn ethanol, then you are correct. However, no serious biofuels advocate would recommend corn ethanol for that very reason.

Aviation fuels (pun intended) much of the world economy while not using all that much of the world's fossil fuel. Cars, space heating, and to a lesser extent semis can and are going electric. Let the world hasten this electrification, and aviation simply continue to improve fuel efficiency. Use fossil fuels where they really are needed and not where they can be replaced.

Volts, Bolts, Priuses, Teslas and all the models in China will likely start making a significant dent in fossil fuel consumption within 5 years.

VOX had an excellent article on this last week. Previous projections in the pace of transportation electrification are hopelessly outdated. We are about 5 years ahead of what earlier projections were.

BobleBrave wrote:

wouldn't you agree that nowadays, [profitability/revenue and shareholder's influence] is clearly shaping every investment decisions (for both OEM and Airlines)?

I would not be so black and white.
In a way, that's how it should be. If in the long term there is no profit generated in the system, then it is not sustainable.
And postive business cases were always somehow required. It's just that before, the industry was maturing, there were always lots of things to discover, and every new technological solution paid off. There was no need to waste time thinking about value and costs.
The issue now is that aircraft are such integrated complex systems that any modification will have expensive side-effects. Therefore business cases are invariably in a grey area (or whatever color grey + red makes), where added value is roughly similar to total costs, and it must be rigorously assessed as early as possible. The trouble is that the engineering organisations first have to figure out how to perform such assessments. Without going into details, let's just say that it is not as easy as it seems.
I would agree that there is a lot of petty cost cutting, but generally in support functions. From what I have seen, lots of money is spent in aircraft development ideas, and more could be spent if opportune. So again I wouldn't be so harsh on the financial/shareholder aspects.

BobleBrave wrote:

It may be marginal today but given the growth of the sector and the efforts made by other industries (e.g. electricity production, car industry...), the relative share of commercial aviation in the GHG burden might increase faster than we expect.

Indeed, which is why I mentioned the absolute figures of gas volumes released. I think it would give better targets instead of relative figures, which are dynamic by nature. And which is why I agree that the air transport industry has to be active on the topic. But aviation emission reductions will not help us much if cars, meat, utility power etc...don't significantly change first.

BobleBrave wrote:

the industry faces a "path dependence"

Excellent, this is indeed the right term.
However the path dependence is not on fossil fuel itself ; that is a physical dependence due to the high specifc energy (by weight and volume) of fossil fuels combined with the physical property that the energy in these fuels is easy to liberate (from an pure energy point of view, it would be much better to fly on cookies) and the general simplicty of extraction & distribution.
The path dependence is on the tube-with-wings-with-engines-under-the-wings-with-APU-in-the-back-.... solution. This is so engrained into airport design, maintenance GSE infrastructure, certification rules, initial design architectures.... that there is no way to make anything significantly new anytime soon. The problem is that we have squeezed this basic design of most of its efficency potential, so we'll need to jump to new solutions if we want to improve.
Take the BWB for example. If the design organisation is split in a wings design team and a fuselage design team, then any thought of BWB is dead on arrival. Because the organisation would rather preserve itself in its present form rather than adapt to the new product breakdown, which in this case implies merging fuselage and wing design. And that's before even adressing any of the major technical issues of a BWB design.

BobleBrave wrote:

an exogenous pressure is put on that stable system

As mentioned, there is already internal pressure, so your exogenous pressure is not pressing on a void. And it is not that great, given that aviation emissions alone cannot change significantly the global picture for now, and that there are others areas (cars, power generation & distribution grids) where improvements can be made much quicker. So don't expect any dramatic breakthroughs anytime soon.

Good topic thread starter.
Of course (with aircraft particularly) energy density is critical.So hard to see a way round hydrocarbon fuels.I guess one could split the problem into two areas.
1.General CO2/Global warming.
2.Damage (by a range of exhaust chemicals) to humans living near airports.

With the former one perhaps should discuss the use of bunker fuel powered oil burning super tankers before worrying about ever more fuel efficient aircraft.

But No 2.I personally like the idea of aircraft manoeuvring around airports using electric wheel motors.That should cut down a load of local pollution.It would be nice to see more work on steeper approaches to runways (5%?).This would cut down local pollution and nouse pollution.

Wish there was something one could do about T/o but I doubt they can.

airmagnac wrote:

So don't expect any dramatic breakthroughs anytime soon.

I think a lot of it will depend on the long term price of oil.

As established, aviation is dependent on high energy density, stable, liquid fuels for the foreseeable future, whereas other modes of transport aren't.

In the idealistic vision of a World where every other mode of transport has moved on from oil distillates, whatever available resources are left would be sufficient to keep the world airliner fleet flying for ages. It would all depend on how the industry re-settles around much lower production volumes and what would consequently happen to prices. In that case, however, volatility (of the price, not the fuel ), which is the absolute nightmare of any airline, would decrease (no reserve worries, speculators not really interested anymore), while the worries about the environmental impact basically disappears since global consumption has dwindled.

This is an extreme case, of course, but at the end of the day biofuels still mostly compete with food crops and while it is quite doable to fly a few experimental flights with bio-blends, increasing production of crop-based fuels to even a fraction of fossil jet-fuel volumes would create a completely different market dynamic which might or might not result in viable prices vs. oil and might hurt the environment more than it helps it as the increased demand for arable land will put even more pressure on the World's forests.

A perfect example is the BRA ATR-72 flight which used a blend of bio-fuel based on used cooking oil.
Cooking oil has virtually no value as it stands today, but if we put any serious effort in using used cooking oil to create fuel, we'd find out quickly that we'd create a market in which used cooking oil would suddenly become a valued commodity (hence not free anymore), and in any case, demand would outstrip production very quickly... Used cooking oil is a fun idea, but a non-starter when it comes to scaling it into industrial scale.

Any serious attempt at a widely available, renewable, carbon-neutral (or almost) hydrocarbon fuel would come from algae/bacteria production in my opinion. I don't think the technology that could provide us with the required volumes at competitive prices compared to crude oil is quite there yet... But here's to hoping!
Interestingly, 'manufacturing' our own fuel could have the benefit of making the end result less prone to price speculation. Airlines would be happy to pay a little more for a fuel of which the price is not completely unpredictable.

I also think that mag-lev railroads will one day replace many of the long-haul air routes we have today. This will reduce the need for jet fuel.

BobleBrave wrote:

Indeed, the industry faces a "path dependence" dilemma whereby every single aspect of the current socio-technical regime has been shaped around fossil fuel jet-engine/props aircrafts, everything, from government policy to engineering culture, infrastructures, user preference, R&D is therefore dynamically stable. There is that quote which sums it up perfectly : "A technology is not chosen because it is the best one, it is the best one because it has been chosen".
But today, an exogenous pressure is put on that stable system (a need for climate change mitigation and GHG emission reduction) which might open up windows of opportunity to develop new technology (coming from various niche of innovations) and help them break through mainstream markets.

This path dependence point is a good one, it creates a chicken and egg situation that's unlikely to get resolved anytime soon. With cars, it's easier to be a disruptor like Elon Musk, but in aviation, a lot more would have to change at the same time. Looking at aviation, I can't see too many major paradigm shifts like BWB taking off soon, for reasons we've seen discussed here before.

parapente wrote:

Good topic thread starter.
Of course (with aircraft particularly) energy density is critical.So hard to see a way round hydrocarbon fuels.I guess one could split the problem into two areas.
1.General CO2/Global warming.
2.Damage (by a range of exhaust chemicals) to humans living near airports.

With the former one perhaps should discuss the use of bunker fuel powered oil burning super tankers before worrying about ever more fuel efficient aircraft.

But No 2.I personally like the idea of aircraft manoeuvring around airports using electric wheel motors.That should cut down a load of local pollution.It would be nice to see more work on steeper approaches to runways (5%?).This would cut down local pollution and nouse pollution.

Wish there was something one could do about T/o but I doubt they can.

With general CO2, I think fuels made from cellulosic waste will eventually catch on when the business case can be made, perhaps accelerated by pigouvian taxation. That's the only major breakthrough I can see happening there.

Regarding your second point, there are a few ideas that I've batted around, but they all have their problems:

1. The jet donkey, that we discussed inconclusively a few years back (might be time for a thread bump): viewtopic.php?t=770535
2. Water injection: using water as a charge-air coolant and a turbine coolant in the right amounts and places can actually lower NOx levels as well as increase thrust:
https://ntrs.nasa.gov/archive/nasa/casi ... 015629.pdf
https://powergen.gepower.com/services/u ... ction.html

Admittedly, water injection doesn't do much for the taxi phase, but as far as local pollutants like soot, modern engines are fairly clean, and they only produce the NOx when they warm up at takeoff thrust.

I'd be interested to know if some research has been done into fuel additives to promote or suppress contrail formation at the right times. I know USAF looked into it for the B-2 (for lower visibility), but they used some pretty nasty chemicals and it didn't work very well. I've read that some research goes back and forth on the net radiation effects of contrails, perhaps someone will find a fuel additive that's a net benefit.

blacksoviet wrote:

I also think that mag-lev railroads will one day replace many of the long-haul air routes we have today. This will reduce the need for jet fuel.

Not in fly over country and its fringes. They don't do infrastructure investment anymore.

https://www.flightglobal.com/news/artic ... ng-421500/

This was the system/systems I was thinking about with reference to cutting emissions on the ground.There are various articles and ideas about this.They seem to suggest that it is a no brainier in terms of economics yet no one has done it yet to my knowledge.
The beauty of this system is it requires no infrastructure development/changes.
Now of course if they have 'really' discovered metallic hydrogen (see recent science articles) that that (to quote S Jobs) changes everything.
One assumes liquid hydrogen is just too dangerous.

parapente wrote:

I personally like the idea of aircraft manoeuvring around airports using electric wheel motors

Good news for you, it seems that the taxibot finally made it to certification on the 737NG and A320. Hopefully the widebody version will follow soon
http://www.taxibot-international.com/
And I believe it is an electric design.
It's a first step with limitations of course, but going in the right direction

Real autonomous eTaxi is a tougher nut to crack as the motor assemblies have to be added on the gears which are a sfety critical item (they support the aircraft after all) and work in a disgusting environment (hot, cold, dust, mud, water...). So those assemblies will be expensive. Add the cost of the associated power electronics and the integration of all this into the aircraft and the system will be expensive to buy, no matter what. As the system adds weight, the fuel consumption in flight will be higher, so that the net fuel gain is fairly low. So there is a delicate balance to find between the actual value of the system and its costs. Actually, this is a proposition which could really benefit from some kind of pricing of carbon emissions, whether a tax or another mechanism.
Regardless, I'm hopeful that we will see it some time soon. Some tweaking of the design solutions and the business models might enable it.
[note : WheelTug is not an eTaxi. It's an autonomous tug for pushback only. It's way too underpowered to propell an aircraft at taxiing speeds. This is why the website insists on time savings during pushback and not on fuel savings. All based on some rather "interesting" assumptions and logic ]

The other dimension of airport footprint reduction is to upgrade all the vehicles, local power generation, heating of buildings etc... to "cleaner" technologies. I believe that is actually on-going, albeit slowly and discreetly.

Francoflier wrote:

I think a lot of it will depend on the long term price of oil.

For sure it is the number one driving force for change, but fuel prices above 110$ haven't resulted in radical new designs in the 20010-2015 period. Not even an all new design.
The decision-making in that time-frame was certainly the result of more factors than just fuel prices, but I take from it that we would need to see a sustained price above 130$ to trigger on its own a major change in design thinking. I guess that's unlikely, but then again, we've been seeing very unexpected things these past few months....

As mentioned, green political decision are unlikely to sufficently pressure the industry into doing anything new. The last potential driver for change is competition, but the current non-Aor B aircraft designers are short on cash and/or have a long way to go before offering a competitive plane. And anyway, everyone is doing tubes-with-wings.
Hyperloop may be able to offer some competition, but honestly I'm waiting to see the safety studies and resulting constraints on the design, before I make my mind up on the viability. So far, nothing really new has been put on the table ; Maglevs have been demonstrated for 30 years, and vacuum tubes for longer than that. I have not seen much in terms of managing the combination of high speed/high energy levels and vacuum, and the resulting safety and operational constraints.

parapente wrote:

Now of course if they have 'really' discovered metallic hydrogen (see recent science articles) that that (to quote S Jobs) changes everything.
One assumes liquid hydrogen is just too dangerous.

metallic hydrogen has long been predicted. it is stable under > 5million bar pressure below ~5°K.

Very adventurous to think that this would be less dangerous than cryogenic liquid hydrogen.

Thanks for the link on Taxibot.I had not heard about it.Looks like a superb solution.Of course there is the cost of the vehicles themselves (one would need quite a few I imagine).But I think they should be insisted on Frankly.Easyjet states that they use 4% of fuel on ground handling opp's which must add up to shed load of £££ so it would clearly be worth paying for I would have thought.Bring it on! (Starting with Heathrow!)

airmagnac wrote:

As mentioned, green political decision are unlikely to sufficently pressure the industry into doing anything new. The last potential driver for change is competition, but the current non-Aor B aircraft designers are short on cash and/or have a long way to go before offering a competitive plane. And anyway, everyone is doing tubes-with-wings.
Hyperloop may be able to offer some competition, but honestly I'm waiting to see the safety studies and resulting constraints on the design, before I make my mind up on the viability. So far, nothing really new has been put on the table ; Maglevs have been demonstrated for 30 years, and vacuum tubes for longer than that. I have not seen much in terms of managing the combination of high speed/high energy levels and vacuum, and the resulting safety and operational constraints.

Indeed if the rules of the market stay unchanged, fuel prices are likely to remain the only external driver for a more carbon neutral aviation. That being said I think we might have already witnessed a first (important) step from the international community (namely the ICAO) towards the implementation of a pigouvian tax. The Carbon Offsetting and Reduction Scheme for International Aviation adopted last year represents a great opportunity :

the average level of CO2 emissions from international aviation covered by the scheme between 2019 and 2020 represents the basis for carbon neutral growth from 2020, against which emissions in future years are compared. In any year from 2021 when international aviation CO2 emissions covered by the scheme exceed the average baseline emissions of 2019 and 2020, this difference represents the sector's offsetting requirements for that year.

Pilot phase and first phase (from 2021 through 2026) will apply to the volunteering States (among which China, UK, US, France, UAE, Ireland, Germany and many others) and from 2027 onward, to all States that have an individual share of international aviation activities in RTKs in year 2018 above 0.5 per cent (with a few exceptions).

Regarding the Hyperloop I see it as a potential substitute for aviation in the long run (for a few city pairs), but the infrastructure required means secondary markets and transoceanic routes will not be served any time soon. By the way, ironically enough, it has recently been decided Hyperloop's HQ in Europe will be located in Toulouse.

parapente wrote:

Wish there was something one could do about T/o but I doubt they can

Isn't there a possibility to use electrically powered catapults ? I think there was a thread about it a while ago, I know it is a far fetched idea but wouldn't that solve the issue ? Take-off is the most energy consuming phase of flight, on top of that : less max power needed means less weight hence less fuel burn (but go-arounds could become a problem with less powerful engines). I know there are quite a number of issues mostly regarding the stress on the plane's structure, but contrary to aircraft carrier catapults, at an airport the available runway length translates into lower acceleration requirement.
As for the landing, there must be a way that all this kinetic energy doesn't go to waste!
I know those are unrealistic in the mid-term for quite a number of reasons (who is going to invest for such techs? Airports? States?) but then every revolution starts as an unrealistic-almost-dangerous dreams.

parapente wrote:

Thanks for the link on Taxibot.I had not heard about it.Looks like a superb solution.Of course there is the cost of the vehicles themselves (one would need quite a few I imagine).But I think they should be insisted on Frankly.Easyjet states that they use 4% of fuel on ground handling opp's which must add up to shed load of £££ so it would clearly be worth paying for I would have thought.Bring it on! (Starting with Heathrow!)

TS is involved with another similar system, claimed to use 1/6 the fuel of a regular taxi (imagine the fuel use is due to needing to run the APU to power it)

Worldwide, taxi fuel was estimated at $7B for 2012....

https://www.thestar.com/business/2017/0 ... sions.html

BobleBrave wrote:

Regarding the Hyperloop I see it as a potential substitute for aviation in the long run (for a few city pairs), but the infrastructure required means secondary markets and transoceanic routes will not be served any time soon.

Hyperloop has some serious safety problems that I have not seen addressed yet in an appropriate way. Certifying it for passenger traffic may be harder than an airliner, depending on the legislation of the site.

Train or train-like terrestrial transport systems will certainly substitute avions in short distances in many parts of the world, where building the infrastructure is feasible, also in the US if they overcome the political barriers, but will have harder times for longer distances. I do not believe that a few hours flights will be challenged by any ground transport in the future, unless there are political obstructions for flying, including security issues.

BobleBrave wrote:

Isn't there a possibility to use electrically powered catapults ? I think there was a thread about it a while ago, I know it is a far fetched idea but wouldn't that solve the issue ? Take-off is the most energy consuming phase of flight, on top of that : less max power needed means less weight hence less fuel burn (but go-arounds could become a problem with less powerful engines). I know there are quite a number of issues mostly regarding the stress on the plane's structure, but contrary to aircraft carrier catapults, at an airport the available runway length translates into lower acceleration requirement.

If you use some kind of catapult or pusher on the landing gear, the stress will be not that much more than in the braking, and much less than in runway excursion, just opposite direction. It is not impossible to handle, though it will require some redesign and testing. In any case the engines must be set close to full power before take-off. I find the idea interesting, though I admit that it requires major redesign of the airport infrastructure, whose feasibility I refrain to estimate. All failure modes have to be studied, which may pose the true challenge.

One reason why hydrocarbon fuels are optimal for airliners is that for the power to be generated, they hold more energy per unit volume than any other fuel, including hydrogen (hydrogen holds more per unit MASS). Nuclear propulsion is technically feasible, but not realistic given the very real implications of a crash.

However, it is possible to use electricity to turn CO2 back into hydrocarbons and make jet fuel from the product. If we can master a truly clean and renewable power source like fusion, we could continue to fuel airplanes with these mixtures. This doesn't solve the other emissions issues (NOx) with airplanes, but NOx is a much smaller issue than CO2. NOx spontaneously degrades back into oxygen and nitrogen over a half life of hours to days.

It seems there is a general consensus on the need for hydrocarbon fuels in aviation, I was wondering about the state of advancement of various innovations and how close to mainstream market diffusion they currently are? Regarding fuel efficiency, propfan was thought to represent the next bold step within a reasonable time frame.

For example where is Safran project at ? It has had very few public news in the last two years (since the 1/5 scale model tunnel testing in 2015). Are we getting closer to seeing those mounted on a tesbed airframe?

While developing the engine is a major step itself, we will have to see cooperation from A or B to see it happen one day. Due to its dimension, such a technology would require a cleansheet airframe allowing it to be rear-mounted for example.




Does anyone have informations about it? Any other program from other manufacturers?

Just as a watcher, my general sense is that fuel efficiency is already very, very good. An A321 NEO with high density seating is just fantastic, well over 100 MPG per passenger. And it goes 550 mph.

Aviation has already received a lot of elegant engineering upgrades. It is one of humanity's most efficient, mature logistical and engineering processes. In part due to the oil price spike of 2007-08. That harshly motivated Boeing and Airbus (and engine manufacturers) to do their best. And they did. The solutions are great. You don't need to look much farther than the Boeing 787-9/10 and Airbus A359/X. That is the best humans can do right now. I have no means to critique that work. Immense armies of genius engineers did those.

I think hydrocarbon-based aviation is quite sustainable. Other parts of the economy will adjust. This is the highest-value use of the internal combustion engine. All other uses will stop before this one does. Or, maybe I am wrong and solar powered heavy gliders will dominate in 30 years. I don't think so though. Things will stay relatively as-is for 30+ years, even if oil reaches 100-200 dollars per barrel equivalent, as it has in the past. People will still fly.

The carbon intensivity of economies is falling over time. It will fall to low, sustainable levels eventually. And we will figure out how to mitigate carbon releases fully, using scrubbers or something like that. Through it all, aviation will look like it does now, maybe with slight changes to the fuel.

Just a note regarding trains. I don't know the exact figures, but to electrify them required a whole lot of traffic to justify the cost. At to get that traffic trains would have to be more flexible in taking on freight, they would have to go a lot faster (also incredibly more expensive to build and maintain), and automatic train control (in the works, but hopelessly late). The other side of this is that when those things are in order trains are incredibly efficient at hauling freight and equally superior in comfort for passengers.

Sea rise of 6 feet will spell disaster for any number of lines, and literally no one has plans for where those tracks can be moved. Those of us, now adults, are leaving this problem to great grand kids.

As far as I can see the only real issue for the airline industry burning hydrocarbons at high altitude is ..cloud formation.The level of high altitude cloud formation does (I believe) have a strong effect of global temperatures.
Mind you I can't see what can be done about it but it might be a real issue that can be directly focused on this industry alone.

parapente wrote:

As far as I can see the only real issue for the airline industry burning hydrocarbons at high altitude is ..cloud formation.The level of high altitude cloud formation does (I believe) have a strong effect of global temperatures.
Mind you I can't see what can be done about it but it might be a real issue that can be directly focused on this industry alone.

I agree, although to my knowledge there is not yet a true consensus about its overall impact within the scientific community (and it represents one of the major debate between NGOs and the industry). Models need to take into account a lot of complex factors, those clouds have indeed a greenhouse effect, but they also modify earth's albedo...

BobleBrave wrote:

parapente wrote:

As far as I can see the only real issue for the airline industry burning hydrocarbons at high altitude is ..cloud formation.The level of high altitude cloud formation does (I believe) have a strong effect of global temperatures.
Mind you I can't see what can be done about it but it might be a real issue that can be directly focused on this industry alone.

I agree, although to my knowledge there is not yet a true consensus about its overall impact within the scientific community (and it represents one of the major debate between NGOs and the industry). Models need to take into account a lot of complex factors, those clouds have indeed a greenhouse effect, but they also modify earth's albedo...

There's dispute about whether daytime contrail formation has a net greenhouse or reflective, but at night it's a net greenhouse by blocking outgoing radiation.

Interesting article here about adoption and pricing: http://www.biofuelsdigest.com/bdigest/2 ... gonna-pay/

How willing do you think pax would be to clicking a checkbox that says "buy RJF for my seat?" Right now, I buy CO2 offsets at the end of every year, but if I knew it was going directly to fixing the issue, I'd be more likely to click it.

It strikes me that this conversation is missing an important potential role for existing technology. It has been mentioned a couple of times that aircraft have become relatively fuel efficient (as I recall, a full 737 from MSP to SEA will take less fuel than an equally sized train going over the Rockies). What I have not seen in my pre-caffinated reading of this thread is discussion of a revival of some of the hub-and-spoke scheduling that we used to have.

If fuel prices rise (either through the cost of production of bio-fuel, the cost of extraction, or more likely a carbon tax), there becomes a greater financial incentive to gather passengers together and fill larger aircraft on fewer long-haul flights. The definition of long-haul may also change to re-introduce the idea of fuel stops.

Combined, we may see new aircraft designed with a large capacity, but tuned for 3,000 mile flights, shedding the weight needed for longer range capacity. As it currently stands, the 737MAX, the A320NEO and 787 are fuel sipping kings in TATL flights, but it's possible that a larger aircraft without the extra weight of TPAC capacity could de-throne them, given a reasonable expectation of a long-term rise in fuel cost (such as a carbon tax).

^That's a good point. Some of those could include open rotors for intra-Europe, a new iteration on the A300 concept, etc. As engines get more efficient, the weight-for-range penalty gets smaller and smaller, while R&D costs keep rising, so I doubt we'll see many specialized designs for this unless fuel prices really spike.

Yet another news on the biofuel front featuring SQ and the A350 :

Singapore Airlines has begun a series of biofuel flights using A350-900 aircraft on non-stop trans-Pacific flights between Singapore and San Francisco.
The project is being undertaken by Singapore Airlines in conjunction with the Civil Aviation Authority of Singapore and air navigation service providers, using enhanced flight operations and Air Traffic Management (ATM) practices along the flight route.
The programme will demonstrate the environmental and economic benefits that can be achieved through a combination of the latest fuel-efficient aircraft, alternative fuels and optimised flight operations to reduce fuel burn and carbon emissions.
The A350s taking part in the programme are being powered by a combination of HEFA (hydro-processed esters and fatty acids) – a sustainable biofuel produced from used cooking oils – and conventional jet fuel.
Altogether, Singapore Airlines will undertake 12 flights using this biofuel mix during the next three months. The first of the “Green Package” flights occurred on 1 May, linking San Francisco International Airport with Singapore Changi Airport.
“We are embarking on this initiative to help promote the use of sustainable biofuel in an operationally and commercially viable manner,” explained Singapore Airlines CEO Goh Choon Phong. “This is in line with our long-term commitment to further reduce carbon emissions while improving the efficiency of our operations.”
Singapore Airlines has ordered a total of 67 A350 XWB aircraft and 12 have been delivered to the carrier as of end-March 2017. Next year it will become the launch operator of the A350-900 ULR, which will be able to fly non-stop on the world’s very longest flights – including from Singapore to New York.

What do people think of this idea? Airlines have a checkbox on their booking site that says "power my flight with biofuel for [nominal price bump]." This would accelerate adoption and help clear the hump (lack of scale drives up costs) by allowing those of us who think it's important to vote with our wallets. Just doing a quick back-of-the-napkin, a flight from SEA-Europe for me is in the neighborhood of 60 gallons of fuel per seat. With a price delta of $2/gal, I'd pay an additional $120 (~10%) for biofuel. On local flights it would be much less than that.

Possible challenges include auditing (did that money really go to biofuel, or some marketing VP's wallet?), can't think of too many other blockers. THoughts?

Norway wants to be the first country in the world that puts battery driven aircraft into commercial service, reports the largest and respected Norwegian newspaper. (In Norwegian: http://www.aftenposten.no/okonomi/Avino ... 9664b.html).

Avinor, the state owned company that owns and runs almost all airports in Norway, has started up a project for preparing aircraft charging infrastructure at Norwegian airports. As I understand it, the aim of project is to incorporate future needs for high voltage, high capacity electricity infrastructure in airport upgrade and development plans. The National Transportation Plan 2018-2029, an important document that will be approved by the Norwegian parliament in a few weeks, includes several paragraphs on electric aircraft and financing for airport infrastructure development projects etc.

The CEO of Avinor visited Airbus in Toulouse recently, and he is quoted on that Airbus has made huge progress on the technology development needed for an all electric commercial aircraft. Passenger aircraft up to 100 seats, capable of completing a one hour commercial flight, available in about 10 years, is mentioned. (Hmmm... Speculation, possible ATR update/replacement?)

Why Norway? This is the country with the highest share for electric cars in the world. Almost 25 % of all new cars sold are fully electric (excluding hybrids). Electric cars are heavily subsidized, while taxes on fossil cars are the highest in world. This is a country where an increasing amount of car ferries (ro-ro ferries crossing fjords) runs on batteries that is charged while at port. Electricity is cheap, in abundance and produced almost exclusively by hydropower. I think the government's willingness to invest in and/or subsidize the development of electric aircraft is high. Aircraft with zero emissions is very temping. We are talking about a government that spends billions each year in order to insure that Brazil reduces the logging of the rainforests.

reidar76 wrote:

Norway wants to be the first country in the world that puts battery driven aircraft into commercial service, reports the largest and respected Norwegian newspaper. (In Norwegian: http://www.aftenposten.no/okonomi/Avino ... 9664b.html).

Avinor, the state owned company that owns and runs almost all airports in Norway, has started up a project for preparing aircraft charging infrastructure at Norwegian airports. As I understand it, the aim of project is to incorporate future needs for high voltage, high capacity electricity infrastructure in airport upgrade and development plans. The National Transportation Plan 2018-2029, an important document that will be approved by the Norwegian parliament in a few weeks, includes several paragraphs on electric aircraft and financing for airport infrastructure development projects etc.

The CEO of Avinor visited Airbus in Toulouse recently, and he is quoted on that Airbus has made huge progress on the technology development needed for an all electric commercial aircraft. Passenger aircraft up to 100 seats, capable of completing a one hour commercial flight, available in about 10 years, is mentioned. (Hmmm... Speculation, possible ATR update/replacement?)

Why Norway? This is the country with the highest share for electric cars in the world. Almost 25 % of all new cars sold are fully electric (excluding hybrids). Electric cars are heavily subsidized, while taxes on fossil cars are the highest in world. This is a country where an increasing amount of car ferries (ro-ro ferries crossing fjords) runs on batteries that is charged while at port. Electricity is cheap, in abundance and produced almost exclusively by hydropower. I think the government's willingness to invest in and/or subsidize the development of electric aircraft is high. Aircraft with zero emissions is very temping. We are talking about a government that spends billions each year in order to insure that Brazil reduces the logging of the rainforests.

Good to see that there's one country in ~200 with its head screwed on right!

News on the Taxibot front : following 737 certification, Airbus has announced that EASA has just certified the TaxiBot traction system for the A320 family. TaxiBot certification "follows an extensive testing phase at the Airbus center in Toulouse". The system is developed by Israel Aerospace Industries (IAI) and the TLD group.

LH707330 wrote:

What do people think of this idea? Airlines have a checkbox on their booking site that says "power my flight with biofuel for [nominal price bump]." This would accelerate adoption and help clear the hump (lack of scale drives up costs) by allowing those of us who think it's important to vote with our wallets. Just doing a quick back-of-the-napkin, a flight from SEA-Europe for me is in the neighborhood of 60 gallons of fuel per seat. With a price delta of $2/gal, I'd pay an additional $120 (~10%) for biofuel. On local flights it would be much less than that.

Possible challenges include auditing (did that money really go to biofuel, or some marketing VP's wallet?), can't think of too many other blockers. THoughts?

As you said, many including myself would wonder where such money would actually be going. It is an interesting idea, but when we see time and again most people looking for the least frills cheapest option to fly somewhere, I don't think it would ever be likely that more than a few people would cough up the money for something in which they don't see an immediate or direct return. Something that you would see an immediate or direct return is buying an essential service such as internet or buying premium economy and still people complain about price and don't do it.

767333ER wrote:

LH707330 wrote:

What do people think of this idea? Airlines have a checkbox on their booking site that says "power my flight with biofuel for [nominal price bump]." This would accelerate adoption and help clear the hump (lack of scale drives up costs) by allowing those of us who think it's important to vote with our wallets. Just doing a quick back-of-the-napkin, a flight from SEA-Europe for me is in the neighborhood of 60 gallons of fuel per seat. With a price delta of $2/gal, I'd pay an additional $120 (~10%) for biofuel. On local flights it would be much less than that.

Possible challenges include auditing (did that money really go to biofuel, or some marketing VP's wallet?), can't think of too many other blockers. THoughts?

As you said, many including myself would wonder where such money would actually be going. It is an interesting idea, but when we see time and again most people looking for the least frills cheapest option to fly somewhere, I don't think it would ever be likely that more than a few people would cough up the money for something in which they don't see an immediate or direct return. Something that you would see an immediate or direct return is buying an essential service such as internet or buying premium economy and still people complain about price and don't do it.

That's a good point. You'd need a slight perk (e.g. priority boarding) attached, in order to help sell it.

LH707330 wrote:

I'd be interested to know if some research has been done into fuel additives to promote or suppress contrail formation at the right times. I know USAF looked into it for the B-2 (for lower visibility), but they used some pretty nasty chemicals and it didn't work very well. I've read that some research goes back and forth on the net radiation effects of contrails, perhaps someone will find a fuel additive that's a net benefit.

You do know that for every ton of fuel burnt in a jet engine, about 1.3 tons of water is released which causes the contrails under the right conditions?



https://www.metabunk.org/how-much-water-is-there-in-jet-engine-exhaust-about-1-3-gallons-per-gallon-of-fuel-used.t4018/

Balerit wrote:

LH707330 wrote:

I'd be interested to know if some research has been done into fuel additives to promote or suppress contrail formation at the right times. I know USAF looked into it for the B-2 (for lower visibility), but they used some pretty nasty chemicals and it didn't work very well. I've read that some research goes back and forth on the net radiation effects of contrails, perhaps someone will find a fuel additive that's a net benefit.

You do know that for every ton of fuel burnt in a jet engine, about 1.3 tons of water is released which causes the contrails under the right conditions?

Yes, I do. The biofuels in the test wouldn't change the amount of water vapor created, but they would lower the soot emissions and thus reduce condensation nuclei that boost contrail formation.

See how long does it takes for industries around the world respond to problems like air pollution after industrial revolution, that would be the idealistic scenario of when industries would start react against climate change, as the climate change problem is far less localized than for example air pollution problem, and where these changes are most significant are far from population center, there are only less reasons for the industry to work on climate change problem than other problems. And given currently the main reason for industries to work on alleviating problems like air pollution is still governmental regulations, I don't think the industry can drive itself to combat climate change in at least next century.