Boeing has unvieled a new prototype unmanned aerial vehicle (UAV), or spy plane to you and I, called Phantom Eye which runs on hydrogen fuel. While this strange-looking aircraft will not be used for commercial flights, we often get questions such as "when will we be flying on hydrogen-powered planes?".

The answer is: "no time soon". While hydrogen is a great, clean, fuel source, it's main problem is the volume of fuel required. Compared to our current fuel, or the biofuel we will be using in the coming years, hydrogen has a lot less 'power' for each litre of fuel - and therefore a lot more needs to be carried. In effect, you'd almost need to replace the whole lower deck of an A380 with fuel tanks to power a flight of any reasonable length.

This is not to say that hydrogen might not have some benefits and projects like the Phantom Eye and Boeing's hydrogen fuel cell are providing much-needed insights into the use of such fuels. 

We've spoken about the benefits of retro-fitting winglets on aircraft before. Now, Aviation Partners Boeing, the makers of winglet devices for the Boeing 737, 757 and 767 have announced just how much these devices can save - as of tomorrow, March 5 at 19:05 in Seattle, blended winglets will have saved the world's airlines 2 billion gallons of jet fuel. This represents a global reduction in CO2 emissions of almost 21.5 million tonnes since they were first introduced in 2001.

These winglets are now flying on more than 3,700 aircraft around the world and many, such as Air New Zealand, are finding that they are saving more fuel than planned. Airbus is also getting in on the game, joining Aviation Partners to design blended winglets for their own models.

- Image from Flickr user Erwyn van der Meer.

News this week from the world of alternative fuels. ASTM has given the OK for fuels made from non-oil sources to be used in aircraft. Exciting stuff, yes? Let me explain…
 

ASTM International sets the standards for the chemical properties and production methods of jet fuel. Currently, we in the industry use “Jet A” or “JetA-1” fuel for most commercial airline flights. The key attributes of this fuel are listed in the table to the left. Obviously, this fuel comes from oil at the moment. In the last few days, ASTM has approved the use of a fuel on commercial flights that doesn’t come just from oil.

Their latest specifications allow for, among other things, a 50% mix of fuel made from the gas-to-liquid process to be used. This process, also known as GTL, takes natural gas and turns it into a liquid fuel. Just like the name suggests! In fact, this fuel standard allows any fuels using the  "Fischer-Tropsch" process to be used in a mix with traditional fuels.

Now, gas-to-liquid fuel has some advantages over normal old fuel made from oil – it has lower particulate emissions and a slightly higher energy density (you can fly a little further on the same quantity of fuel). But of course, it is still using fossil fuels and the production of the fuel takes energy and results in CO2 emissions as well.

But it is a good step. Now that ASTM International have approved this fuel mix, the door is opened a little wider to the real environmental pay-off that comes with sustainable biofuels.

Jennifer Holmgren, Honeywell UOP, speaking about aviation biofuels at the Summit

(Photo by Justin Hession/Getty for the Air Transport Action Group)

We’re getting to the end of the day and it has been tremendously exciting to see all the delegates interacting and listening to the comments from the sessions.

One of the major topics focused on this year has been the prospects for alternative fuels for aviation. It’s a little known fact that the industry now has a target for 10% use of biofuels by 2017, which would be an amazing achievement. When I worked on the UK Sustainable Aviation project in 2005, we were told that kerosene would be the only game in town until at least the middle of the next decade. Even the 2006 Update, which did reference alternative fuels, concluded that despite some advances “Notwithstanding the above developments, kerosene is a safe, high energy density fuel and is likely to remain the fuel of choice for the foreseeable future.”  Little could we have known that just three years later a plane would fly with a biofuel mix, and that not only would it prove to be viable, but it would in fact prove to burn even cleaner than kerosene.

There remain many technological and logistical challenges of course before we see biofuel playing a significant role. But the debates in the hall today showed that aviation has faced similar challenges before, and has conquered them.  The Solar Impulse project points the way – albeit even further in the distance – to an even more exciting future. Completely carbon-free flight.

It is events like this which show that the aviation industry has lost none of its pioneering spirit, even in these difficult economic times. Let’s hope the politicians make similarly far-sighted decisions later this year.

As a Brit living in Geneva I always enjoy my trips to London. This week I popped into the Science Museum to see its exhibition on aviation and the environment called 'Does Flying Cost the Earth?'

I hadn't been to the Science Museum since I was an eight year-old living in London and I had forgotten how impressive it is. I became completely absorbed in the 3rd floor exhibition on flight, which includes Amy Johnson's airplane Gipsy Moth. 

Anyway, I found my way to the far end of the ground floor where the exhibition sits. It looks at how aviation impacts on climate change and what can be done to reduce aviation's 2% share of global carbon emissions. The Science Museum exhibition also has a complementary website that makes the same information about aviation and the environment available online. 

The exhibition looks at how we can save fuel and reduce emissions right now, but what I enjoyed was its take on some of the technologies that could be available in 20 to 30 years time.

Many of the technologies highlighted focus on saving weight. Less weight = less fuel used = fewer emissions. Engine makers are developing lighter but stronger turbine blades, and plane makers are combining carbon fibre with traditional materials like plastic to make lighter planes.

There are also some visionary ideas to make planes more aero dynamic. One such is the blended wing aircraft. The aircraft becomes one big flying wing, improving airflow to save fuel, which would significantly reduce emissions. But there would be fewer windows.

And the exhibition looks at alternative fuels to traditional jet fuel. Various possibilities are discussed including liquid hydrogen and making fuel from algae.

I thought the exhibition was very balanced. It doesn't try to hide the fact that planes contribute to climate change, and explains exactly what causes aviation's climate change impact. The exhibition has some excellent animations that bring the complexities of climate change to life. It takes a realistic view of whether the new technologies will be feasible or not and highlights the problems as well as the benefits.

There is also a great interactive game where you upgrade your fleet with the latest technologies and it shows if you are reducing emissions in the light of increasing passenger numbers.

I disagreed with some things. I thought the exhibition undersells many of the amazing technological advances being developed. For instance, it downplays the potential of algae as a replacement for kerosene. I think algae offers very real possibilities for a carbon-neutral industry and would not compete for land with food crops. It also doesn't deal with the technological advances in navigation and operations that enable planes to fly more efficiently and use less fuel.

But all in all a great exhibition and anyone who flies and is concerned about the environment should go and see it.

The exhibition runs until 2nd November so if you are passing through London and are interested in aviation and climate change go take a look.

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Last Friday was a busy day for my colleagues in New Zealand and on the West Coast of the USA, as the first-ever ASPIRE flight took off. ASPIRE stands for Asia and South Pacific Initiative to Reduce Emissions, and the primary actors are the ANSPs Airways New Zealand, Air Services Australia, and the Federal Aviation Administration. Airlines Air New Zealand, United Airlines and Qantas, along with Boeing and the airports involved, are also partners in the project. Friday's demonstration flight from Auckland to San Francisco enabled the ASPIRE partners to get a clearer understanding of the potential fuel savings to be made.

Essentially, the flight was the first to combine the various advances that have been made over the past few years in routing aircraft through the sky, from User Preferred Routes to Continuous Descent Approaches. This 'gate-to-gate' concept offers the potential for airlines to save millions of tons of CO2 once it is fully rolled out. Friday's flight saved an estimated 4600 litres of fuel - around 4% of the flight's loading.

The Airways New Zealand website has some excellent information on the various phases of the green flight. The comparison between what used to happen and what took place on Friday is particularly interesting. For some news coverage of the 'green flight', Television New Zealand has an article and related video.

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