Page manager Published: Mon 17 Sep 2012.

When will all aircraft go green?

Pilot Henrik Ekstrand spends more time in front of the computer than in the cockpit. It saves his employer several million SEK a year.

​A criticized and economically struggling aviation industry does what it can to save on expensive fuel and reduce emissions. So what is more important, money or the environment?
“The environment,” says Henrik Ekstrand without hesitating. It was more a matter of his, and not the airline's, personal interest in research and the environment that led him to pursue his PhD in industrial engineering at Chalmers five years ago. Still, his employer, Novair, who finances his PhD studies, is cashing in on it. Henrik Ekstrand's research has contributed to a roughly five percent decrease in the airline's fuel consumption, equalling savings of around five million SEK per year per airplane.
“It's a win-win situation. Both the airline and the environment benefit from it.”
 
In the early 2000's, energy prices constituted a very small part of airline budgets; fuel costs are now soaring, and account for 30 - 40 percent of their expenses, explains Henrik Ekstrand. The three planes in the Novair fleet, for example, slurp as much as 300 million SEK of fuel a year. At the same time, we are flying more and more. New statistics show that the number of Swedish passengers grew by 11.6 percent last year alone - and on a global scale, the airline industry is the part of the transport sector where emissions are rising fastest, having more than doubled in the past 20 years. The airline industry is often criticised as being a major culprit in the climate crisis, and perhaps not without reason. But the picture is often exaggerated, a Sifo survey from 2010 points out.
 
“According to [this survey,] 27 percent of Swedes think that aviation represents more than 20 percent of total global emissions. In reality, it is about two to three percent, a fact which only a minority managed to pinpoint. In Sweden, however, the figure is slightly higher, around four or five percent. - And when people hear this, they are horrified. Why is our performance so bad in this respect? The simple answer is that here in Sweden, because we have the lowest carbon emissions in general, planes account for a higher percentage,” says Henrik Ekstrand. The myths surrounding the airlines and emissions are many, he says. The train and bus, of course, are more climate-friendly options; the car most certainly is not.
 
“When we fly full charter flights from Gothenburg to Greece, we use .022 to .023 litres of fuel per passenger per kilometre. This means you would need to put five people in the car travelling to Greece to make it more climate-friendly.”
Short flights, however, consume more fuel. The leg from Gothenburg to Stockholm requires around .05 litres per kilometre per passenger, for example. Although, just because you're flying further or in a more fuel-efficient way doesn't mean that the actual amount of fuel consumed will be small.
 
It's a long way to Thailand, and planning a winter holiday there will never be a climate-smart option - at least not until planes run on algae. Yes, you read that right. Oil extracted from single-celled algae is one of the hottest options among the renewable jet fuels. Test flights using this and other biofuels have already begun.
“The problem is that it's too expensive to produce at this point, but it's definitely the way of the future. We're going to see a smooth transition, with biofuel being mixed more and more with traditional jet fuel.” But Henrik Ekstrand is not expert in this particular field – saying he follows this type of research, as well as the development of new aircraft materials and engines, from the sidelines.
 
His own research is centred on the two other areas that can be improved to reduce fuel consumption - how aircraft are flown and how the air traffic is controlled from the ground. In a nutshell, how to achieve the perfect green flight, given the circumstances of today. “A flight can be divided into several parts: ground operation, takeoff and climb, cruising, planned descent and landing. Looking at it that way, there are lots of small ways to save here and there, and every little bit helps.”
Henrik Ekstrand talks about the obvious things that Novair has introduced - everything from not taking onboard more fuel or cabin water than is needed during a single flight or flying a little slower and putting as little strain on the engines as possible. But the airlines have no control over the routes – and nor do individual countries. This is why the European Commission is introducing a programme to modernise the European air space, SESAR, where aviation agencies and airlines cooperate with one another.
 
The goal is to share airspace among all countries and make it easier to allow aircraft to fly more directly to their destinations. Henrik Ekstrand is involved in a number of SESAR projects, including research into "curved" green descents into Gothenberg’s Landvetter Aiport using GPS, which shortens the flight by a several dozen kilometres.
- The really major environmental savings can be made at the destination and departure airports, in that order, he says, and asks:
- Have you ever flown to London? You know, a pilot never flies directly into Heathrow, but to a radio beacon in Lambourn a good distance away. There the plane has to wait for ten or fifteen minutes. A typical example of how fuel goes to waste.
 
In the future, the airline industry will become better coordinated. Instead of circling around above London, the plane will wait longer at Landvetter Airport. The challenge is to get air traffic control systems at the respective sites to communicate with each other. "Pull off the throttle as soon as you're off the ground, accelerate at the right speed and be sure to pull in the wing flaps (which lift the plane at lower speeds) as early as possible." - this is Henrik Ekstrand's advice to pilots wishing to save fuel and reduce noise during takeoff. Noise is important. Henrik Ekstrand is interested in this - noise versus emissions.

It is illegal to fly over densely populated areas near Swedish airports, a prohibition which often requires detours at both takeoff and landing. The takeoff from Landvetter Airport to Stockholm, for example, is 35 kilometres longer than it would otherwise.
"Sometimes it's warranted, sometimes it may be questionable, but modern aircraft make considerably less noise than their predecessors." His conclusion is that, on a national level, we should look carefully at our priorities.
"The problem is that noise is measured in seconds, while the carbon dioxide emissions remain in the atmosphere for at least a hundred years."
By: Lars Nicklason Photo: Novair
 
 
Facts:
Henrik Ekstrand is expected to defend his thesis this winter at the Department of Applied Mechanics. He has an additional degree in mechanical engineering from 2003.
 
The text was previously published in Chalmers Magazine 2/12

Page manager Published: Mon 17 Sep 2012.