Wait! Don’t paint that plane.

We’ve all seen planes (if you haven’t click here) and some of us flew on them. You stand at the gate looking in admiration at the beautiful machine. Fascinated by the curves on its body and the shear size of its engines, or maybe that’s only me. But I am sure that most of us have noticed that airplanes tend to be nicely painted with the airline colours. It makes it look good, acts as marketing material and adds to the flight experience.

But there is also a technical reason why airlines paint planes, and that’s to protect the body from corrosion. As the paint fades away though, planes get repainted. And then repainted and then repainted. And after some time, believe it or not, all this paint has added weight on the plane. A Boeing 747 for example when fully painted adds 250Kg of paint (see here). So paint it only twice and you have half a ton extra on the plane. If you remove 500Kg off a 747 you can reduce carbon emissions by 0.2% OK it’s not much, but it doesn’t take much effort not to paint a plane.

Or does it? In order to protect the plane against corrosion once the paint is gone, we must polish it. If we polish our 747 and put some airline logos on it we end up with only 25 Kg of paint on it, so quite a good saving.

Now think about those airlines which charge you a lot of money for that extra kilogram you have in your bag. Every extra kilogram burns some extra fuel and that costs a lot of money. And since the major cost for airlines is fuel, it pays to take 250Kg off your plane. So if I was a CEO of an airline, you would hear me shouting “Wait! Don’t paint that plane.”

Sustainable Energy

January 6th, 2009

10 responses

10 responses


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Harry

hahaha I love that.

January 8, 2009 9:17 am

Harry

as in “if you haven’t seen a plane, click here”

January 8, 2009 11:25 am

Jack

Ok, so this is a bit of a flawed argument. Saving 0.2% on the efficiency of an aircraft would indeed lead to the emissions of all commercial aircraft entering and leaving the UK of 0.72Mt of carbon dioxide. This saving is not entirely insignificant since the aircraft emissions have an increased effect on the atmospheric conditions in comparisson to cars.

The aircraft efficiency is related surface smoothness and hence polishing is necessary. A polish is typically composed of a fluorinated co-polymer wax emulsified in a water/heptane/toluene/ethyl acetate/isoparifinic mixture. This mixture is different to that used in even the most polluting solvent-varnish paints. LCA has found paint to have a very, very small environmental impact and in fact often painting is linked to a reduction in overall impact. The same cannot be said for the polish solvent production methods, since they often involve high temperatures and pressures, and the use of toxic heavy metals. The production methods not only lead to carbon dioxide and other GHG emissions but, if any of the product or inorganic or organic molecules used in its synthesis are lost into the environment (as is inevitable) then their effect can be devestating.

Furthermore, the saving by polishing is of little significance when the calculation method is considered. The 0.2% saving would have been calculated by deducting the fuel used in the low paint regime from that used in the re-painting regime. These values are calculated based on the fuel consumed by a 747 operating at mean efficiency with a mean load. So lets consider the load, the mean weight of an adult man is 70kg and the mean weight of an endomorphic (fat) man is 141kg. This gives a difference in mass of 71kg, using the value of 475kg of paint saved by polishing shows that the increase in efficiency is offset if just 7 endomorphic people board the aircraft! This means that passenger mass is substianially larger than the paint mass (26,250Kg mean passenger cf. 500kg paint mass) especially when you consider that some 32.2% of the population are in the endomorphic category. Perhaps therefore the CEO of an airline should be shouting “no lose some weight” to all the overweight passengers.

January 8, 2009 12:58 pm

Jack

http://www.sveff.se/Branschinformation/LCA_eng.pdf

January 8, 2009 1:01 pm

admin

I have always believed that passengers should be allowed a combined weight for themselves and their luggage. But it seems like it is difficult to implement due to strategic and possibly legal reasons. The fact is however that a CEO shouting “lose some weight” is probably not good for business, and since the CEO doesn’t really get a say on who will get on the plane maybe they should focus their attention on their plane. If they can offset the effect of 7 endomorphic people then why not.

When the airlines reduce their plane weights, they don’t have to pay carbon credits for their emissions. If an LCA somewhere says paint is much better for the environment, The CEO doesn’t care. So unless the carbon markets cover polishing products and thus price in the negative environmental effects, or some of them at least, and the fuel + carbon credit saving by making the plane lighter is actually less than what it costs to but the polish, then you will see paint on the planes. But until then it’s “Wait! don’t paint that plane”.

January 9, 2009 12:43 am

Jack

According to http://www.boeing.com/commercial/aeromag... “net operating cost of polished airplanes is slightly more than that of painted airplanes”. This is the same source as you (admin) got your data from!

Also: “While the lighter weight of a polished airplane saves fuel costs, as shown in (table 1), this savings is more than offset by the higher cost of washing, polishing, and painting a polished fuselage throughout its service life (table 2).”

Consider that the same source says that polished planes have to be washed twice as often as painted planes. This must present an environmental and economic impact in terms of water and detergent usage. I speculate that this environmental impact has not been considered in this article. The article describes how some paints contain Cadium and other heavy metals that are potentially released by painting (though entrapment methods are good) yet also indicates enviromental problems from the volatile organics released from polish (esp ozone depletion). Again the article does not consider the effects of producing such solvents on the environment and the potential of the production methods to release heavy metals.

Commercial aircraft are designed with efficiency in mind and hence improvements that are proposed by for example polishing not painting have a very limited effect on the aircrafts overall fuel consumption. The requirement for endomorphic passengers to buy two tickets is becoming increasingly common in the continental US. This trend will probably be reflected globally as airlines will need more than ever to extract every penny of profit from travellers.

As for carbon credits at present only European airlines have to participate in the scheme. The only major commercial carrier to polish their aircraft is AA. This practice has existed at that airline for a long time and has become a trade-mark, initially the decision was made based on the mass of the aircraft. It is now however according to boeing agreed that polishing does not save the airline money, it costs them. Surely if the carbon credits system meant that it became more cost effective to polish than paint then more (atleast one) European airline(s) would turn to polish or be considering it (no evidence in any aviation blog/google/airline website to suggest this). This lack of interest suggest (or is evidence) that it is not the case that polishing combined with carbon credits offsets additional costs,

As a final point much research is looking at improving paints in terms of mass and paints such the Aeo wave series (http://www.coatingsworld.com/articles/2008/08/aerospace-coatings.php) will mean less re-painting is necessary and hence the cost of painting relative to polishing will be further reduced.

January 9, 2009 1:50 pm

admin

Well done with your long comments!

It’s good that you realised by the end of your comment that it all depends on carbon prices. Even though there are currently no suggestions in the media that airlines are not considering polishing their planes, that does not mean that they are not. You can extend your research a bit more and realise that there is currently an issue with carbon price signals, as no one really knows how much they are going to cost. If they are expensive enough, I trust that airlines will be looking into it.

You should also know that Australian domestic aviation will be covered under their emission trading system and will soon have to pay up on their emissions, so it is not only within the EU, and it will probably start spreading.

I would be interested to find out what you mean by increasingly common, when talking about buying 2 tickets if you weight a bit more. How many flights per day have this requirement? and out of how many that operate?

January 9, 2009 3:45 pm

Jack

Please delete above and post this…thanks Jack

Lets take the case of the proposed maximum 240 Euros per tonne of carbon (see Fitzgerald, 2007, CESifo Forum 1/2007, Report:RM4465) this means that the saving passed onto the entire UK fleet by polishing their aircraft is some 172,800,000 Euros across the fleet that amounts to an annual saving of 360 Euros per aircraft. Given that it takes approximately 16 man hours (http://www.nordicaero.se/upload/Dino-PDF-listning/New%20NordicDinoII-777brochure.pdf) to simply wash an aircraft and that this is performed usually at every B-check, so once every 4 months is not uncommon,(http://www.airliners.net/aviation-forums/tech_ops/read.main/205874/) this for painted jets. This means that labour costs alone for cleaning a painted jet are (bases on minimum wage) 102.44 Euros, the cost of the extra cleaning required with polishing amounts to 409.67 Euros and hence negates the saving made by carbon trading. This estimate does not include the hire of machinery or the cost of electricity.

On your point about Australia, that is new to me. The likelihood of the scheme spreading is reduced by the current economic climate and the protectionist attitude Obama seems to adopting in dealing with it. This means that the USA is less likely that ever to agree to tariffing on its airline. This in turn gives US commercial airlines an unfair advantage and most probably means the scheme will fail to get off the ground or the US landing rights will be withdrawn. I think you will agree the latter of the two is far less likely. (http://economiclogic.blogspot.com/2008/03/carbon-credits-for-airlines.html).

Finally, Southwest Airlines in the US definately implements a ‘fat-tax’ asking obese passengers to purchase to seats. A basic internet search will reveal that there is growing public opinion for such moves in the USA and abroad with a tax becoming common on other US internal flights. Only the Canadian courts have ruled this tax to be unfair and in any case such a ruling will only apply to AirCanada.

January 9, 2009 6:01 pm

admin

On Obama and the US: Obama has seemed to promise to get the US out of the economic rut by creating a massive green industry. So not sure about how anti-environment the US will be.

The world seems very confident that we will be getting out of the economic slum by mid-2010. You can see Gordon Brown for example promising more for the environment even though the UK economy is suffering. So I believe that there is still hope for the scheme to spread. Initially maybe through domestic aviation only, but with time things will improve.

As for your calculation for how much polishing can save money, assuming you are correct with your prices, then the airlines would probably not polish their aircraft. I am guessing AA justifies it as marketing costs. I guess it is still an option that’s there in case carbon prices really hit the roof. We have to wait to find out!

January 9, 2009 6:18 pm

Jack

To be frank carbon prices will never hit 240 Euro per tonne since this would amount to an annual carbon bill of 90,000,000,000 Euros annually for british aviation, this is an additional 187,500 Euros per flight or circa an additional 468 Euros on top of each ticket (assuming average load of 400). This would make the cost of flying prohibitive and have an impact on the world economy as a result. If the airlines were to absorb this cost and maintain current ticket prices, lets say BA accounts for 15% of those flights, there bill would be 13,500,000,000 Euro or £12,081,877,100 (assuming current exchange rate) this means that BA’s current pre-tax profits would cover just 5% of their carbon bill. So BA profits would have to increase 20 fold simply to meet their carbon bill. So a carbon price that high would certainly spell the end for commercial aviation.

This means a lower tariff would be set, so less money would be saved by polishing in terms of carbon credits and hence polishing will become even less likely.

January 9, 2009 6:59 pm

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