A lot of planes, especially airliners, are painted white. There are a lot of reasons why that is the case, which have to do with comfort, efficiency, and safety. But online, there are also rumors that the white paint is not only lighter in color but also lighter in weight, making the adoption of such a hue a cost-saving matter for the CEOs. While cost-saving will come into play, the rumor doesn’t appear to be true, according to our investigation.
The real reasons for the white paint
At the beginning of aviation, the planes kept their metallic color. Their chrome chassis is almost iconic when thinking of the early decades of aviation, but some metal planes still fly today. But a plane will experience a whole series of weather phenomena, and metals have the annoying tendency of corroding. So the paint (in any color) is a way to protect the skin of the airplane for longer. It might be expensive to paint a whole plane, but cheaper in the long run when it comes to plane maintenance. On top of the corrosion issue, a chrome plane still needs polishing, something that can be skipped altogether with paint.
White paint is also important for heat. Above the cloud line, during the day, planes are in direct sunlight for many hours. And often, they are sitting in the airport in sunlight too. White paint absorbs less heat, once again making it cheaper in the long run to keep the inside of the planes cool. The amount of sunlight exposure, as well as interaction with the elements, also affects paints differently. Colored paints tend to fade over time, something that is not an equally major issue for white paint. Once again, it is cheaper to paint the planes white.
White paint also allows for defects or damage to be spotted more easily. Cracks or dents that shouldn’t be there, leakages of oils or other internal liquids are obviously more noticeable on a livery that is white than on colorful ones.
There is another reason that is often touted as being behind the choice for white: it’s the reduction in risk of birds hitting the plane, something that can be fatal to birds and dangerous to the people on board. A study in Human-Wildlife Interactions was able to suggest that a brighter (white) fuselage, in both a sunny or partly cloudy sky, would have more contrast than a bluer one. That said, the researchers state that their work is not conclusive and does require more testing.
The plain false reason for the white paint
Now, in exploring this question online, we have found the claim that white paint actually weighs less than any other color, especially black paint. Over the whole aircraft, black paint would add the mass of multiple people to the plane, so white paint would be a sound investment if that were the case. Looking at specialized forums revealed a lot of dissenting opinions from very angry aviation fans (angry people on the internet? Surely, you can't be serious, Dr. Carpineti!). That includes people weighing the same volume of store-bought titanium oxide paints and other colored paints to show that white is actually heavier.
But we considered the possibility that maybe aviation paint could be different. A contact working in the aviation industry, who wished to remain anonymous, was able to get in touch with a leading manufacturer of paint on our behalf to ask if white paint is lighter or heavier than darker colored paint. Unfortunately, it turns out that the answer is confidential. While foiled again by capitalism, the IFLScience team is now speculating that the aviation industry is the mysterious number one glitter consumer in the world.
Our aviation expert does think that the idea that white paint is lighter comes from confusion about painting a plane in general. Planes are big and paint can add several hundred kilograms to their weight, roughly equivalent to eight people – eventually, this fact became associated exclusively with dark paints and not all paints.