Why are most aircraft painted predominantly white?
Aircraft liveries, or the designs painted on the exterior of aircraft from the nose to the tail, are a way to identify to which airline the plane belongs. You may be able to easily recognize an aircraft flying miles overhead due to the color scheme of the tail, and the airline name across the fuselage.
Airlines spend huge amounts of money on this branding exercise, and when liveries are updated, they are the subject of much debate as passengers decide if the new design is an improvement on the old one. Though there are some unique and eye-catching creations, one factor of the liveries across most airlines is the same — they are predominantly white.
Is this just a coincidence?
Well, no — here's why.
One reason is that white paint reflects sunlight, helping to keep aircraft cool and minimize any potential damage from solar radiation.
To keep aircraft as light as possible in order to reduce fuel costs, planes are made from composite materials, which need protection from the heat of the sun, as MIT Aeronautics and Astronautics professor R. John Hansman told Business Insider. The cooler the plane is from the paint protecting its exterior, the less cooling (and subsequent expense) will be required inside.
Although a tin of paint by itself might not weigh much, airlines need a lot of paint to cover an entire aircraft — especially a Boeing 747 or Airbus A380. This can add half a tonne to the weight of the plane. This is another reason airlines favor minimal, plain designs — adding lots of different colors and layers for a snazzy yet complex livery costs more to paint, and therefor weighs more to fly each and every time the aircraft takes to the skies.
Like a car or luxury leather sofa in your living room, white does show the dirt. You may have noticed some older white aircraft looking particularly dirty, especially around the doors where the aerobridges connect with the plane. You might think white color schemes have a big downside of making planes look dirtier than they might be in a darker color, but the white paint does help with aircraft maintenance for this exact reason. Cracks and dents in the aircraft fuselage can be more easily spotted on white paint.
Airlines do sometimes paint entire planes with nonwhite designs, such as the famous Air New Zealand All Blacks Boeing 777 aircraft. While these are expensive to paint and do not offer some of the protection that white paint does as mentioned above, they are used for promotional purposes, which helps to offset the increased cost.