Despite the fact that each airline has its own corporate color scheme – livery, the vast majority of aircraft at airports are almost always white. To increase awareness or as part of an advertising campaign, part of the fleet may be painted in bright colors, but as a rule, it is no more than 1-3 aircraft from several dozen (or even hundreds) that the company has at its disposal. But why is white so good?
Why paint them when you can polish them?
To begin with, let’s find out why planes are painted at all.
Painting gives the aircraft a neat look and also protects it from minor scratches, rusting, jet fuel spills, etc. But why do you need paint, if the same effect can be achieved without it? After all, a few decades ago, some airlines preferred to minimize the paint. American Airlines planes in particular had a distinctive silver appearance, as much of their fuselage surface was polished aluminum.
The advantage of an unpainted aircraft is considered to be low weight and, therefore, a reduction in fuel. For example, a 0.1 mm thick paint layer on a Boeing 737-700 adds 81.2 kg to the weight of the aircraft, and in the case of a Boeing 747-400 this figure is 251.7 kg. This equates to 1 – 3 passengers who do not pay for tickets but attend each flight.
Nevertheless, painting is still more profitable than polishing: aircraft paint is renewed every 4-10 years, but polished aircraft must be placed in the hangar 3 times a year, well washed and waxed using mechanical polishing machines. Otherwise, the surface becomes dull and the protective effect of polishing disappears.
Boeing estimates that total operating costs for painted aircraft are 0.06% to 0.3% lower than for polished aircraft. Another disadvantage of polishing was passenger complaints that the light reflected from the fuselage irritated the eyes on sunny days.
Modern aircraft models contain less and less metal and more and more composite materials that can be painted but not polished. Due to these circumstances and the aforementioned disadvantages, polished planes became a thing of the past, and painting became undisputed.
Why is white so good for airplanes?
- Ease of maintenance. On a white background, it is easier to detect any cracks, dents and other surface damage, as well as to detect drops of oil or any other liquid;
- Cost reduction. Painting the aircraft in bright colors increases the total cost of painting from $50,000 to $200,000, depending on the size and pattern of the aircraft. Bright patterns fade faster, which is why you need to renew the cover more often. In addition, many airlines periodically sell their aircraft to other carriers. You can sell a white aircraft faster and at a higher price, because the buyer does not have to spend time and money on repainting;
- Reduced temperature stress. When flying at an altitude of about 10 km, the air temperature in the sea is on average between -40 and -60°C, and at the airport it exceeds +40°C. White reflects more sunlight than any other color, helping to heat the fuselage surface. This means that the thermal expansion of the metal will not be so pronounced, which has a positive effect on the durability of the coating.
- It is easiest to detect white debris from the air during search operations after a crash landing or crash. Exceptions are airplanes that mostly fly in snowy polar regions, so they are often painted red or orange;
- The white color is clearly visible in the sky, giving the birds more time to avoid the aircraft. Thus, coloring in this color reduces the probability of collision with birds.