Why are planes painted.?

Question

I'm talking about metal aircraft.1 gallon of paint weighs about 10 pounds.Say it takes 1000 gallons of paint to cover a 747. That 10,000 lbs extra weight the aircraft is carrying and I imagine there is some drag compared to an unpainted plane.Airforce C141's at one time were not painted.10,000 lbs lighter means less fuel and or more passengers.I realize people identify with an aircrafts colors, but can we afford to waste fuel just to look good.

Answer 1

First of all for the appeal because bill gates is not going to want to fly on a plane that looks like s*hit

It will also keep the rain out and waste a lot of $

Answer 2

probably to act as a sealant to help keep the plane pressurized

Answer 3

mainly to protect the metal from rust and corrosion.  also a smooth coat of paint helps it slip through the air more efficiently.  Just like your car, if you keep it clean and waxed, it will get better gas mileage.

Answer 4

no one wants to cruise around in a giant flying d***o

Answer 5

1. a painted surface will not corrode, and that will keep the aircraft looking better, longer with less maintenance. Corrosion especially around the rivets and abutment areas will shorten the service life of the airframe, the paint or sealer around those areas is necessary for the aircraft to live up to its service life expectation.  You have to have a sealer if you do not have it painted/sealed.

2.  It is identification and advertising for the airline

3.  the paint does not weigh as much as it did in the can, because as it dries, the solvent, which is mostly water in the new paints, the pigment weighs about 1/5 of the wet paint.

4.  A painted surface has a smaller coefficient of drag, it is not much, but over the area of a airliner, at the speeds they fly, .78 to .82 mach, it is actually more efficient.

Good question, actually military aircraft that are subsonic are usually painted for the same reasons, although there are exceptions.  Much of the new supersonic aircraft are composite,not aluminum, and the covering is as much a part of the construction as the adhesive, bis-gma resin.

good question, have a good day