For some reason I've always remembered that Concorde electrically heated its windows using a laminated layer of gold: https://www.heritageconcorde.com/concorde

For some reason I've always remembered that Concorde electrically heated its windows using a laminated layer of gold: https://www.heritageconcorde.com/concorde-fuselage-windows https://www.heritageconcorde.com/concorde-fuselage-windows