Date: 20 Mar 97 02:38:33 From: "Fred Dunlap" <fred@cyrix.com> Organization: Cyrix References: 1
View raw article or MIME structure
cahill0@ibm.net wrote in article <airliners.1997.636@ohare.Chicago.COM>... > I'd like to know from what materials aircraft windshields and/or > canopies are typically made. Thanks. Although not really qualified to answer I'll do it anyway. Some/many/all? Big airliners use multiple sheets of tempered glass with plastic between the sheets. This is similar to your car's windshield. Cars have two pieces of 1/8 inch (2.5mm) thick non tempered glass with one sheet of plastic. 747's have (as I recall) three sheets of tempered 1/4 inch (6mm) with two layers of plastic. I believe the plastic is the same as they use on cars but thicker. They add a conductive coating to the glass to heat it when needed (controlled by the pilot I assume). These windshields have to pass the now famous chicken test where the manufacture shoots a dead (non frozen) chicken at the windshield at 400?MPH to show it shouldn't fail if hit buy a duck/goose in flight. I've heard tell it would take about a half an hour to chop through one with a fire ax. Smaller planes have smaller (thinner) windshields. Most of these are made out of Plexiglas (TM) or Lexan (TM). These are normally 1/4 inch and sometime thinner. Fighter jets use either plastic or glass. In the case of glass, they are formed and then chemically tempered. I have no idea how they form them. -- Fred Dunlap fred@cyrix.com