Editing Fuselage (section)

== Windows ==

[[Cockpit]] windshields on the [[Airbus A320]] must withstand [[bird strike]]s up to {{cvt|350|kn|km/h}} and are made of [[chemically strengthened glass]]. They are usually composed of three layers or plies, of glass or plastic : the inner two are 8&nbsp;mm (0.3 in.) thick each and are structural, while the outer ply, about 3 mm thick, is a barrier against [[foreign object damage]] and [[Abrasion (mechanical)|abrasion]], with often a [[hydrophobic]] coating. It must prevent [[Anti-fog|fogging]] inside the cabin and de-ice from {{convert|-50|C}}. This was previously done with thin wires similar to a rear car window but is now accomplished with a transparent, nanometers-thick [[coating]] of [[indium tin oxide]] sitting between plies, electrically conductive and thus transmitting heat. [[Curved]] glass improves [[aerodynamics]] but [[sight]] criteria also needs larger panes. A cockpit windshield is composed of 4–6 panels, 35&nbsp;kg (77&nbsp;lb) each on an [[Airbus A320]]. In its lifetime, an average aircraft goes through three or four [[windshield]]s, and the market is shared evenly between [[OEM]] and higher margins [[Aftermarket (merchandise)|aftermarket]].<ref name=AW161128/>

[[Cabin (aircraft)|Cabin]] windows, made from much lighter than glass stretched [[acrylic glass]], consists of multiple panes: an outer one built to support four times the maximum cabin pressure, an inner one for redundancy and a scratch pane near the passenger. Acrylic is susceptible to [[crazing]] : a network of fine cracks appears but can be polished to restore [[optical transparency]], removal and polishing typically undergo every 2–3 years for uncoated windows.<ref name=AW161128>{{cite news |url= http://aviationweek.com/mro/what-passenger-cabin-windows-will-future-airliners-have |title= What Passenger Cabin Windows Will Future Airliners Have? |date= Nov 28, 2016 |author= Alex Derber |work= Inside MRO |publisher= Aviation Week}}</ref>