Dette indre "vinduet" er bare en del av interiøret, faktisk, og har ingen strukturell funksjon (bærer ingen belastning). For de interesserte kan jeg klippe og lime litt fra "B737 Maintenance Manual":
A. Passenger cabin windows are located between the fuselage frames in those
areas of the cabin where passenger seating is provided. The passenger
cabin windows consist of outer and middle structural panes (Fig. 1). The
innermost pane is nonstructural and is mounted in the cabin sidewall
lining (AMM 25-21-46/401, Sidewall Lining). The outer and middle
structural panes are each capable of taking the full cabin pressurization
load. Fail-safe structure is ensured by the middle pane which is
designed for 1.5 times the normal operating pressure at 70 degrees
Fahrenheit. The outer pane is made of stretched acrylic for increased
strength. The middle pane is made of a cast acrylic. The inner
non-structural pane in the sidewall lining is made from polycarbonate.
B. The windows are designed as plug type windows subject only to the
pressure acting on them. The outer pane of stretched acrylic plastic is
rectangular in shape with rounded corners and a beveled outer edge to fit
the window frame. The pane is curved to fair with the fuselage contour.
The middle pane made of modified acrylic plastic sheet is similarly
shaped like the outer pane, but with an unbeveled edge. The middle pane
is contained in the window seal. A small breather hole is located near
the bottom of the middle pane. The window seal is a molded ethylene
propylene seal with six alignment tabs, staggered beads, and an integral
masking feature which is removed following installation. Bonding is not
required on installation of the seal.
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