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I got checked out in the G1000 172 at my flight school just so I could schedule to fly when the two steam gauge 172s were booked. I'm very impressed by the G1000, but I can't wear sunglasses when I fly the NAVIII. This is with the avionics dial on the lighting panel turned all the way up.

Does anyone else have this problem? Is it my sunglasses?

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    $\begingroup$ Are they polarized? $\endgroup$ Commented Aug 9, 2015 at 0:34
  • $\begingroup$ They are indeed $\endgroup$
    – flyinghigh
    Commented Aug 9, 2015 at 0:35
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    $\begingroup$ The FAA is on record as being against polarized sunglasses. See page 5 of the following publication: faa.gov/pilots/safety/pilotsafetybrochures/media/sunglasses.pdf, which I should have read but didn't and now have a pair of sunglasses that are useless for glass cockpits. $\endgroup$
    – Terry
    Commented Aug 9, 2015 at 1:48
  • $\begingroup$ Related question $\endgroup$
    – DeltaLima
    Commented Aug 9, 2015 at 6:19

1 Answer 1

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The screens are LCDs, which have a polarized filter layer over them. That layer is usually placed at a 45° so they are misaligned with your polarized sunglasses which are aligned vertically. You can confirm this is the problem by turning your sunglasses at different angles and see if the screen changes.

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    $\begingroup$ The polarization on the sunglasses is probably the issue. It's not a good idea to fly with polarized sunglasses on anyway. It can reduce the glare off an airplane when that glare might be the queue that saves your life. $\endgroup$
    – ryan1618
    Commented Aug 9, 2015 at 2:07
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    $\begingroup$ Gratuitous extra info: A polarization filter is a key part of an LCD. Liquid crystal itself can only change the polarization of the light going through it; it's the polarization filter that then blocks some of the light making pixels appear light or dark : en.wikipedia.org/wiki/Liquid-crystal_display#Overview $\endgroup$
    – rakslice
    Commented Aug 9, 2015 at 7:37
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    $\begingroup$ @RyanBurnette: Ahem "cue" ;) $\endgroup$ Commented Aug 9, 2015 at 13:21
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    $\begingroup$ @DavidRicherby: Planes are made of metal, but usually are painted, too. The paint generates polarized glare. About the LCD: Of course, polarization is the principle of work inside an LCD. But you can convert the linear polarized light coming from the display into circular polarized light, which is not affected by polarizing sunglasses. As said, a simple foil on top of the display is enough. My opinion: The blue of the sky is also partially polarized and so shaded by glasses. Clouds and other objects stay bright and are better visible, which is a clear pro for polarized glasses. $\endgroup$
    – sweber
    Commented Aug 9, 2015 at 17:55
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    $\begingroup$ First off, metallic paints actually don't have any metal (there are some paints with high metal content to make them conductive for electronic shielding, but they're not very pretty). Metallic silver paint is just a specific shade of grey in a gloss base with mica particles suspended in it to provide that metallic glitter. So on a plane painted silver, the reflection is 100% paint. The mica flakes can cause a scatter effect on polarization because they're oriented at different angles, but it's minor compared to the reflection off the high-gloss surface. $\endgroup$
    – KeithS
    Commented Aug 12, 2015 at 18:37

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