Hi Paul.

The effects you see are from the EMI coatings used to keep electromagnetic
emissions from the instruments/displays inside the cockpit. This is part of
the
stealth package. These canopys are multi layered assemblies with lots of
different stuff to do a number of things. On a 777 for instance, the
plastic windows
have integral heaters to keep them from freexing and having degraded
mechanical
properties. In fact, if you lose the window heaters in flight, there is an
aircraft speed limit
applied to keep Q at an acceptable level. There was also a service bulletin
a while
back, because the window heaters would ignite in flight. It was pretty cool
beacause
the event occured between the window panes and you could watch it progress
across the
window.

Scott


----- Original Message -----
From: "Paul Remde"
Newsgroups: rec.aviation.soaring
Sent: Saturday, August 02, 2008 9:26 AM
Subject: canopy tint


Hi,

Below is a photo of an interesting canopy tint. It is a F-22 raptor photo
taken at Oshkosh (not by me). The F-22 seems to have an amber (blue
blocker) tinted canopy. It also appears to be mirrored - but that may or
may not be true.
http://www.avweb.com/newspics/airven...-22_raptor.jpg

P.S. - One of the gliders I owned in the past was a lovely red 1-35c with
a dark tinted canopy. It looked very cool with the tinted canopy. I'm
always in favor of anything that makes a slightly old glider look new and
cool. My best guess on the heating in the cockpit is that the more
heating will happen in the canopy itself that with a clear canopy. The
heating in the canopy should be pulled away by the air passing over it in
flight. I do remember feeling that it was a bit dark in the cockpit when
flying under dark overcast areas of cloud cover, but it was not a problem.
I didn't fly with a PDA back then so I don't know how that would be. I
imagine that a PDA with a powerful backlight like an iPAQ hx4700 would
appear brighter inside the darkened cockpit.

Good Soaring,

Paul Remde