The Deaf vs. The Colorblind

In article . com,
"Bret Ludwig" wrote:

Aircraft wouldn't lose the datalink because it would have a backup
battery.

a backup battery doesn't mean much when the equipment itself dies.

--
Bob Noel
Looking for a sig the
lawyers will hate

On 17 Aug 2006 09:49:04 -0700, "Bret Ludwig"
wrote:


Larry Dighera wrote:
On Wed, 16 Aug 2006 19:19:22 -0700, Sylvain wrote in
:

Larry Dighera wrote:

Please explain how a data link would be useful in controlling an
aircraft that has lost communication capability due to electrical
system failure.

the same way one would for *any* aircraft that has lost communication
capability as described in AIM 6-4-1 for instance?


Please explain how aircraft that has lost (data link and all radio)
communication capability due to electrical system failure will be able
to receive the green 'cleared to land' light gun signal upon arrival
if light guns are eliminated as suggested.

Aircraft wouldn't lose the datalink because it would have a backup
battery. But if it did they could use just one color light and three or
four Morse characters which everyone would be required to memorize.
Every pilot knows S, O, A, and N (even though AN ranges have went where
VOR should have years ago, but I digress) and most people know "V" from
Beethoven's FIFTH-da-da-da-dum.

I seem to recall being required to demonstrate the ability to identify
VOR stations by listening to the Morse coded identifier. This was
during my training for the private certificate. I astonished my CFI
by listening to the ID just once and then saying, "Ok, that's MZB (or
whatever)" without refering to the sectional chart where the morse is
given thusly -- --.. -... for MZB. He said, "How'd you do that?" I
explained I'd been a ham since I was a kid and could easily decode
those things in my head. So.....we're already supposed to be able
to do this so how come the tower guys can't talk to NORDO guys this
way?

Klein, NA7NA

These are the very colors not separable by victims of the most
common type of colorblindness.

That's probably why they were selected.

My understanding of color vision is that (aside from the rods) there are
three different kinds of cones in the eye - each optimized for a
different wavelength. This is what results in "primary colors". So, in
a sense, the primary colors are "as far apart as you can get", and
people with normal vision should be able to tell them apart the easiest.
Thus they make a good choice for discernment, where "closer" colors
are less good.

Colorblindness (or more accurately "anomolous color sensitivity") has to
do with problems with these cone types, or sometimes the lack of certain
cone types. (There are individuals who have four cone types, they see
different primary colors, perhaps even outside our range of vision.)
So, if the problem is with the very cones we've chosen to make the
colors "as far apart as possible", then those two colors are
indistinguishable. There is, in effect, a lack of redundancy in this
color choice. I don't know whether or not this was considered when the
choice was made.

I've noticed myself that the green (in airport beacons) is often not a
well saturated green, and the green (on wingtips) is often blue.
Perhaps secondary colors would work better for colorblind people while
not being hard to distinguish for normally sighted people.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

Jose wrote:
I've noticed myself that the green (in airport beacons) is often not a
well saturated green, and the green (on wingtips) is often blue.
Perhaps secondary colors would work better for colorblind people while
not being hard to distinguish for normally sighted people.

When flying at night (at a distance) I often have to watch the beacon
for a bit to discern white from green. After a few cycles I can tell
the brighter white from the dimmer green. On a sunny day the red &
white lights on a VASI often are hard to tell apart until I'm within 1
mile. I have a red/green deficiency but can tell white from green from
red well enough to have passed the signal lamp test to get a SODA.