Why are airplanes white?

My daughter innocently asked that question the other day, and I gave
her the usual "because white reflects heat better" answer -- but that
really doesn't add up, does it?

Automobiles, motorcycles, boats -- you name it -- all come in a
rainbow of colors. Why are 99.5% of all planes (except for some cool
old classics and some neat homebuilts) white?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote in message
ups.com...
My daughter innocently asked that question the other day, and I gave
her the usual "because white reflects heat better" answer -- but that
really doesn't add up, does it?

Automobiles, motorcycles, boats -- you name it -- all come in a
rainbow of colors. Why are 99.5% of all planes (except for some cool
old classics and some neat homebuilts) white?

That really is the answer, though.

Fiberglass airplanes almost demand it. If they get too hot, the epoxy gets
hot, and gets weak. Very weak.

Other airplanes get too hot to be comfortable in the summer. The heat of
being parked in the sun also lets the interior get so hot that it damages
expensive avionics.
--
Jim in NC

Fiberglass airplanes almost demand it. If they get too hot, the epoxy gets
hot, and gets weak. Very weak.

Yep, I fiberglass has to be a lighter color -- that makes sense.

Other airplanes get too hot to be comfortable in the summer. The heat of
being parked in the sun also lets the interior get so hot that it damages
expensive avionics.

My interior gets to over 121 degrees (the max of my panel thermometer)
every time I park outside in the summer (unless I put the window
reflectors in, of course), and my plane is white.

I suppose it would be worse if it were black, but blue or red or
silver (like the new Cirrus) sure wouldn't hurt.

I think owners are afraid of harming their resale value, and white is
the most "neutral" of all colors. I would like to see more
imagination in our aircraft -- heck, it might even attract new people
to aviation?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote

My interior gets to over 121 degrees (the max of my panel thermometer)
every time I park outside in the summer (unless I put the window
reflectors in, of course), and my plane is white.

I suppose it would be worse if it were black, but blue or red or
silver (like the new Cirrus) sure wouldn't hurt.

It is amazing how much hotter ANY color gets.

I recall that even a light color like yellow is something like over 30%
hotter than white.

Red? Dark blue and black?

You REALLY don't want to go there. g

I saw a chart one time, and it gave the interior temperatures of a boat (?)
painted different colors, I think. I could not find it now. You might want
to find it, if you can. It is a real eye opener.
--
Jim in NC

First thought that came to mind: It's cheaper, somehow.

Barns came to traditionally be painted red because a hundred years ago, that was
the cheapest paint color. Looking at the GA planes of 50 years ago, reds and
yellows predominate.

Why did the fleet center on white? Perhaps there was an advance in paint
technology that resulted in lowering the manufacturer's costs if the planes were
painted white.

For instance, today, when you go to the hardware store to buy a gallon of paint,
the store starts with a gallon of *white* paint. They then add pigmentation to
make it the color you want. Make it a few tens of thousands of gallons a year,
and the cost of the pigment goes up. Paint white, save the extra cost.

It may even be tied to the transition from fabric-covered planes to all-metal
aircraft. You can brush/roll-on colored dope and the plane will look great, but
there's no weave for the paint to soak into, on a metal surface. Metal surfaces
want to be sprayed, and white paint is probably easier to monitor for
consistency during the process (spotting thin areas, detecting sags, etc.).
And, it could be that somehow the formulations of white paint in the '50s were
somehow more suitable for spraying than other colors.

Ron Wanttaja

On Nov 3, 5:51 pm, Ron Wanttaja wrote:

Metal surfaces
want to be sprayed, and white paint is probably easier to monitor for
consistency during the process (spotting thin areas, detecting sags, etc.).
Ron Wanttaja

I've painted several airplanes and vehicles and boats, and I
can tell you that white is harder to apply than darker colors. In a
paint booth, white reflects so much light that shadows disappear and
it gets easy to apply too much paint. A painter needs to be able to
see that the paint is beginning to flow out, and there's a narrow
range of proper paint thickness between orange peel and sagging. White
just overwhelms my eyes and makes it harder to judge.
I live in a place that has snow much of the year, and in the
mountains near here there's snow in some places year-round. Over the
years too many white airplanes have disappeared and been found long
after, when the snow's gone. I want a color that will stand out as
much as possible; airplanes are tiny things and anything that will
catch SAR's eyes helps. Of course, further snow will cover that, too.
Someone else said yellow was the only color for an airplane. I
agree. My Jodel is bright yellow. I just don't dare crash in a canola
field in June.

Dan

I recall that even a light color like yellow is something like over 30%
hotter than white.

What 30% means? Either 50 deg C becomes 65 deg C or 122 deg F becomes
159 deg F?

--
SPace-SHIP

"wp" wrote in message
...
I recall that even a light color like yellow is something like over 30%
hotter than white.

What 30% means? Either 50 deg C becomes 65 deg C or 122 deg F becomes
159 deg F?

As I recall (and that is all I can do, since I can't find the chart again)
the white temperature was compared to a black temperature, both in direct
sun. All of the other colors were compared to that.

Surely somone can remember seeing that study, anyone?
--
Jim in NC

On Sat, 3 Nov 2007 09:31:29 -0400, "Morgans"
wrote:


Fiberglass airplanes almost demand it. If they get too hot, the epoxy gets
hot, and gets weak. Very weak.



Some of the new Cirrus versions are not white.

"B A R R Y" wrote in message
...
On Sat, 3 Nov 2007 09:31:29 -0400, "Morgans"
wrote:


Fiberglass airplanes almost demand it. If they get too hot, the epoxy
gets
hot, and gets weak. Very weak.



Some of the new Cirrus versions are not white.

Are they cured in autoclaves?

Epoxy can be designed to stay stronger at higher temperatures, but
generally, they are then required to cure in autoclaves, with the high
temperature and pressure making the higher yield temperatures possible.
--
Jim in NC