Why are airplanes white?

In a previous article, "Bob Gardner" said:
It gives the manufacturer more options in selecting trim colors, just as all
Boeing jets come out of the factory green.

I thought Boeing jets come out of the factory covered in Zinc Chromate
rather than paint?

--
Paul Tomblin http://blog.xcski.com/
Beware of bugs in the above code; I have only proved it correct, not tried it.
- Donald Knuth

Your assumption is that solar heating is a factor. If the aerodynamic
heating is high, one could argue radiative heat transfer would be
enhanced with black body radiation. The SR 71 is, you might notice,
black, but that may be the result of long wavelength (longer than
optical at least) absorbance considrations.

On Nov 3, 1:41 pm, Mxsmanic wrote:
Jay Honeck writes:
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?

Actually it does, at least for high-speed aircraft. They are already heated
externally by aerodynamic friction, and letting the sun beat down on them at
high altitude with a black paint job would only heat them up more.

However, some black liveries are in service, so apparently it's not enough to
cause a problem. The old Playboy corporate jet was entirely black, and I
think there have been a few others.

For small GA aircraft, I can't think of any obvious reason why they should be
painted white.

On 3 Nov, 19:04, Tony wrote:
Your assumption is that solar heating is a factor. If the aerodynamic
heating is high, one could argue radiative heat transfer would be
enhanced with black body radiation. The SR 71 is, you might notice,
black, but that may be the result of long wavelength (longer than
optical at least) absorbance considrations.

On Nov 3, 1:41 pm, Mxsmanic wrote:



Jay Honeck writes:
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?

Actually it does, at least for high-speed aircraft. They are already heated
externally by aerodynamic friction, and letting the sun beat down on them at
high altitude with a black paint job would only heat them up more.

However, some black liveries are in service, so apparently it's not enough to
cause a problem. The old Playboy corporate jet was entirely black, and I
think there have been a few others.

For small GA aircraft, I can't think of any obvious reason why they should be
painted white.- Hide quoted text -

- Show quoted text -

Loads of good stuff already; I am pretty sure that
white shows up surface defects less redily than
other colours and that black shows them most
clearly. Anyone in car painting would know this for sure.

I did read recently that the SR-71 was black to
reduce the surface temperature by increasing
radiation away from the aircraft. Clearly aeordynamic
heating of the structure put a lot of energy in.

"Richard Riley" wrote

http://tinyurl.com/yv62an
http://tinyurl.com/yu2jnu

That one is close, though there was a clearer, easy to interpret study, I
think.
--
Jim in NC

I just hope this conversation doesn't give them the Green light to start
profiteering from the aviation industry.

We can talk until we're blue in the face, but it'll remain a black
comedy until Sharpton (whatta marroon!) sees this golden opportunity
to get back in the pink with his followers, and shows signs of seeing
the many shades of gray that this topic has to offer.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

I did read recently that the SR-71 was black to
reduce the surface temperature by increasing
radiation away from the aircraft.

???

I thought black increased surface temperature?
--
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?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"


http://www.soaridaho.com/Schreder/Co...olor_Temp.html

JS

No Jay, black is more absorbant and more emissive than a shiny
surface. If it's sun light heating you're trying to reduce, you'd want
to reflect away the energy with a reflective surface. If, though, the
thing you're worried about is hotter than its surroundings and you are
interested in radiating the heat away, you'd want increased
emissivity, and make it black. A black body radiater is considered
perfect, and it is very black indeed.


On Nov 3, 5:22 pm, Jay Honeck wrote:
I did read recently that the SR-71 was black to
reduce the surface temperature by increasing
radiation away from the aircraft.
silverf sur
???

I thought black increased surface temperature?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993www.AlexisParkInn.com
"Your Aviation Destination"

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.

In article ,
(Paul Tomblin) wrote:

In a previous article, "Bob Gardner" said:
It gives the manufacturer more options in selecting trim colors, just as all
Boeing jets come out of the factory green.

I thought Boeing jets come out of the factory covered in Zinc Chromate
rather than paint?

I thought Zinc Chromate is green. At least the Zinc Chromate I have is green.

--
Bob Noel
(goodness, please trim replies!!!)