On 8 Dec 2006 18:39:30 -0500, "Ash Wyllie" wrote:

Mxsmanic opined

writes:

On a clear night the skin temperature can go BELOW the air
temperature due to the radiation losses into space.

The temperature of the aircraft won't drop below the temperature of
the ambient air, as long as the aircraft is dry.

Actually, it can. I have seen frost on metal surfaces (like wings) when the air
temp is above freezing. Taxiing will sometimes melt frost.

As usual, mxsmanic is both right and wrong (as in 'a little knowledge can be
a dfangerous thing"). When the skin radiates, it cools down, and will cool
the air in contact with its surface. This creates a thin inversion layer,
which (in the absence of any appreciable wind) is stable. The air
temperateure a few millimeters above the skin will be significantly warmer.


A clear night sky is /cold./


-ash
Cthulhu in 2005!
Why wait for nature?