I only fly at night......
:-)
Gert
http://home19.inet.tele.dk/dalgaard/oygds.jpg
Den 23/07/2007 kl. 20.02 skrev Raimo Toivio:
> Hi Rob
>
> As I wrote
>
> "I am not going to encourage anybody to paint their
> Europa=B4s undersides any colour but white. I still well
>
> remember Manual=B4s words: all the Europas must be white."
>
>
> and
>
>
> "I think - with other colour as white - it is better to be even
> more careful. "
>
>
> and
>
>
> "Keep your full matt black Europa in the hangar and fly only night
> time if
>
> you wanna be absolutely sure"
>
>
> Anyway - I called to my friend Jukka Paavolainen, who has build
>
> and still flies his Lancair 320 OH-XJP. He said his Lancair is
>
> just on ordinary glasfibre - epox system and definetely not baked
>
> in high temparatures. Only the cowlings - because of the engine and
>
> exhaust heat - has been made by more heat resistant phenolresins.
>
>
> His Lancair kit is year model 1990 and so is my earlier example SE-
> XOP,
>
> which is overall deepred and beautiful Swedish Lancair 320.
>
>
> I believe newer models are as you described made by adanced
> composite materials.
>
>
> You wrote
>
>
> " Park on a black surface and the solar energy absorbed by that
> surface will be re-radiated to the underside of the aircraft, and
> if that aircraft is any color but white it will absorb too much
> energy. "
>
>
> and I still think you are wrong. I am going to talk to one
> thermodynamist,
>
> who works as a doctor in Tampere Univercity. Maybe he can make this
>
> thing clear. I promise to come back and tell what he know. Also if
> I am wrong...
>
>
> Fly it - do not melt it...
>
> Raimo
>
> ----- Original Message -----
> From: Rob Housman
> To: europa-list@matronics.com
> Sent: Friday, July 20, 2007 6:02 PM
> Subject: RE: Europa-List: Europa colours
>
> Sorry Raimo, but this is dangerous thinking for those of us flying
> in warmer climes.
>
>
> In my previous post I deliberately avoided getting into too much
> technical detail, and I used the word =93reflected=94 where I should
> have used the technically correct term =93emitted.=94
>
>
> First, you seem to misunderstand heat transfer. You are correct
> that the sun=92s energy is not reflected from a black surface.
> However, a =93black body=94 is not only a perfect absorber but also a
> perfect emitter, which is to say it may not be reflecting solar
> heating but it surely emits it. Park on a black surface and the
> solar energy absorbed by that surface will be re-radiated to the
> underside of the aircraft, and if that aircraft is any color but
> white it will absorb too much energy. Any material absorbing
> energy will increase in temperature. Sure, there will be some re-
> radiation from the dark aircraft structure but that is irrelevant
> because the epoxy-fiberglass will already have softened.
>
>
> Second, the Lancair aircraft all use a different composite than
> Europa. Here=92s how Lancair describes their composites on their web
> sitehttp://www.lancair.com/Main/legacy.html ---
>
>
> =93Like every Lancair, the Legacy=92s major airframe is constructed of
> advanced composite materials. Cured at 270 degrees Fahrenheit under
> vacuum pressure, these NASA tested, epoxy based composites are
> among the lightest, strongest, stiffest materials known.
>
>
> The high-temperature, pre-impregnated carbon fiber and/or
> fiberglass systems combined with Nomex/honeycomb core materials are
> considered the supreme composite airframe materials of choice
> worldwide.=94
>
>
> Note that the Lancair=92s composites are cured at a much higher
> temperature than the factory and we cure the Europa structural
> components. The =93glass transition temperature=94 is approximately
> the cure temperature so softening of the composite does not begin
> until approximately T sub g is reached. For a detailed explanation
> to T sub g see http://en.wikipedia.org/wiki/
> Glass_transition_temperature For our purposes we can consider the
> glass transition temperature the softening temperature, above which
> the structure loses a significant portion of its strength.
>
>
> Anyone contemplating painting a Europa any color other than white
> (including yellow) should review the chart in the Builders Manual,
> Figure 1, Colour-Temperature Relationship, on page 36-1 of the
> Europa XS Tri-Gear Manual, Issue 1, dated 30 May 1998.
>
>
> Best regards,
>
>
> Rob Housman
>
> Irvine, California
>
> Europa XS Tri-Gear
>
> S/N A070
>
> Airframe complete
>
>
> From: owner-europa-list-server@matronics.com [mailto:owner-europa-
> list-server@matronics.com] On Behalf Of Raimo Toivio
> Sent: Friday, July 20, 2007 1:28 AM
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Europa colours
>
>
> Rob,
>
>
> I am not going to encourage anybody to paint their
>
> Europa=B4s undersides any colour but white. I still well
>
> remember Manual=B4s words: all the Europas must be white.
>
>
> I still have to point out the energy of the sun is NOT
>
> reflecting out of the black asphalt IMHO. That is why
>
> it is hot when a sunny day. It absorbs allmost all the heat
>
> energy and nothing is reflecting out. White surfaces are
>
> cool because they are reflecting out much more.
>
>
> So it could be more dangerous to keep it on the snow covered
>
> surface while a sunny day (or on white sand or water w Europa
> floats!).
>
>
> In Sweden there has been 10 years a wonderful full colour mid red
> Lancair 320
>
> and no composite problems at all. Register # is SE-XOP (!). And like
>
> we all know in South America (Columbia?) there is flying a total
> deep yellow Europa.
>
>
> I think - with other colour as white - it is better to be even more
> careful.
>
> Beauty is a good reason for some extra work and some sacrifice.
>
> That is the fact all the women know. That is all.
>
>
> "Keep your full matt black Europa in the hangar and fly only night
> time if you wanna be absolutely sure"
>
>
> Raimo
>
> ----- Original Message -----
>
> From: Rob Housman
>
> To: europa-list@matronics.com
>
> Sent: Friday, July 20, 2007 2:32 AM
>
> Subject: RE: Europa-List: Europa rules
>
>
> Mike '
>
>
> In re: dark paint
>
>
> Don=92t even think about it. Where we live and fly, on warm days the
> heat reflected off the ramp will be sufficient to soften the epoxy-
> fiberglass enough to reduce the strength of the structure. Sure it
> will be OK at altitude but you still have to climb away from the
> surface. Folks flying closer to the Arctic Circle don=92t have to
> worry about getting the airframe too hot.
>
>
> Best regards,
>
>
> Rob Housman
>
> Irvine, California
>
> Europa XS Tri-Gear
>
> S/N A070
>
> Airframe complete
>
>
> From: owner-europa-list-server@matronics.com [mailto:owner-europa-
> list-server@matronics.com] On Behalf Of DuaneFamly@aol.com
> Sent: Thursday, July 19, 2007 3:23 PM
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Europa rules
>
>
> Raimo,
>
>
> Congratulations to you and your aircraft. I think we can all stand
> a little taller and more proud when one of "our" planes tops the
> list of all in an entire country.
>
>
> Do you have any pix of you panel? Is the underside of your aircraft
> really painted dark? Black, blue, brown? Any reasoning for this?
>
>
> Mike Duane A207A
> Redding, California
> XS Conventional Gear
> Jabiru 3300
> Sensenich R64Z N
> Ground Adjustable Prop
>
>
> http://www.matronics.com/Navigator?Europa-List
> http://forums.matronics.com
>
>
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