Herb,
Could you please give me the details of the manufacturer of the AEW 24 of
yours so that I can contact them to try and get hold of one of these skin
temperature sensors. SP Systems Technical Division have quoted the following
temperature variations on white skinned aircraft. Quote 1:" If as you say
the ambient temperature is 45 Degrees this will give a surface temperature
of 75 Degrees on a white painted surface."
Quote 2 "I do not know if the Europa was designed with or without a postcure
so I can not comment if this is the case. But I would like to point out that
Ampreg 20 with slow hardener which is allowed to cure at room temperature
for 4 weeks has a HDT (Heat Distortion Temperature)of 51 Degrees, I have
referred to a graph which shows ambient air temperature against surface
temperature for different coloured surfaces. The "best" colour is white
which would allow you to have a air temperature of 24-25 Degrees. IF on the
other hand you give the laminate 16 hours at 50 Degrees this will give a HDT
of 71 Degrees from the same graph a white laminate would require a ambient
air temperature of approximately 40 Degrees to reach that temperature.
to a lesser degree Strength after Postcure, I now have a dossier of
correspondence with SP and have a good, helpful contact for queries.
Regards
Tony Renshaw
Builder No.236
>Tony,
>having flown fiberglass gliders for 17 years, I have not seen a flight
>manual (look under operating limitations) that explicitly states a max OAT
>for a white painted glider. Since we are flying from rather hot locations
>(here in the American West, you in central Australia), this is an important
>issue. The emphasis is on "white" since all other colors increase the
>surface snd structural temperatures substantially. On my ASW 24 I have red
>painted winglets and the surface temp. difference is around 10 deg. C vs
>the wing.
> Interestingly, for the Diamond Katana aircraft I rent occasionally
>(all-fiberglass construction with gel-coat surfaces) there are minimum and
>maximum temps for safe operation in the handbook. Min OAT is stated as
>-25C, or -13F and max OAT is 55C or 131F. There is a "Structural
>Temperature Indicator" in the aircraft that needs to be checked at
>temperatures higher than 38C or 100F. The indicator turns from red to
>black at 55 deg. C. Even in direct sunlight and high OAT's, a white
>aircraft will most likely not get that hot. I just read Martin Tuck's
>response and I doubt the values he is stating for white surfaces in 38C
>OAT's. Next time I go flying in plenty of heat and sunshine, I will take a
>digital thermometer along and take some readings.
>
>Don't mess with too much color, guys!
>Herb
>
>
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