Message text written by INTERNET:europa@avnet.co.uk
>Has anyone a tabulation or data that compares Outside Air Temperature
versus
Skin Temperature of a white aircraft? I understand that we can easily
accomodate an OAT of 25-30 Degrees Celsius in our White Plastic Aircraft,
but can we take 35-40 Degrees Celsius??
In anticipation, thanks
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=92s. 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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