Hi Bob,
Thanks for the report. The overheat shut down of iPads has been
known and reported since the release of these products years ago.
Heat accelerates the deterioration of all electronic components
under all circumstances, although some components are a bit more
tolerant than others. Ambient temperature is irrelevant from an
engineering perspective. Apple's Guidelines are written by lawyers for
consumers who might sue for melting their iPhone by leaving it on an
automobile glare shield on a sunny day in Las Vegas.
The actual technical detail is that these devices have an internal
temperature sensor which activates a shut down process at a CPU
temperature of 145F if memory serves (and these days it may not).
If you arrange for convective or forced air cooling of the device in your
cockpit, the ambient temperature is much less important.
The Garmin products you mentioned were designed for use in hot
cockpits and also for use in bright sunlight. The Apple products
were designed for light weight, long battery life, and convenient form
factor for their intended purpose.
Life is a tradeoff and many people use iPads, etc. in flight because the
software is arguably much better (easier to use, more features, etc) and
the software vendors like Foreflight charge much less for database updates
than the bloodsucking Garmin or Jeppesen. Life is a tradeoff.
Also, allow me to correct a misperception. Running Foreflight (for example)
does not make an iPad (or any computer running an application) work
"harder". The machine is running the same CPU clock if running your app or
sitting in an idle loop. In the case of iPads and iPhones, the rapid updating
of
GPS position does slightly increase battery draw, but this can be more than
compensated for by shutting off the baseband functions (i.e., the cell phone
functions in flight) which draw far more power than the GPS. The most
power consumption in one of these products is usually the backlight behind
the LCD screen. In a bright cockpit like a Europa, you would almost certainly
set the screen brightness to maximum, whereas in a Cessna, the screen
would be readable with far less brightness.
Ira
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Ira N224XS
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