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stevek999
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re: Tracking system loses crashed copter
stevek999   10/29/2010 9:13:20 AM
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this is a classic example of what i call the steve k theory of bugivity which states that if you spot your system doing something that it shouldnt be then it is probably also NOT doing something it should be

sbender130
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re: Tracking system loses crashed copter
sbender130   10/28/2010 3:27:26 PM
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This original story was oh- so familiar. The coincidence of an asynchronous interrupt event with the mixing/stirring of the background threads producing a "finger-in-the-fan-blades" scenario. You can get away with it for a while, but eventually the finger gets lopped off. Although this was a software bug and easily fixed once found, I've seen similar issues with hardware. Getting a chip vendor to believe you when "no one else is seeing this" is a problem.

Larry.Cormier1
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re: Tracking system loses crashed copter
Larry.Cormier1   10/28/2010 2:16:56 PM
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This is another instance of the #1 old adage of troubleshooting: Fix the obvious. Even though the printer error did not cause the failure, it was an indicator of the root cause. If this obvious error was fixed, the failure would not happen.

sharps_eng
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re: Tracking system loses crashed copter
sharps_eng   10/23/2010 7:51:21 AM
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@GJS - Ah, I see (thanks Wikipaedia:EPIRB). RF beacons don't give the resolution needed to get rescuers within shouting distance. OK.

sharps_eng
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re: Tracking system loses crashed copter
sharps_eng   10/23/2010 7:29:24 AM
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@GJS - wouldn't that be assuming that the IR beacon is still capable of transmitting? Though if I'm the guy in the wilderness I'd be grateful for any darn device to Tx/point/wave about - on any darn wavelength! :-) Someone actually has to be looking in your area, so is there something special about MWIR you can share? (Compared to a standard RF rescue beacon, that is.)

GJS
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re: Tracking system loses crashed copter
GJS   10/23/2010 3:31:10 AM
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Apart from a good hunt one other thing stands out. As my Grandmother used to say, "don't put all your eggs in one basket". An MWIR signalling device capable of being seen from a satellite would be fantastic for aircraft, ships and anyone going to “lonely places”. Better than EPIRB, as the bolometer on the rescue helicopters can see the beacon before the distressed craft is visible. :) Geoff Sherrington

WKetel
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re: Tracking system loses crashed copter
WKetel   10/23/2010 1:38:52 AM
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Expat is certainly correct on all points! Just because a bug is not seen to produce a catastrophic failure, it only means that the end user is not watching. Worse yet, it applies to hardware as well as software.

Expat Canuck
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re: Tracking system loses crashed copter
Expat Canuck   10/22/2010 6:06:32 PM
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This is an excellent article and it drives the point home that the symptom is not the bug and that the cause needs to be thoroughly investigated and resolved. I've seen rarely occurring bugs that were simply dismissed as "unrepeatable" and the product released to an unsuspecting customer, only to have it returned (under warranty) due to some other catastrophic manifestation. This is still a far too common occurrence.

brian hayes
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re: Tracking system loses crashed copter
brian hayes   10/22/2010 5:54:06 PM
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As a embedded systems programmer in those days, I can relate. I made tons of mistakes, usually fixed them before anybody noticed. I loved my work, but never held a professional job after 9/11.



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