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Old December 10th 07, 03:18 PM posted to rec.aviation.owning
Jay Honeck
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Posts: 3,573
Default JPI Engine Data Analysis Questions

What I have started doing is looking at average, peak-to-peak variation, and
standard deviation on each channel, over a half-hour or so of stable cruise.
I am watching for any trend or sudden change in variability of data on a
channel. Doesn't tell all, but I hope it will alert me to something going
awry, whether it is engine or sensor. And it was easy to do in Excel.


In another forum a guy mentioned that you want to look for
fluctuations up and down in EGT, as it is an early indicator of a
sticky valve.

The question, of course, is what's a "normal" fluctuation, and what's
"abnormal"... Looking at my data most cylinders go up and down 10 to
15 degrees pretty regularly...

I'm assuming that's "normal" because they're all doing it -- but it
would be good to see some hard data on what these lines actually mean.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"