A Bombardier Q400 displays error code 938 on the Central Diagnostics System(CDS), which is attributed to turbomachinery chip detector. An examination shows debris in the detector hitch which is collected and sent for further analysis.

Meanwhile, while on a flight the crew experiences an automatic engine shutdown with the following codes and their corresponding explanations showing on the CDS:

  • 732-NH Speed Sensing (Connectors Eng. controls Harness NH sensor A EEC (Freq In))
  • 907- Engine Flameout
  • 915-Replace Main Oil Filter
  • 938-Turbo-machinery Chip Detected

Has anyone experienced similar problems or have any lead on the same?

  • $\begingroup$ No clue but if you don't get an answer and eventually figure it out, please do post an answer :) $\endgroup$ – ymb1 Mar 27 '18 at 13:28
  • $\begingroup$ Sounds like there was debris found in the engine oil. That's the typical case that a "chip detector" is looking for, and would cause the need to replace the oil filter. How that relates (cause vs effect) to the first two items, would require somebody with more experience on that aircraft than I have. $\endgroup$ – Ralph J Mar 27 '18 at 18:59
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    $\begingroup$ This sounds like a service request to Bombardier might be a good approach... $\endgroup$ – Cpt Reynolds Mar 27 '18 at 20:14

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