Old 29th Dec 2018, 12:50
  #44 (permalink)  
Join Date: Jul 2014
Location: Germany
Posts: 339
Originally Posted by DaveReidUK View Post
Are you sure about that ?

I haven't seen any FDR traces for the two flights where problems were reported that occurred prior to the AoA sensor replacement. Nor AFAIK has there been any report on the condition of the removed sensor.

IMHO it's entirely possible that neither sensor was faulty and both were correctly installed, i.e. the fault was farther downstream and replacing the sensor made no difference.
No i'm not sure. I'm reading between the lines.
On the preliminary report on pages 7, 8 and 9 the maintenance log is described.
(Preliminary Report: http://jacdec.de/database/2018-10-29...y%20Report.pdf)

Before changing the AoA sensor the main symptom is:
Speed and Altitude Flag show on Captain Primary Flight Display (no speed and altitude indication)
Only after changing the AoA sensor the IAS disagree behaviour started:
IAS and ALT Disagree shown after take off
Also i'm quite certain if the wrong AoA with stick shaker activation would have been present prior to the Denpasar-Jakarta leg it would have been mentioned in the report.

Could also be maintenance screwed up the SMYD1 somehow i don't know. But it seems certain the really dangerous fault was introduced with that maintenance option.

Of course the report could have left out that the other flights had an AoA disagree as well but somehow i doubt that. Also yes the maintenance log could be wrong, but no speed indication vs airspeed disagree indication, i trust them to get at least that much right. Especially because there were multiple occasions of that problem.
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