A Study in Confirmation Bias
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A Study In Confirmation Bias.
Starting with flight path is not preferred. Starting with aircraft and systems is preferred, logs, written notes, eyewitness data.
Flight path as origination of study is not broad enough. What follows is ‘tracking back’, a path that will offer dozens of false trails. It can also lead to bias, as it also fosters a “too early” formation of thesis. The tendency here is to look for confirmation. (Instead of other possibilities)
The AP was found to be “energized”, (ON). The switch was not known to have been guarded, and CAB claim no other means was available To the pilot to provide power to this system.
In pre take off, does the checklist say “CHECK AP OFF”. Or, does it say “Cycle the AP switch, Check AP OFF”
CAB claim by inference that the AP had nothing to do with the accident. Was there any possibility of the AP being (selected) “ON” at takeoff? They state it is unknown whether the AP switch was guarded. (This should be listed in maintenance, relative to “re-install”)
Why was the unit installed in the aircraft? Placarded INOP, why not leave it back at the avionics shop to be repaired?
Possibility:
1. No blank was available to seal the panel shut.
2. As part of the control system, some wiring in the AP was necessary to be present, hard wired to provide continuity for other circuits.
3. Records of AP maintenance? What was the problem?
4. Which channel was inop?
5. Was it the Switch that was the problem?
6. Was the switch powered?
Unfortunately, some one present put the story together within hours, prior to any testing of other potential theses. Also offered without ANY evidence.
Last edited by Concours77; 6th Jan 2018 at 15:55.