Air data inertial reference unit: Difference between revisions

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==Complexity in redundancy==

Analysis of complex systems is itself so difficult as to be subject to errors in the certification process. Complex interactions between flight computers and ADIRU'sADIRUs can lead to counter-intuitive behaviour for the crew in the event of a failure. In the case of [[Qantas Flight 72]], the captain switched the source of IR data from ADIRU1 to ADIRU3 following a failure of ADIRU1; however ADIRU1 continued to supply ADR data to the captain's primary flight display. In addition, the master flight control computer (PRIM1) was switched from PRIM1 to PRIM2, then PRIM2 back to PRIM1, thereby creating a situation of uncertainty for the crew who did not know which redundant systems they were relying upon.<ref name="harmful">

{{cite web |url=http://www.dcs.gla.ac.uk/~johnson/papers/ISSC09/ADIRU_Accident_Submission.pdf |title=The Dangers of Interaction with Modular and Self-Healing Avionics Applications: Redundancy Considered Harmful |author1=C.W. Johnson |author2=C. Michael Holloway |date=2 February 2009 |access-date=8 June 2009}}</ref>