In-flight upset - 154 km west of Learmonth, WA, 7 October 2008,

Table 13: Troubleshooting data relating to the ADIRUsUnitsADIRUconnectionsResultsFCPC 1,FCPC 2,FCPC 3FMGEC 1,FMGEC 2ADIRU 2,ADIRU 3All 3 ADIRUsAll 3 ADIRUsAll 3 ADIRUsAt 0440, problem detected with ADIRU 1 data (IR andADR). Subsequent problems also detected.No problems with ADIRU 2 or ADIRU 3 data.At 0440, problem detected with ADIRU 1 data.No problems with ADIRU 2 or ADIRU 3 data.At 0440, problem detected with altitude and/or trueairspeed data not being received from ADIRU 1 at thedesigned rate (section 1.12.6).No problems with ADIRU 2 or ADIRU 3 data.GPWS ADIRU 1 At 0440, problem detected with ADIRU 1 data.LGCIU 1,LGCIU 2ADR1 and ADR 3At 0531, problem detected with loss of computedairspeed from ADR 1.No problems with ADR 3 data.1.12.4 Functional testing of aircraft systemsAfter the PFR and TSD data were downloaded, functional tests were performed onseveral aircraft systems at Learmonth in accordance with the aircraft manufacturer'srecommendations. The systems included the EFCS, ADIRS, FMGES, PHCs, multimodereceivers (which included the GPS receivers), and the electrical powergeneration system.All of the functional tests were successfully completed except for a single EFCStask that involved the reconfiguration of the elevator servo-controller to anothercomputer. The aircraft manufacturer advised that this was a previously identifiedanomaly that was only triggered under a very specific set of circumstances and wasnot related to the occurrence. 601.12.5 Aircraft wiring examinationsThe data-spike failure mode affected data that was transmitted on multiple,segregated wires out of the ADIRU (and based on information obtained frommultiple, segregated wires into the ADIRU). A simultaneous problem with multiple,segregated wires was considered very unlikely.Nevertheless, a range of testing was conducted on the aircraft wiring, and noproblems were found. More specifically:• Due to the extent of damage to the ceiling panels in the cabin, all the panelswere removed and the wiring looms were visually inspected while the aircraftwas at Learmonth. No defects were observed.• After the aircraft was ferried to a maintenance base in Sydney, the operatorconducted precautionary checks of the aircraft’s ADIRU interface wiring that60The anomaly only occurred during the performance of functional tests. It appeared with theintroduction of a particular FCSC software version.- 50 -