**Appendix C**

**Level 1 Level 2** Maintenance Control Work orders not carried out Mismatch between logs/work order and work carried out/actual configuration Scheduled tasks overdue Mismatch between MX forecast and actual times/cycles Action not signed off AD not embodied/not in compliance on a/c Action sign off/explanation incorrect or unclear Instructions/limitations to other team/shift/department not communicated/unclear/incorrect Additional inspections not planned/carried out Defect deferred with incorrect procedure/reference/follow-up Work orders/task not in planning, or planned with incorrect interval Authorisation does not cover work carried out/authorisation issued Maintenance documentation Instructions or references incorrect/unclear Incorrect or incomplete documentation present/used Parts supply/tracking/life limits Incorrect part supplied Parts supplied with incomplete/incorrect repair, modification, configuration or condition. Parts supplied with FOD/damage/corrosion present Parts supplied with incorrect/incompatible life remaining Mismatch between parts installed and tracking system Incorrect life recorded in tracking system Time expired parts (found to be) fitted Uncertainty about part documentation Tool issue Incorrect tool used/available Tools used had incorrect calibration status Job access/job set-up issue Incomplete/incorrect job set up Damage caused by access equipment Damage caused by lifting equipment/special tools Working practices Created opportunity for damage/contamination/FOD Accumulation of dirt/fluids/grease/water/other contamination present Damage present, or damage caused by work carried out Incorrect procedure used or procedure applied incorrectly Troubleshooting issues Results incorrect Results unclear Previous troubleshooting did not clear the issue Lubrication/servicing issue Lubrication not (correctly) carried out Wrong type lubricant used Lubrication overdue Servicing not (correctly) carried out Refill task incomplete/incorrect Servicing overdue Inspection/testing issue Inspection or test not carried out or not complete Inspection or test carried out incorrectly Inspection or test results not carried forward Inspection or test did not identify an existing issue Installation/removal issue Clearance issue Part missing Part incorrect Part unserviceable Installation/removal incomplete Damage present, caused by installation/removal Installation/removal incorrect Wrong (consumable) material used Wrong fastener used Wrong software version loaded or wrong config/setup Incorrect/incompletefollow-upafterinstallation/removal

**Table A3.** Hieminga (2018) Maintenance error Taxonomy.


**Table A3.** *Cont*.
