EMSG Conference 10 October 2007 AAIB Farnborough RISK IN THE MAINTENANCE ENVIRONMENT ROYAL AERONAUTICAL SOCIETY ENGINEERING MAINTENANCE STANDING GROUP CONFERENCE AAIB FARNBOROUGH, 10 OCTOBER 2007 Alan P Simmons M.Sc., C.Eng., M.R.Ae.S. Principal Inspector of Air Accidents, Air Accidents Investigation Branch, United Kingdom

EMSG Conference 10 October 2007 AAIB Farnborough

EMSG Conference 10 October 2007 AAIB Farnborough PRESENTATION OVERVIEW SAFETY SYSTEMS AND HUMAN PERFORMANCE MAINTENANCE ERROR AND BUSINESS RISK REMEDIAL MEASURES

EMSG Conference 10 October 2007 AAIB Farnborough SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE Our safety systems have evolved: Checking/inspecting: Quality Control Controlling the production process: QC, TQM Managing safety: MEMS, SMS

EMSG Conference 10 October 2007 AAIB Farnborough SAFETY MANAGEMENT SYSTEMS SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE

EMSG Conference 10 October 2007 AAIB Farnborough LIMITATIONS OF HUMAN PERFORMANCE Perception and Cognitive limitations Optical and Auditory limitations Tunnelling and focusing SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE Man errs as long as he strives. Goethe

EMSG Conference 10 October 2007 AAIB Farnborough ERROR TYPEMAINTENANCEEXPERT DATAASSESSMENT Skip a step Skip a task Ignore a warning/caution Intentionally deviate Improperly remove/replace Improperly repair Incomplete installation Improperly adjust Allow/cause debris to enter SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE Source Ostrom et al, INEEL

EMSG Conference 10 October 2007 AAIB Farnborough PROCEDURES MITIGATE RISK OF HUMAN ERROR Clear documentation Parts kits Checklists Inspections Function checks Even pre-flight checks SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE

EMSG Conference 10 October 2007 AAIB Farnborough WHY PROCEDURAL ERRORS UNDERMINE SAFETY: Clear documentation is useless if not used Parts control cannot work if uncontrolled stocks are held Independent Inspections must be truly independent Function checks must be carried out SAFETY SYSTEMS AND HUMAN PERFORMANCE IN MAINTENANCE

EMSG Conference 10 October 2007 AAIB Farnborough Can your maintenance staff actually perform the required inspections?

EMSG Conference 10 October 2007 AAIB Farnborough Do you have uncontrolled small parts?

EMSG Conference 10 October 2007 AAIB Farnborough Do your engineers improvise?

EMSG Conference 10 October 2007 AAIB Farnborough Are your engineers under pressure to avoid ground runs at night?

EMSG Conference 10 October 2007 AAIB Farnborough Do your engineers sign off task cards sight unseen?

EMSG Conference 10 October 2007 AAIB Farnborough Is the Approved Data correct and is there a viable procedure to amend errors?

EMSG Conference 10 October 2007 AAIB Farnborough MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough Most maintenance error events investigated by AAIB are INCIDENTS not ACCIDENTS Maintenance related incidents form a larger proportion of total maintenance related events investigated by AAIB than accidents Incidents are less spectacular but very expensive MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough … MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough MAINTENANCE ERROR AND BUSINESS RISK Procedural deviations are at the root of many maintenance related events Maintenance error arising from non-procedural practices incurs a dual risk to the business: 1 The risk of exposure to loss (loss of safety,earnings) 2The risk of fines, litigation, denied insurance claims

EMSG Conference 10 October 2007 AAIB Farnborough THE COSTS OF A MAINTENANCE EVENT Rework/re-instatement costs Additional hangar time costs Repair costs for consequential damage Maintenance re-scheduling and knock-on delays Operational schedule related costs Compensation costs Cost of hiring a replacement aircraft Business costs – obtaining and retaining market share MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough Recent examples from AAIB investigations into actual incidents: A technician assembled propeller de-icer boots without the required sealant materials, which were difficult to obtain. The boot detached causing injury and damage. A mechanic assembled a helicopter rotor head without the required shims, because the job was urgent. The helicopter suffered severe vibration and blade cracking. After major maintenance, an engineer stamped up a number of job cards to close all remaining open panels, but not all the panels were open at the time. One of the closed panels was not properly closed and latched. The panel came off and penetrated the cabin.

EMSG Conference 10 October 2007 AAIB Farnborough How can we reduce the risk of maintenance error? By promoting: A culture which rewards procedural compliance… …and discourages violations Error-tolerant systems Reporting systems which work and are used An analytical approach to risk MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough In 1994 AAIB stated: ‘The Civil Aviation Authority should formally remind engineers of their responsibility to ensure that all work is carried out using the correct tooling and procedures, and that they are not at liberty to deviate from the Maintenance Manual but must use all available channels to consult with a design authority where problems arise; if full compliance cannot be achieved the engineer is not empowered to certify the work’. [Airbus A320, G-KMAM AAIB Report 2/95, Safety Recommendation 94-41] This is still the only way forward. MAINTENANCE ERROR AND BUSINESS RISK

EMSG Conference 10 October 2007 AAIB Farnborough THANK YOU FOR YOUR ATTENTION