risk in the maintenance environment
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
EMSG Conference 10 October 2007AAIB 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 2007AAIB Farnborough
EMSG Conference 10 October 2007AAIB Farnborough
PRESENTATION OVERVIEW
SAFETY SYSTEMS AND HUMAN PERFORMANCE
MAINTENANCE ERROR AND BUSINESS RISK
REMEDIAL MEASURES
EMSG Conference 10 October 2007AAIB 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 2007AAIB Farnborough
SAFETYMANAGEMENT SYSTEMS
SAFETY SYSTEMS AND HUMAN PERFORMANCE
IN MAINTENANCE
EMSG Conference 10 October 2007AAIB 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 2007AAIB Farnborough
ERROR TYPE MAINTENANCE EXPERT DATA
ASSESSMENT
Skip a step 0.15 0.001Skip a task 0.026 0.001Ignore a warning/caution 0.042 0.013Intentionally deviate 0.042 0.32Improperly remove/replace 0.033 0.02Improperly repair 0.089 0.0023Incomplete installation 0.089 0.01Improperly adjust 0.09 0.1Allow/cause debris to enter 0.17 0.01
SAFETY SYSTEMS AND HUMAN PERFORMANCE
IN MAINTENANCE
Source Ostrom et al, INEEL
EMSG Conference 10 October 2007AAIB Farnborough
PROCEDURES MITIGATE RISK OF HUMAN ERROR
Clear documentationParts kitsChecklistsInspections Function checks
Even pre-flight checks
SAFETY SYSTEMS AND HUMAN PERFORMANCE
IN MAINTENANCE
EMSG Conference 10 October 2007AAIB 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 2007AAIB Farnborough
Can your maintenance staff actually perform the required inspections?
EMSG Conference 10 October 2007AAIB Farnborough
Do you have uncontrolled small parts?
EMSG Conference 10 October 2007AAIB Farnborough
Do your engineers improvise?
EMSG Conference 10 October 2007AAIB Farnborough
Are your engineers under pressure to avoid ground runs at night?
EMSG Conference 10 October 2007AAIB Farnborough
Do your engineers sign off task cards sight unseen?
EMSG Conference 10 October 2007AAIB Farnborough
Is the Approved Data correct and is there a viable procedure to amend errors?
EMSG Conference 10 October 2007AAIB Farnborough
MAINTENANCE ERROR AND BUSINESS RISK
EMSG Conference 10 October 2007AAIB Farnborough
MAINTENANCE ERROR AND BUSINESS RISK
EMSG Conference 10 October 2007AAIB 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 2007AAIB Farnborough
MAINTENANCE ERROR AND BUSINESS RISK
EMSG Conference 10 October 2007AAIB Farnborough
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MAINTENANCE ERROR AND BUSINESS RISK
EMSG Conference 10 October 2007AAIB 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)
2 The risk of fines, litigation, denied insurance claims
EMSG Conference 10 October 2007AAIB Farnborough
THE COSTS OF A MAINTENANCE EVENT
Rework/re-instatement costsAdditional hangar time costsRepair costs for consequential damageMaintenance re-scheduling and knock-on delaysOperational schedule related costsCompensation costsCost of hiring a replacement aircraftBusiness costs –
obtaining and retaining market share
MAINTENANCE ERROR AND BUSINESS RISK
EMSG Conference 10 October 2007AAIB 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 2007AAIB 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 2007AAIB 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 2007AAIB Farnborough
THANK YOU FOR YOUR ATTENTION