Human Factor

      Social Psychology  is the  scientific  study of how people's  thoughts ,  feelings ,and  behaviors  are influenced by the actual, imagined, or implied presence of others.                Social psychologists examine factors that cause behaviors to unfold in a given way in the presence of others.      Social psychologists  study conditions under which certain behavior, actions, and feelings occur. Social psychology is concerned with the way these feelings, thoughts, beliefs, intentions, and goals are cognitively constructed and how these mental representations, in turn, influence our interactions with others.       Social Environment -  AMEs work within a “system”.  There are various factors within this system that impinge on the AMEs , ranging from his knowledge, skills and abilities , the environment in which he works, to the culture  of ...

 Internal Occurrence Management Scheme (OMS).  An Occurrence Management Scheme should contain the following elements:   clearly identified aims and objectives;  demonstrable corporate commitment with responsibilities for the Occurrence Management Scheme clearly defined;   corporate encouragement of uninhibited reporting and participation by individuals;   disciplinary policies and boundaries identified and published;  an occurrence investigation process;   the events that will trigger error investigations identified and published;  investigators selected and trained;  OMS education for staff, and training where necessary;   appropriate action based on investigation findings• feedback of results to workforce;   analysis of the collective data showing contributing factor trends and frequencies.                        The aim of the scheme i...

               A key element of a HFP is a system whereby problems, or potential problems, can be reported and dealt with.                                           Many organisations already have some form of reporting system for technical issues or discrepancies, but this may need to be expanded, or additional system(s) put in place, to allow for the reporting of human errors, ambiguities with procedures, mismatches between required and actual practice, etc.              The CAR145 requirement is for an organisation to have in place an internal occurrence reporting scheme to enable the collation of occurrence reports, including the assessment and extraction of relevant information in order to identify adverse trends or to address deficiencies in the interests of safety.         ...

   What is most important is to emphasise the combined responsibility of the organisation, its management and supervisors, its processes and procedures, as well as the individual responsibility of each employee (not just certifying engineers) towards safety. Everyone has their own idea of what constitutes "professional" behaviour. Human factors training, and a company human factors programme can help set and maintain standards for professional behaviour, and provide staff with the mechanisms and support to enable them to work professionally. The problem might be that although staff know full well what they ought to be doing in keeping with professional standards, they are prevented from behaving as they would wish by organisational problems (e.g. poor procedures, commercial pressures, unavailability of correct tooling, poor training, etc.).          When the subject of professionalism is addressed in a company human factors training course, it is up to...

  This chapter will not go into details concerning management styles and techniques, nor the theories of leadership and followership - these are all covered more than adequately in various management texts, and also in James Taylor's book "Maintenance Resource Management". Instead, it stresses the importance of getting people at management and supervisory level to understand what the human factors programme is all about, and on getting 'buy-in' at senior management level. Top level management support is crucial to the success of a company human factors and error management programme. It is also particularly important to get middle management and supervisors on-board for the programme to be successful, and for them to demonstrate commitment to the programme to the staff. Supervisors are particularly important in the success or failure of a human factors programme, since it is they who set the standards which others are likely to follow. If, for instance, a supervi...

   Planning is critical to human factors in that it should aim to ensure that there are adequate appropriately qualified and alert personnel, tools, equipment, material, maintenance data and facilities at the right place, at the right time, for the scheduled and unscheduled tasks.        CAR 145 states that an organisation may only maintain an aircraft /component when all necessary facilities, equipment, tooling, material, maintenance data and certifying staff are available.  It is not the purpose  to tell planners how to do their jobs but, rather, to highlight some of the human factors issues which they should be taking into account in the planning process, such as human performance limitations when working shifts and long hours.                                                 Depending on the amount and complexity of work ...

  Research indicates that many maintenance tasks are signed off unseen. In order to prevent omissions, mis-installations, etc., every maintenance task or group of tasks should be signed-off. To ensure the task or group of tasks is completed, sign-off should only take place after completion and appropriate checks.          Work by noncompetent personnel (i.e. temporary staff, trainee, etc.) should be checked by authorised personnel before they sign-off. The grouping of tasks for the purpose of signing-off should allow critical steps to be clearly identified.       NOTE: A “sign-off” is a statement by the competent person performing or supervising the work, that the task or group of tasks has been correctly performed. A sign-off relates to one step in the maintenance process and is therefore different to the release to service of the aircraft.  Signing off small groups of tasks will help prevent situations where a technician is called awa...

   The primary objective of handovers is to ensure that all necessary information is communicated between the out-going and in-coming personnel. Effective task and shift handover depends on three basic elements:  • The outgoing person’s ability to understand and communicate the important elements of the job or task being passed over to the incoming person.  • The incoming person’s ability to understand and assimilate the information being provided by the outgoing person.  • A formalised process for exchanging information between outgoing and incoming persons and a place and time for such exchanges to take place.  Organisations should have a recognised procedure for task and shift handovers which all staff understand and adhere to. This procedure should be listed in the MOE.   Ideally the procedure should provide for sufficient time to be made available by way of a shift overlap, depending on the complexity of task(s) to be handed over. As a guidel...

 Reporting Discrepancies               In addition to an occurrence reporting system, where a problem has resulted in some soft of event, there should be an internal occurrence/discrepancy reporting system whereby staff can report inaccuracies or ambiguities in procedures, or, indeed, suggest better ways of doing particular tasks, such that procedures can be frequently updated and improved. This system must result in actions and improvements to the procedures, otherwise it will not be used by the workforce.        There is plenty of scope within AMO to provide consistency in its documentation. Indeed, Part-145 requires organisations to provide a common workcard or worksheet system for use throughout relevant parts of the organisation.           Access The best designed procedures are of little use unless they can be accessed and used by the engineers and technicians in real working environment...

       A work instruction is what you should do, whereas a procedure is how you should do it.        Job cards are usually work instructions; procedures generally originate from the Maintenance Manual.        Writing Procedures and Work Instructions As well as maintenance data and procedures provided by the manufacturer having scope for improvement, there is also often a better way of writing or presenting technical procedures and work instructions which are produced by, and used within, a maintenance organisation.                                                                   Obviously the fundamental elements of the procedures should not deviate from the manufacturer’s requirement, but there is often scope for presenting that information in such a way that...

       It is recognised that some maintenance manuals provided by the manufacturers often offer scope for improvement.                                     Ideally, maintenance manuals should be validated when first written, for each new aircraft type and variant, but this is a task which is rarely carried out as thoroughly as it might be, if at all.                                                              Accordingly, it tends to be left to operational experience to pick up the inaccuracies, ambiguities or missing information in maintenance manuals.                           In addition, the information in the maintenance manual is not necessarily a...

 There has been a great deal of research carried out in North America1 concerning environmental factors such as temperature, noise, lighting, etc. and a detailed Ergonomic Audit tool (ERNAP2) developed appropriate for aviation maintenance, which can assist in the evaluation of work environments, tooling and documentation. Further details may be found in Appendix Q. The Safety Health of Maintenance Engineering (SHoMe) tool (Appendix M) also looks at aspects associated with the working environment and tooling, although not in any great detail. It is appreciated that aircraft maintenance takes place in many different locations and environments, and that it is not always possible to carry out maintenance in a hangar maintained at a comfortable temperature, with adequate lighting and noise levels, etc. However, it should be recognised that environmental factors can contribute towards errors and efforts made to ensure that the environment is as ‘work-friendly’ as reasonably possible, e.g...

           Duplicate Inspections are inspections where the task or process is performed by one person, a first check carried out by that person (if qualified to self-certify) or by a supervising certifying engineer, and then independent checks carried out by a second suitably qualified person. Both the first and second checks should be thorough and, in the case of control systems, ensure that they include functional checks for freedom and full range of movement. It is important to consider                      (i) the criticality of the task and consequences of failure,                                                          (ii) the vulnerability of the task to human error (which might be determined by previous incidents, a risk assessment, etc)    ...

           Functional checks are error capturing mechanisms in some instances since they will detect, if properly actioned, if something is not installed, secured properly, adjusted correctly or meets specified criteria in the manuals. This is true for most systems and is an inherent part of the maintenance process.          It is, in the majority of cases, impossible to carry out a duplicate inspection on a flying control without a function check since the range of movement, control stop clearances, control system friction or loading checks cannot be determined otherwise.                 The problem is that since they are regarded as an inherent part of the system, complacency can set in concerning their purpose and value. It is only when the function checks or ground runs are not carried out and an incident occurs, (e.g.  double engine oil loss on a 737-400 at Daventry) that their ...

           Whilst the system should aim for error avoidance, it is not always possible to prevent errors from happening, in which case, the next best thing is to detect them and prevent them from resulting in harm.                                                    The only sure way to be totally safe in aviation is to keep aircraft on the ground, but this is only an option in very extreme cases.        In normal operations, circumstances known to be vulnerable to error can often be avoided, or additional checks put in place to capture errors if they do occur.                                                     One example is work carried out when maintenance personnel are like...

 It is an ICAO standard for all organisations involved in the design, production, operations and maintenance of aircraft to have an occurrence reporting system. Part145.A.60 requires all Part-145 approved organisations to report occurrences meeting certain criteria1 to the competent authority, state of registry and organisation responsible for the design of the aircraft. Whilst this requirement is primarily intended for technical problems affecting aircraft, it also extends to errors where these have resulted in "any condition of the aircraft or component....that has resulted, or may result, in an unsafe condition that hazards seriously the flight safety" (Part145.A.60(a)). This could include, for instance, failure to refit O-ring seals when replacing chip detectors. In any case, each Part-145 approved organisation is required to have in place a system for the reporting, collection and evaluation of occurrences, the aim being "to identify the factors contributing to in...

 Evidence indicates that maintenance personnel often fail to comply with procedures. Part-145 necessarily requires, and assumes, compliance with procedures, but also addresses some of the issues which lead to non-compliance (e.g. poorly written procedures, unavailability of appropriate maintenance data or tooling, time pressure, etc.). “Procedures are not used because...                                    %agreeing                        Accuracy   ..they are inaccurate             21                                                                                        ...

 A working definition of “human error” (including violations) is “those occasions in which a planned sequence of mental or physical activities fails to achieve its intended outcome, and when these failures cannot be attributed to the intervention of some chance agency”.              It is useful to distinguish, right from the outset, the difference between "human error" and "system error".  Whilst it is always a human being who commits the error, there are two approaches to looking at error:  (i) from the point of view of the individual and  (ii) from the point of view of the whole system, of which the individual technician is only one part.  The concept of "maintenance error" is sometimes equated to "system error". Another useful way of looking at error (and violations) is in terms of system component failure, where human actions are part of the system and need to be engineered such that they are resistant to error and, in the...