Physical Work and Repetitive Tasks (9.6.1-2) PDF

Physical Work and Repetitive Tasks (9.6.1-2) Learning Objectives 9.6.1 Recall necessary steps for planning complex maintenance tasks, including considerations for physically demanding tasks (Level 1). 9.6.2 State the main dangers of maintenance workers carrying out repetitive tasks, i...

Physical Work and Repetitive Tasks (9.6.1-2) Learning Objectives 9.6.1 Recall necessary steps for planning complex maintenance tasks, including considerations for physically demanding tasks (Level 1). 9.6.2 State the main dangers of maintenance workers carrying out repetitive tasks, including bias, complacency and assumptions (Level 1). Summary This chapter examines the nature of the tasks that AMEs carry out, looking at the physical work, repetitive tasks, visual inspection and complex systems that they work on. 2023-01-12 B-09 Human Factors Page 203 of 340 CASA Part 66 - Training Materials Only  Physical Work Planning for the Work It is best to start a task by scoping and planning. Before commencing a task, an individual maintenance worker, engineering team, manager or planner should ask themselves a number of questions. These may include: Do I/we know exactly what the task is that has to be done? Are the resources available to do it effectively (safely, accurately and within the time permitted)? Resources include: Suf cient personnel Equipment/tooling/spares Documentation, information and guidance Facilities such as hangar space, lighting, etc. Do I/we have the skills and pro ciency necessary to complete the task? Within Maintenance and Repair Organisations (MROs), information about speci c tasks should be detailed on approved job cards or task sheets. These will indicate the task (e.g., checks or inspection, repair, replacement, overhaul) and often further details to aid the engineer (such as maintenance manual references, part numbers, etc.). If there is doubt about what needs to be done, written approved data is usually the best resource. Colleagues may unintentionally give incorrect or imprecise direction (the exception to this is when discussing problems that arise that are not covered in the approved data). 2023-01-12 B-09 Human Factors Page 204 of 340 CASA Part 66 - Training Materials Only  Resources It is generally the maintenance planner and shift supervisor’s job to ensure that the resources are available for the staff to carry out their tasks. It is likely that, within a shift or a team, various sub- tasks are allocated to individuals by the supervisor. Alternatively, a team may be encouraged to take ownership of the tasks that need to be completed, giving them the discretion to manage a package of work. Image by Science in HD on Unsplash The maintenance planner and shift supervisor’s should ensure that all required resources are available for the staff to carry out their tasks Skills and Pro ciency Required Exactly ‘who does what’ tasks is likely to be based on factors such as individuals’ trade specialisation (mechanical, structures or avionics) and their experience with the aircraft type and/or the task. Although management are responsible to ensure that their engineers have suitable training, the individual engineer must decide whether they have the necessary skills and the pro ciency and experience to do what they have been asked to do. Maintenance workers should be con dent enough to raise any misgivings or reservations about their ability to do the work. Peer and management pressure may make this dif cult, but it is critical for maximum safety and ef ciency. 2023-01-12 B-09 Human Factors Page 205 of 340 CASA Part 66 - Training Materials Only  Physical Tasks Aircraft maintenance engineering is an active occupation. Regardless of the job being done, most tasks tend to have elements of ne hand skills requiring precision, as well as activities requiring strength and gross manipulation. The human body is a series of physical links (bones) connected at certain points (joints) that allow various movements. Muscles provide the motive force for all movements, both ne and gross. This is known as the musculoskeletal system. The force that can be applied in any given posture depends on the strength available from muscles and the mechanical advantage provided by the relative positions of the load, muscle connections, and joints. Most maintenance tasks tend to have elements of ne hand skills requiring precision, as well as activities requiring strength Physical Condition of Workers To conduct many maintenance tasks, strength and physical condition are important. This is not to say that many maintenance tasks cannot be adequately carried out by people with physical disabilities. But often the work requires physical abilities, including walking and working in tight spaces. As an engineer gets older, the musculoskeletal system becomes less exible and muscles become weaker. Injuries become more likely and take longer to heal. Staying in good physical condition will minimise the effects of ageing, but they still occur. 2023-01-12 B-09 Human Factors Page 206 of 340 CASA Part 66 - Training Materials Only  Design of Aircraft to Allow Access It is important that maintenance tasks on aircraft are within the physical limitations of AMEs. Boeing use a computerised tool, based on human performance data (body sizes, strengths, leverages, pivots, etc.), to ensure that modern aircraft are designed such that the majority of maintenance engineers will be able to access aircraft equipment, apply the necessary strength to loosen or tighten objects, etc. That is, they are designed for ease of maintainability. Image by nrd on Unsplash Modern aircraft are designed such that the majority of maintenance engineers will be able to access aircraft equipment 2023-01-12 B-09 Human Factors Page 207 of 340 CASA Part 66 - Training Materials Only  Tools to Help with Physical Tasks Clearly, we are all different in terms of physical stature and strength and as a consequence, our physical limitations vary. Attempting to lift a heavy object which is beyond our physical capabilities is likely to lead to injury. The use of tools generally makes tasks easier, and in some situations, may make a task achievable that was hitherto outside our physical powers (e.g., lifting an aircraft panel with the aid of a hoist). © Aviation Australia Tools generally makes tasks easier, and specialist tools make speci c tasks achievable that otherwise could not be done Fatigue Physical work over a period will result in fatigue. This is not a problem if there is adequate rest and recovery time between work periods. It can become a problem if the body is not allowed to recover, possibly leading to illness or injuries. Hence, maintenance workers should try to take their allocated breaks, and not avoid coming to work if overly fatigued. Missing a break in an effort to get a job done within a certain time frame can be counterproductive, as fatigue diminishes motor skills, perception, awareness and standards. As a consequence, work may slow, and mistakes may occur that need to be recti ed. Maintenance workers should try to ensure that their physical tness is good enough for the type of tasks they normally do. 2023-01-12 B-09 Human Factors Page 208 of 340 CASA Part 66 - Training Materials Only  Repetitive Tasks Introduction Repetitive tasks can be tedious and reduce arousal (i.e., be boring). Most of the human factors research associated with repetitive tasks has been carried out in manufacturing environments where workers carry out the same action many times a minute. This can also happen in aircraft maintenance, but it is not as typical as factory work. Repetitive tasks in aircraft maintenance engineering are typically tasks that are performed several times during a shift, or repeatedly during a short time period, e.g., in the course of a week. An example of this is checking life jackets on an aircraft during daily inspections. Some engineers may specialise in a certain aspect of maintenance, such as engines. As a result, they may carry out the same or similar tasks several times a day. Image by thaianeoliveira from Pixabay Repetitive tasks can be tedious 2023-01-12 B-09 Human Factors Page 209 of 340 CASA Part 66 - Training Materials Only  Beware of Bias, Complacency and Assumptions The main danger with repetitive tasks is that they become routine. Maintenance workers may become so practised at such tasks that they may cease to consult the maintenance manual or to use job cards. Thus, if something about a task is changed, the maintenance worker may not be aware of the change. Elsewhere, these notes discuss expectancy bias in which if the same inspection is carried out many times with the same result, then the inspector starts to expect the same result always. This bias is also strongly linked to complacency, whereby a maintenance worker may skip steps or fail to give due attention to steps in a procedure, especially when checking something which is rarely found to be wrong, damaged or out of tolerance. This applies particularly to visual inspection, which is covered in greater detail in the next section. As discussed, maintenance workers must constantly challenge bias, complacency and assumptions. Sometimes we need to ‘promote constructive worrying’. In other words, be concerned, not complacent, about what may happen in the future. If you are involved in repetitive tasks, be conscious that the next time you do the task may result in a different outcome. 2023-01-12 B-09 Human Factors Page 210 of 340 CASA Part 66 - Training Materials Only