Human Factor

Potential Hazards in Aircraft Maintenance  very bright lights (e.g. from welding); very loud sounds (sudden or continuous);  confined or enclosed areas; working at significant heights; noxious substances (liquids, fumes, etc.); excessive temperature (i.e. too cold or too hot);  moving equipment, moving vehicles and vibration. Health and safety policy Carry out assessments of work including inspections to determine H&Safety risks; Provide safe working practices and procedures for plant, machinery, work equipment, materials and substances; Inform employees and other persons including temporary workers of any risk; Provide suitable training and/or instruction to meet any Health and Safety risks; Develop and introduce practices and procedures to reduce risks to Health and Safety including the provision of special protective devices and personal protective equipment; Provide for the welfare of employees; Discuss with and consult employee rep...

Human information processing  have limitations.   AMT requires support such as reference  to written material (e.g. manuals). Attention and Perception -  A proportion of ‘sensed’ data may be lost without being                              ‘perceived’.   Failing to  perceive  something  which   someone  has said to you, when you are concentrating on something else, even  though the words would have been received at the ear without any problem.  Information processing system has  ability  to perceive   something (such as a picture,                       sentence, concept, etc.) even though some of the data  may be missing.  Danger - people can fill in the gaps with  information from their own store of knowledge or experience, and this may lead to  t...

  SMS provide a means of achieving enhanced safety performance which meets or exceeds basic compliance with the regulatory requirements associated with safety and quality. It is a well-established fact that enhanced safety performance is founded upon a proactive safety culture inherent in all the organisation’s safety-related activities.  A corporate approach to safety must be able to meet the following criteria: • Published safety accountabilities of managers and key staff • Requirements for a safety manager • The ability to demonstrate that it generates a positive safety culture throughout the organisation • Documented business policies, principles and practices in which safety is inherent • Commitment to a safety oversight process which is independent of line management • Regularly reviewed safety improvement plans • Formal safety review process The second essential prerequisite is for an organisation that delivers safe standards by way of: • Effective arrangem...

 Where procedures allow some leeway, AMT often develop  their own strategies or preferred way of carrying out a task. Often, a ‘good’ rule or  principle is one that has been used successfully in the past.  These good rules become   ‘rules of thumb’ that an engineer might adopt for day-to-day use.  Problems occur   when the rule or principle is wrongly applied. For example, aircraft pipe couplings are   normally right-hand threads but applying thi  s ‘normally good rule’ to an oxygen pipe   (having a different thread) could result in damage to the pipe. Also, there can be   dangers in applying rules based on previous experience if, for example, the design philosophy differs, as in the case of Airbus and Boeing. This may have been a factor in an A320 locked spoiler incident, where subtle differences between the operation of the spoilers on the A320 and those of the B767 (with which the engineers were more familiar) meant that act...

S kill, rule, knowledge-based errors; Skill-based behaviours  are those that rely on stored routines or motor programmes that have been learned with practice and may be executed without conscious thought. Rule-based behaviours  are those for which a routine or procedure has been learned. The components of a rule-based behaviour may comprise a set of discrete skills. Knowledge-based behaviours  are those for which no procedure has been established. These require to evaluate information, and then use  knowledge and experience to formulate a plan for dealing with the situation.”

S lips, lapses and mistakes ;  Slips  can be thought of as actions not carried out as intended or planned, e.g. ‘transposing digits when copying out numbers, or misordering steps in a procedure. Lapses  are missed actions and omissions, i.e. when somebody has failed to do something  due to lapses of memory and/or attention or because they have forgotten something, e.g.  forgetting to replace an engine cowling.    Mistakes  are a specific type of error brought about by a faulty plan/intention, i.e. somebody  did something believing it to be correct when it was, in fact, wrong, e.g. an error of  judgement such as mis-selection of bolts when fitting an aircraft windscreen.          Violations  sometimes appear to be human errors, but they differ from slips, lapses  and mistakes because they are deliberate ‘illegal’ actions,

PEAR model is developed by Dr. William Johnson and Dr. Michel Maddox specifically with the maintenance in mind. P - People - who do the job E - Environment - in which they work A - Action they perform R - Resource -necessary to complete the job.