Maitenance Error Management Airworthiness Requirements

Published Date: 02 Nov 2017

Local Errors:

Human errors especially in aircraft maintenance did contribute to a lot of incidents and even paved the way for some disastrous air accidents. Many surveys and reports quote that majority of the incidents are caused due to human errors. It’s not correct to put the blame directly on the maintenance personnel as they must be placed in situations and task factors or work environment that directly or indirectly responsible for errors. Those tasks, conditions which were responsible and were present in the working environment are commonly referred to as local errors. It was listed in a survey carried by airbus on maintenance error management that though there are many factors that are reported in an incident but there are few issues that are being repeated. This shows that when carrying any maintenance task in a work place ; if the issues which are repetitive were concentrated more and were given utmost most importance there are chances to reduce the probability of error occurring. Listed below are the few key factors that are more likely responsible for promoting errors in a work place.

Documentation

Time pressure

Housekeeping

Fatigue

Documentation:

This factor holds a key point as it is the area where errors can creep in leading to faulty maintenance. The jobs in maintenance mainly do start and end with documentation. Documenting the tasks that are carried in work place is really important as it plays a vital role during shift handovers and provides a means of safety and reliable tool for the personnel who have no previous knowledge of the task. It is tool which is useful in presenting the system performance and also illustrates the procedure in order to do a task. While considering the normal day to day activities of maintenance personnel it was revealed that they spend most of the time signing off tasks, referring log books, maintenance manuals when they are off aircraft maintenance. Unfamiliar or new tasks need more documentation to be done as it provides a better understanding on system performance. But there is a chance of errors creeping in because as more times the task is done there is a chance of personnel become complacent to the task resulting in carrying the task purely basing on knowledge. It may prove fatal if the procedure changes so it’s better to opt for appropriate maintenance manuals or technical logs. Looking into the paper records it was clearly evident that in many incidents poor documentation played a prominent role and those records which hold unrealistic or unworkable paved the ways for violations. It is the management responsibility that maintenance personnel were provided appropriate training on the documentation they provide while carrying a task and in designed in a way that was clear and understandable. It is better to design manuals in simple English or it would be better to put them in the regional language. Even small improvements could reduce the errors in a work place.

Time Pressure:

All the airlines aim to keep most of their aircrafts in service rather on ground as it would affect their profits. This factor is having been an issue from the early days of flight. There are methods and measures that have been suggested and adopted to minimise the time of maintenance but yet this factor was still an issue as it lead to many incidents. Aircraft operators strive a lot to keep the aircraft out of service as early as possible which was directly imposing pressure on the maintenance personnel and was forcing them to cut corners in the procedures putting in danger the safety of aircraft. With the development of technology there are new methods that are introduced in maintenance like built in self testing and self healing techniques providing a scope for the errors to be directly displayed. This reduces the scope of errors and cutting corners in procedures; favouring towards rigid and specific fault maintenance within in stipulated time deadline. These systems play a vital role when the pressure on the personnel is more. It was clear in a survey this factor was the major issue that was responsible for most of the incidents. Though the skipping of steps in procedures seems to be safe but the actual scenario would be worse if things go wrong. Below graph provides an idea on contribution of skipping steps in procedures due to time pressure.

The graph shows that time pressure is one of the major factors contributing to unsafe maintenance practises causing a threat to safety.

Communication :

This is one such area which seems to be that there are chances of errors creeping would be less but does contribute more for error occurrence. As part of maintenance this is a powerful tool as any miscommunication among team member would prove fatal outcomes. In US a survey is carried to detect the most challenging problems that maintenance personnel’s are facing and the common answer is that lack of proper communication or dealing with people. This situation becomes an issue mainly working in a team, during shift handovers or documenting the task carried. During shift handovers it is really important to present the amount of work or the area of work done because it enables the next shift people know the extent of work carried and carry on with rest of the task. It was quoted in a survey that 12 percent of occurrences are due to lack of team work, misunderstandings, poor communications. So in order to over these issues companies must assign non technical tasks like managing people, working in a team, leadership. This was equally important as it does contribute to safe and reliable maintenance practises.

Housekeeping and tool control:

Housekeeping is the way where the tools and equipment are tracked. It was one of the powerful tools as it can account for more or less errors in a work place. This is the area which was responsible for keeping track on the equipment that was used by the maintenance personnel and appropriate labelling of the disassembled components. This is the true reflection of organisational culture of an airline as they present us the way the task is carried. It is inappropriate to leave equipment in work place without placing them in their respective positions as they may cause mismatch of components while the task was carried by other maintenance personnel. Housekeeping is the key area where the chances of error occurring seems to be low besides error levels would be relatively high if there are inappropriate tool control and poor housekeeping practises adopted.

Design Organisational Approval Analysis:

In the previous analysis we have seen the provoking factors that are mainly responsible for the errors in a work place. In this part the requirements for Design organisational approval those required or specified by Joint Aviation Authority (JAA) and European Aviation safety Agency are analysed.

For an organisation to hold a type certificate it must hold appropriate approval of its design organisation. It is more likely concentrated on the designer’s point of view not the manufacturer. As per the requirements of EASA for an organisation to gain a TYPE certificate it is mandatory that the design organisation standards comply with the standards those specified by them. There are set of alternative methods which provide a sensible means and can comply with the standards required but in the case of major design changes they can be done under Supplemental Type Certificate to the actual type certificate design. The uses of alternative design techniques are presently under consideration to implement them in certain project areas. As they are used alternative to design approval few manual methods are to be specified in order that they do not affect the actual required standards those quoted by part 21 requirements. In case the organisation used alternative techniques showing the absence of their DOA the investigations are held under the procedure of ‘Alternative Procedures for Design Organisation Approval’ of EASA.

2.1) Characteristics of Design Organisation:

The following are the main characteristics of design organisations.

Primary duty is to design a product

To see that that designed product comply with the standards, rules and regulations more importantly complying with the design requirements and standards

The products those designed by the organisation should contribute for the growth of more airworthy and reliable systems

The regulatory bodies are to be presented with appropriate documentation which enables them to know whether the organisational approaches are safe and reliable towards the design practises.

The regulatory bodies should be allowed to check or test any design or flight in order that the organisation documents are updated, safe to carry out design practises.

All the above characteristics are vital for design organisation approval but besides if for any reason the design needs to be changed and the changed design needs an approval the DOA alone cannot handle these issues. There is system that must be included along with DOA which supervises and controls the design changes. It was called as Design Assurance System and it does used for the approval of design changes and for constantly monitoring airworthiness standards.

These are the characteristic features of design assurance systems that made it an integral part of DOA.

‘Control the design.

Show compliance with the applicable certification standard and environmental requirements.

Show compliance with protection requirements.

Independently check this compliance.

Liaise with the Agency.

Continuously evaluate the design organization.

Control subcontractors’

(Florio, 2006)

The system monitoring does play a crucial role as it ensure all the responsibilities of DAS are discharged and suggesting preventive measures for a more healthier system. If there are any issues related to quality assurance they have to be reported immediately and the person holding responsibility for this issue is design organisation head.

After designing a product and for the approval of the component it is must that it complied with all the design requirements and signed off by the head of the design organisations as DECLARATION OF DESIGN COMPLIANCE which was prescribed in part 21of EASA paragraph 21A.20.

One of the key issues that were advantageous for the DOA is that they were shown by some privileges. The documentation of certain components - if they comply with required standards they have an option or skip further verification process and can be approved.

It would be better that an organisation adapt DOA as there are privileges involved in them which lay the foundation for better design organisational approval system. Many authorities have their own way of certification process and could be expensive some times which would be a barrier for that organisation. This clearly portrays the inefficiency of the system so it will be the responsibility of the organisation if there are any issues that may prevail due to safety.

As few alternative methods are used in the place of DOA it leads to loss of certain organisational privileges. This situation is mainly seen in the case of small organisation which uses them in place of DOA but it is recommended that they too must include DOA if though it was optional. As this does not compromise the air safety and lay the foundation for rigid design practises.

These certification processes are very important in both safety and design perspective as it’s not good to neglect or give less importance to safety issues because they may certainly lead to worse situations.