HUMAN FACTORS CONTINUATION TRAINING Q1&Q2 2018

Transcription

1 HUMAN FACTORS CONTINUATION TRAINING Q1&Q Page 1 of 10

2 CONTENTS: 1 INTRODUCTION 2 REVISTING THE PEAR MODEL- ACTIONS 3 TOOL CONTROL 4 YAK52 INCIDENT 5 IMPORTANCE OF CHECKLISTS 6 O2 BOTTLE REPLACEMENT Page 2 of 10

3 1. Introduction Human Factors is the application of what we know about human capabilities and limitations in order to maximize overall system performance. By giving careful consideration to the interactions between humans and technological and organisational elements of a system it is possible to significantly increase the system s productivity and reliability. Human Factors addresses the interaction of people with other people, with facilities and with management systems in the workplace. These factors have been shown to have an impact on human performance and safe operations. Human Factors provide practical solutions to reduce incidents while improving productivity. In the aviation industry Human Factors is an essential component in the effort to operate in a safe and efficient manner. Areas where Human Factors has a key role include: Design of tools, equipment and user interfaces in a way that augments the user s work performance Human and organizational factors in risk assessments and emergency preparedness planning Human behaviour and cognition in accident causes Efficient decision making and teamwork in stressful or critical situations Safety culture and safety behaviour improvement programmes Organisational reliability The aviation industry has a major accident potential. All aspects rely on advanced humanmachine interfaces, and are activities with a complex organisational structure. Increasingly, the work is performed by distributed teams all around our network. Human Factors has become an important and integral part of the industry s approach to safe and efficient operations. Page 3 of 10

4 2. Remember PEAR (part 3)? It stands for: People who do the job. In this case maintenance engineers and support staff. It includes not only our capabilities and limitations, but also our interactions with others. Environment in which they work. Both physical and organisational. Actions they perform to complete the job efficiently and safely. Resources necessary to complete the job. Physical, such as tools and technical manuals, as well as the number and qualifications of the people necessary Page 4 of 10

5 A is for Actions: to perform to complete the job efficiently and safely Steps to perform a task Sequence of activity Number of people involved Communication requirements Information control requirements Knowledge requirements Skill requirements Attitude requirements Certification requirements Inspection requirements Your actions have consequences. This is the reason it is important that we bring all our awareness and skill to every maintenance task we perform. When working together in a team communication or miscommunication leads to errors. Actions include your action in a maintenance task. What skills, procedures and resources are required in order for you to perform your duties? 3. Tool Control Tool control/ Tool Accountability has become a must of the aviation industry not only to prevent the leaving of tools on aircraft but also to increase efficiency while working on aircraft. A decrease in the time spent by an engineer/ technician to find a tool, can help speed up the overall maintenance inspection completion time. Tool quality control issues cost the industry over 500 million every year. This is due to lost tools, broken but not replaced tools, tools that are not right for the job, and misplaced tools. In addition, the most critical quality problem is tools accidentally left in aircraft after maintenance. In these circumstances, it is understandable that tool control must be improved. Unfortunately, a recent study shows that this is either not the case or it is not being implemented as fast as it should. The main themes in the aircraft maintenance industry are cost savings and control. Control of tools is a key factor as this ensures that the work is being done with the right tools, calibrated tools and that no tools are left in areas they should not. A big part the implications of lack of control is lost time, mistakes, and rework. These issues lead to increased costs, health and safety issues, and, potentially, lost business. Tool control also involves calibrating tools. This ensures that the torque figures are correct. In controlled environments, lost tools can be accounted for. And broken tools can be replaced to ensure downtime is keep at a minimum. Page 5 of 10

6 Foreign object damage (FOD) creates $4 billion in cost every year to the aviation industry. A big part of that comes from inadequate tool control. These days, companies will have weekly, monthly and yearly audits on personnel tool boxes which therefore means less accidents can happen Every maintenance company will have a series of audits to determine if they are carrying out maintenance to a satisfactory level of airworthiness, during these audits Tool control and tool accountability plays a large factor in this. Tool control does not only help reduce audit findings, but also creates a much more organised and highly efficient working environment. Tool Control can be achieved in a number of ways: 1. Tool Shadow Boards- These are simply a wooden board or cupboard that has been painted white and has a black silhouette of each tool hanging from it. This is a cheap form of tool control. 2. Tool Dual Layer Foam Inlays- This is the preferred choice of most aviation maintenance companies, this can be applied to any tool box, tool stores etc. It is created by having a cut out either via laser or CNC mill made into a dual coloured foam enabling the user to easily identify missing tools. 3. RFID Control- Radio Frequency Identification is a new method of tool control, using a series of RFID tags and Readers, the user and management staff have the ability to track the use and movements of a tool. Tool Tracking Many factors contribute to aircraft maintenance failures. One area that can contribute to reducing these problems is by managing the availability and use of the tools and tooling that are an essential part of the maintenance environment. With effective tool tracking it becomes possible to ensure that all tools are issued against a job reference, returned at the end of a job; that the identity of an engineer checking out certain tools is recorded and, that tools are maintained and serviced adequately, this can be scheduled, monitored and audited. However, keeping track of tools with manual methods, using clipboards and forms, is both time consuming and error prone. There are ways of tracking tools that are available to the market today. These methods can include tool stores, tool kits, and computerised scanning. A new method that recently hit the market is the use of RFID chips which when scanned using radio frequency, respond with predetermined codes therefore linking the person that has them and the job they are on at the time. It also allows tool tracking. If a tool is lost, it can be found faster as the areas that the engineer was working on can be scanned and quickly determine whether the tool is there or not. Keeping track of hand tools and parts can be a very labour intensive process and very costly if the right methods are not employed. The reason why this article is important is that it highlights the main point that tool tracking does not have to be expensive. Simple methods like numbering tools or using bar-codes linked to a computer will give some level of tool tracking therefore the risk of lost/misplaced tools is reduced. Page 6 of 10

7 4. Yak-52, G-YAKW and the importance of tool control. Synopsis After a series of aerobatic manoeuvres the aircraft completed a stall turn and entered a vertical dive from which it did not recover. Examination of the wreckage revealed the presence of a short-handled flat bladed screwdriver that had jammed the elevator control such that the elevator control surface could not be moved beyond neutral in the nose-up direction Normal servicing, refuelling and the checking of engine oil levels requires the use of a tool to open various access panels. These panels are secured by quick release fasteners, which require a flat bladed screwdriver to open them. Most pilots of the Yak-52 carry with them a means to open the panels, either a screwdriver, a multi-tool or a 'Swiss Army' knife incorporating a screwdriver blade. The aircraft was recovered to the AAIB at Farnborough for a detailed examination. During an inspection of the aft fuselage section it was discovered that the elevators, although free to move in the nose-down direction, would not move beyond neutral when moved in the up direction. Examination of the aperture at the base of the tail on the top of the fuselage revealed a restriction that was preventing the aft elevator quadrant assembly from passing through the aperture. The restriction was discovered to be a small short-handled flat-bladed screwdriver, which had become impaled on the swaged end of the lower elevator cable at its attachment to the aft quadrant assembly A trainee mechanic at the maintenance organisation, upon hearing that a loose article had been discovered in G-YAKW, came forward and declared that he had lost a short-handled flat-bladed screwdriver matching the description of the item found in the aircraft. The trainee had started work at the maintenance organisation in September and had not worked on the aircraft during its 50 hour inspection. However, he did work on the aircraft in November. He does not recall ever using the screwdriver on the aircraft and only remembers using it to open a tin of paint away from the aircraft. Indeed the trainee was never given or accomplished a task that would warrant the use of such a screwdriver. This type of screwdriver is only used on tasks in difficult and restricted areas. The maintenance organisation also claimed that screwdrivers of this type are seldom used during normal maintenance carried out on the aircraft. Subsequent testing of the screwdriver removed from the wreckage, however, revealed DNA matching that of the pilot. This indicated that he had touched it at some time prior to the accident. The trainee's personal tools were located in two separate tool boxes at the back of the maintenance hangar. The tool boxes were never locked and were left open during the day but closed at night. The trainee had been made fully aware of the dangers of loose articles in aircraft and was reminded of this on many occasions by the more senior technicians and licensed aircraft engineers (LAE). The borrowing of tools did take place at the organisation and the policy was for the owner to be asked beforehand, but if the owner was not present, items could be borrowed without his knowledge. The owner however remained responsible for his own personal tools including ensuring that they were all present and correct. There was no formal tool control at the maintenance organisation. Page 7 of 10

8 Loose article checking was carried out at the maintenance organisation. The onus was placed on the person who carried out the task to ensure that all tools, materials and any other foreign items were removed from the aircraft following accomplishment of the task. The area would then be checked by the LAE prior to signing the task on the work sheets. Before a panel was closed, the area would be checked at least twice and in some cases three times, for loose articles prior to closure. However none of these actions were formally recorded in the work sheets 5. Importance of Checklists In spite of all the advancements in managing aircraft maintenance information and behaviour, we all benefit when the task is simplified. Safety begins with how we see things on the hangar floor. It s easier when the tools we use help us exercise more control over our work environment. Process-driven actions on the hangar floor do not have to be cumbersome or complex. Let s begin with a discussion of a tool everyone knows: the checklist. Do you use one for an inspection? When the checklist was written what thought was given to what it should contain or what use could be made of it? What was its purpose when it was developed and how is it used? The checklist is the basic production and control tool. It starts as a to-do list. We can incorporate these tasks into a checklist format. In fact we could just roll along with a check mark in each row as we accomplish work on the aircraft. Computers have managed to morph the checklist into a powerful device that can be so much more than a to-do list. By adding a heading and additional column we have a better record of our performance and the performance of others. We can track progress of personnel to whom we assign work, as well as create a record of current status to remind ourselves of where we are in the inspection process. (That s good if we are working by ourselves.) From a project management perspective, we have an idea of where we are, who has done what and what s left. Checklists are adaptable and can serve many purposes: Production tool: It can be the basis for establishing an estimate of the work write man-hours or job time in the mechanic block as a work sheet. Add it all up and see if you have enough hours in the day to do the work. Inspection diary/turnover record: It can be a task reminder of where we are and what is going with the aircraft. A work turnover is a diary of the day s activities. Entries are safety related as well as information of concerning incomplete work. Some examples include: Rig pin or lock pin installations, circuit breakers status safety prohibitions to actuation of a system, safety issues related to explosive actuated systems, wet paint, and operational checks requirements. Page 8 of 10

9 Yes, you can make a turnover if you are the only one on the job or if there is only one shift. Having a tool that reminds us of what we already know and keeps us from making embarrassing omissions. It s important that personnel record the last step accomplished in an interrupted procedure to assure that work doesn t begin at the wrong place. Record of material history and component control Material issues can be recorded in the checklist to show component changes. Component removal and installations are important items to include with any work order. A separate section of the checklist format can be created for attachment or printed on the reverse side of the checklist. Once completed, they create a history of parts information related to the work order. Independent Inspections From a human factors point of view, the act of inspecting another s work needs to come with mutual acknowledgment by both parties that errors found are not a personal reflection of a mechanic s technical competency. In fact, there is a tendency for the most egregious errors to be caused by the most experienced technicians since they are often the ones who are called on to perform the most challenging tasks. Though they are rare, the outcome of a slip or misjudgement on their part may result in more severe consequences. 6. O2 Bottle-Replacement Following a crew debrief relating to a cargo smoke detector defect, the engineer checked the crew oxygen contents as requested by the task card issued by the operator. The check identified the need to replace the upper oxygen cylinder as it was below the limits specified on the task card. The LAE asked a partner companies team of engineers to replace the oxygen cylinder whilst he continued with the troubleshooting and rectification of the inbound defects. This was common practice for both groups of engineers to help each other out when the unplanned workload increased. The LAE had worked with both the supplied type rated engineers previously and was happy with their competence to perform the task. Having rectified the other issues, the LAE proceeded to inspect the installation of the newly installed crew oxygen cylinder. During his inspection he checked the cylinder for security and he also viewed the cylinder shutoff valve to check this was fully on. As the other engineers had already safety wired the valves, he decided that viewing the length of the shutoff valve shafts was sufficient to determine if the cylinders were fully open. He followed this up with a pressure drop check as required by AMM, which states make sure the pressure does not drop more than 100 PSIG. The LAE noted during the test the pressure dropped PSI. This gave him confidence the valves were in the fully open position. He subsequently certified the work, and the aircraft was released to service. Page 9 of 10

10 Following a flight, the oncoming crew were unhappy with the pressure drop of the oxygen system during their pre-flight checks and requested engineers on station to check the cylinders. It was noted during the test, that the oxygen pressure dropped by 40PSI and then returned to original pressure. Engineers attending the aircraft inspected the cylinder valves and determined that the valves were not properly open. The valves were then fully opened and turned half round back. The aircraft was released to service and there have been no further related issues. Following an investigation, a similar oxygen cylinder and its shutoff valve were inspected in the fully open and closed positions. Due to the small difference in shaft lengths at the two different states, it was concluded that it is not possible to reliably determine if the cylinder has been fully turned on using a visual comparison method. The AMM states that the valve for both cylinders are to be turned to the fully open position. Then, turn each shutoff valve 1/4 -turn in the opposite direction. Following a MEDA investigation, it was noted that the LAE used a non-approved inspection method and failed to follow the approved maintenance data. The MEDA Investigation also highlighted the differences in the acceptable pressure drop as stated in AMM system operational test and the flight crew pre-flight checks. Page 10 of 10