Physical Environment (9.5) PDF

Physical Environment (9.5) Learning Objectives 9.5.1.1 De ne noise, state the effects of noise and recall methods of hearing protection (Level 1). 9.5.1.2 De ne fumes, state the dangers and effects of fumes, how to detect fumes and recall methods of protection (Level 1). 9.5.2 Stat...

Physical Environment (9.5) Learning Objectives 9.5.1.1 De ne noise, state the effects of noise and recall methods of hearing protection (Level 1). 9.5.1.2 De ne fumes, state the dangers and effects of fumes, how to detect fumes and recall methods of protection (Level 1). 9.5.2 State the need for natural and arti cial light in a workplace, for both ambient and task illumination (Level 1). 9.5.3 Recall that humans work best within a narrow temperature range but operational pressures often dictate that tasks must be carried out in heat, cold, poor weather (Level 1). 9.5.4.1 Recall that motion makes objects more dif cult to inspect (Level 1). 9.5.4.2 Recall that vibration can have an effect on the human body (Level 1). 9.5.5.1 State examples and aspects of the physical work environment that allows people to work safely and ef ciently (Level 1). 9.5.5.2 De ne what constitutes the overall working environment and measures to ensure safety (Level 1). Summary Aircraft maintenance workers can expect to work in a variety of different environments, from of ces, for certain clerical and managerial job roles, component overhaul workshops, line maintenance (generally outside the hangar) and base maintenance (usually inside a hangar or large workshop). The work performed outside is subject to all types of weather and climatic conditions, and many job roles work a rotating roster of day and night shifts. Maintenance organisations may also have trades assistants who spend the majority of their time outdoors. The nature of work and the environment in which the work is done depends largely on the company, and the job functions in that company. Physical environments have their own speci c features or factors that affect human performance. This chapter considers the impact of noise, fumes, illumination, climate and temperature, motion and vibration, the requirement to work in con ned spaces and issues associated with the general working environment. 2023-01-12 B-09 Human Factors Page 184 of 340 CASA Part 66 - Training Materials Only  Noise and Fumes Noise Noise can be de ned as unwanted sound. It is problematic, especially if it is loud, unpleasant and annoying. Short and Long-Term Effects Noise in the workplace can have both short-term and long-term negative effects: it can be annoying, can interfere with verbal communication and mask warnings, and can damage workers’ hearing (either temporarily or permanently). The intensity of sound is measured in decibels (dB), where exposure in excess of 115 dB without ear protection even for a short duration is not recommended. This equates to standing within a few hundred metres of a moving jet aircraft. Hearing Protection General background noise can be ltered out by the brain through focused attention. Otherwise, for more problematic noise, some form of hearing protection (e.g., ear plugs and ear muffs) is commonly used by AMEs, both on the line and in the hangar, to help the engineer to concentrate. Image by Clker-Free-Vector-Images from Pixabay Some form of hearing protection (e.g., ear plugs and ear muffs) is commonly used by AMEs 2023-01-12 B-09 Human Factors Page 185 of 340 CASA Part 66 - Training Materials Only  The noise environment in which the AME works can vary considerably. For instance, on the airport ramp or apron area the noise level can exceed 85 dB - 90 dB which can cause hearing damage if the time of exposure is prolonged. The hangar area can also be noisy, usually due to the use of various tools during aircraft maintenance. Short periods of intense noise are not uncommon here and can cause temporary hearing loss. Technicians may move between these noisy areas and the relative quiet of rest rooms, aircraft cabins, stores and of ces. It is very important that aircraft maintenance workers remain aware of the intensity of the ambient noise. Some form of hearing protection should be carried at all times and, as a rule of thumb, used when in an area where normal speech cannot be heard clearly at 2 metres. In their day-to-day work, AMEs will often need to discuss matters relating to a task with colleagues and also, at the end of a shift, handover to an incoming engineer. Clearly, in both cases it is important that noise does not impair their ability to communicate, as this could have a bearing on the successful completion of the task (i.e., safety). Common sense dictates that important matters are discussed away from noisy areas. Fumes By its nature, aircraft maintenance involves working with a variety of uids and chemical substances. For instance, engineers may come across various solvents, lubricants (oils and greases), hydraulic uids, paints, cleaning compounds and solder. They will also be exposed to aircraft fuel and exhaust. In fact, there is every possibility that an engineer could be exposed to a number of these at any one time in the workplace. Each substance gives off some form of vapour or fumes which can be inhaled by the AME and may cause lung and eye irritation. In general terms, bits of airborne solid material in some fumes are called particles, and the gaseous material in fumes are termed vapour. Detecting Fumes Some fumes will be obvious as a result of their odour, whereas others have no smell to indicate their presence. Some fumes are detectable by electronic equipment. For example, fuel vapour level is measured prior to fuel tank entry. 2023-01-12 B-09 Human Factors Page 186 of 340 CASA Part 66 - Training Materials Only  Dangers of Fumes and Protection Fumes can cause problems for engineers mainly as a result of inhalation, but they can also cause other problems, such as eye and skin irritation. The problem may be increased in aircraft maintenance engineering by the con ned spaces in which work must sometimes be carried out (e.g., fuel tanks). Here the fumes cannot disperse easily, and it may be appropriate to use breathing apparatus. Depending on their size, airborne particles may be removed by wearing a particle mask, while full breathing equipment must be used to exclude vapours. It may not always be practical to remove fumes from the aircraft maintenance work environment, but where possible, steps should be taken to minimise them. It is also common sense that if harmful fumes are detected, the maintenance worker should immediately inform their colleagues and supervisor so that the area can be evacuated and suitable steps taken to investigate the source of the fumes and remove them. Image by Daniel Ramos on Unsplash Depending on their size, airborne particles may be removed by wearing a particle mask Apart from their serious health implications, fumes can affect a maintenance worker’s performance, as they may rush a job in order to escape them. If the fumes are likely to have this effect, the aircraft worker should increase the ventilation or use breathing apparatus. 2023-01-12 B-09 Human Factors Page 187 of 340 CASA Part 66 - Training Materials Only  Illumination The Need for Light The human eye is not designed to work well in low light. In order for AMEs to carry out their work safely and ef ciently, it is important that their work be conducted under proper lighting conditions. It was noted in previous sections of this module that the cones in the retina of the eye require good light to resolve ne detail. Furthermore, colour vision requires adequate light to stimulate the cones in our eyes. Inappropriate or insuf cient lighting can lead to mistakes in work tasks or can increase the time required to do the work. Illumination Illumination refers to the lighting both within the general working environment and also in the locality of the maintenance worker and the task they are carrying out. It can be de ned as the amount of light striking a surface. Natural and Arti cial Light When working in an aviation environment, it is common to work both in indoor and outdoor areas. Likewise, it is common to work in both daylight and at night. Therefore, the maintenance worker must become adept at working in both natural and arti cial light. Sometimes the natural light is too strong, and sunglasses are required. In other situations, arti cial lighting is required. Ambient Lighting Ambient light is the light in the general workplace area. It is designed to provide broad and relatively weak illumination, that allows people to move around the area safely and do day-to-day tasks. But ambient lighting it is not suf cient to conduct detailed inspections. For this, additional task lighting is required. Aviation Australia Ambient light is the light in the general workplace area 2023-01-12 B-09 Human Factors Page 188 of 340 CASA Part 66 - Training Materials Only  When working outside during daylight, a maintenance worker may have suf cient natural light to see well. It is possible however that speci c work areas may be in deep shadow or they may be working inside a building which makes the natural light dull. Glare is also a consideration when working in daylight. Glare from sunlight may make inspections dif cult. At night, airports are usually lit with oodlights and other lighting, which provide the background or ambient lighting. Often, these lights are insuf cient for an engineer to be able to see when conducting a speci c inspection on an aircraft. These lights are not designed for this purpose and additional lighting is always required at night. Poor ambient illumination of work areas has been identi ed as a signi cant de ciency during the investigation of certain maintenance-related incidents. It is equally important that lighting in ancillary areas, such as of ces and stores, is good. 2023-01-12 B-09 Human Factors Page 189 of 340 CASA Part 66 - Training Materials Only  Task Lighting In general, ambient area lighting in hangars is unlikely to be as bright as natural daylight. Therefore, local task lighting is often needed, especially for work of a precise nature, particularly visual inspection tasks. Work conducted inside cabin or cargo compartments, or in other dark areas like landing gear wheel wells will usually not be illuminated by enough ambient lighting to allow detailed inspection. These areas also require task lighting. The additional local arti cial lighting needed for speci c tasks may be as simple as a good torch or ashlight. There may also be larger lights that can be moved from one area to another. The drawback of a torch is that it must be held in one hand, leaving only one hand available to work. Some maintenance workers choose to use a light mounted on a headband. Torch batteries must be replaced regularly and it is wise to carry a spare set of batteries rather than attempt an inspection without enough light. Western Technology Additional local arti cial lighting may be needed for speci c tasks When using task lighting, it should be placed close to the work being done but should not be in the line of sight of people conducting visual inspections as this will result in direct glare. The lighting must also be positioned so that it does not re ect off surfaces near where the engineer is working causing indirect or re ected glare. Glare of either kind will distract from the task or will obscure the area and may cause mistakes. When glare is present, from bright lights or sunlight, then dark shadows may also affect the accuracy of visual inspections. 2023-01-12 B-09 Human Factors Page 190 of 340 CASA Part 66 - Training Materials Only  Climate and Temperature Human Performance Outside a Comfortable Temperature Range Humans can work within quite a wide range of temperatures and climatic conditions, but performance is adversely affected at temperature extremes. In the gure below, performance degrades when it is either too cold and/or wet or too hot and/or humid. Aircraft maintenance workers routinely work both within the hangar and outside in the weather. Exposure to the widest range of temperature and climate condition is likely to be encountered outdoors. Here, working conditions include direct summer sun, strong winds, heavy rain, fog, high humidity, and the cold of winter. Although hangars are built to exclude inclement weather, they can be cold and draughty, or very hot, especially if the hangar doors have to remain open. Heating and cooling systems may assist in regulating the hangar environment. Regulatory Guidance on Working Environment EASA Part-145, AMC 145.25 (c) states: ‘Hangars used to house aircraft together with of ce accommodation should be such as to ensure the working environment permits personnel to carry out work tasks in an effective manner. Temperatures should be maintained such that personnel can carry out required tasks without undue discomfort.’ Aviation Australia The relationship between climate, temperature and performance. 2023-01-12 B-09 Human Factors Page 191 of 340 CASA Part 66 - Training Materials Only  EASA Part-145 Acceptable Means of Compliance (AMC) 145.25(c) requires that environmental conditions be adequate for work to be carried out, stating: ‘The working environment for line maintenance should be such that the particular maintenance or inspection task can be carried out without undue distraction. It therefore follows that where the working environment deteriorates to an unacceptable level in respect of temperature, moisture, hail, ice, snow, wind, light, dust/other airborne contamination, the particular maintenance or inspection tasks should be suspended until satisfactory conditions are re-established.’ Operational Pressures In reality, work pressures usually prevent many maintenance tasks from being put off until the conditions are better for work. Environmental conditions can affect physical performance. For example, cold conditions make numb ngers, reducing dexterity when handling small parts and carrying out complex repairs. Hot conditions, caused either by climate or by proximity to hot engines, are uncomfortable and, like cold conditions, may require gloves or other PPE that can restrict movement and dexterity. Similarly, working in strong winds can be distracting, especially if having to work at height on high stands that move in the wind (or if the aircraft is moving in the wind). Environmental conditions that are outside the comfort zone of a human can be physically and mentally fatiguing. There are no simple solutions to the effects of temperature and climate on maintenance workers. For example, in the cold, gloves may be worn, but the gloves themselves may interfere with ne motor skills. It is the nature of the industry that maintenance work is carried out in less-than-ideal conditions. But it is essential that organisations and individuals recognise that these conditions may affect the quality of work carried out. There is a need to be extra vigilance in these circumstances. Photo by Sergey Svechnikov on Unsplash Environmental conditions can affect physical performance. 2023-01-12 B-09 Human Factors Page 192 of 340 CASA Part 66 - Training Materials Only  Motion and Vibration Motion When Working at Heights Aircraft maintenance workers often use stands, scaffolding and mobile access platforms to reach various parts of an aircraft. As these extend higher above the ground, they tend to become less stable. For example, when working at height on an elevated work platform, applying force to remove screws on a panel xed to the aircraft may cause the platform to move away from the aircraft, or the aircraft itself can move in the wind. The design and serviceability of the platform also in uence he steadiness of the work area. If it is too unsteady, the maintenance worker will concentrate more on keeping balance rather than on completing the task. Mobile access platforms must be used properly and safely to avoid serious injury. Mobile access platforms and safety harnesses must be used properly and safely to avoid serious injury 2023-01-12 B-09 Human Factors Page 193 of 340 CASA Part 66 - Training Materials Only  Inspection Tasks Motion of objects relative to each other (i.e., if the person or the object is moving) also makes visual cues and inspection more problematic. This includes vibration, as it can be impossible to see a small defect on an object that is vibrating. Vibration Vibration can be annoying, can disrupt concentration and can also affect vision. Vibration affecting either the inspector, or the object being inspected, will affect the quality of any visual inspection. If the vibration is continuous or prolonged, and the aircraft maintenance worker can’t escape it, it can have a detrimental effect on the health of the worker. Vibration in aircraft maintenance is associated with the use of rotating or percussive tools and proximity to other equipment, such as generators. Low frequency noise, such as that associated with aircraft engines, also causes vibration. Vibration between 0.5 Hz and 20 Hz is most problematic, as the human body absorbs most of the vibratory energy in this range. Some organisations provide kidney belts to staff who regularly conduct engine running. The belts tighten around the waist and reduce the effect of low frequency vibration on internal organs. The range 50 to 150 Hz is most troublesome for the hand and can be associated with Vibratory-induced White Finger (VWF) Syndrome. Oscillating tools such as pneumatic tools and some electrical tools can produce troublesome vibrations in this range and frequent use can lead to reduced local blood ow and pain associated with VWF. IOH Solutions – 2018 White-Finger (VWF) Syndrome 2023-01-12 B-09 Human Factors Page 194 of 340 CASA Part 66 - Training Materials Only  Working Environment Working Safely and Ef ciently Various factors affect the aircraft maintenance physical working environment. These factors affect how the work is carried out and the overall safety and ef ciency of the workers. Apart from those already discussed, other physical in uences include: Workplace layout and the cleanliness and general tidiness of the workplace (e.g., storage facilities for tools, manuals and information, are a means of checking that all tools have been retrieved from the aircraft, etc.). The proper provision and use of safety equipment and signage (e.g., non-slip surfaces, safety harnesses, etc.). The storage and use of toxic chemicals and uids (as distinct from fumes, e.g., clear labelling, safe storage and segregation etc.). Image from Pixabay on Pexels The proper provision and use of safety equipment and wearing of correct PPE 2023-01-12 B-09 Human Factors Page 195 of 340 CASA Part 66 - Training Materials Only  Suitability of the Working Environment Some or all of the factors associated with the maintenance worker’s workplace may affect their ability to work safely and ef ciently. For example, EASA Part-145.25(c) – Facility Requirements states: ‘The working environment must be appropriate for the task carried out and in particular special requirements observed. Unless otherwise dictated by the particular task environment, the working environment must be such that the effectiveness of personnel is not impaired.’ CASA Part 145 Manual of Standards 145.A.25 Facility Requirements states: ‘… the facilities must be to a standard that provides an environment that: 1. is appropriate to the weather conditions that prevail at the time that the maintenance is carried out; and 2. allows maintenance to be carried out: (i) at a comfortable temperature; and (ii) with appropriate levels of lighting; and (iii) without undue noise distraction; and 3. segregates specialised workshops and bays to avoid environmental and work area contamination; and 4. keeps airborne contamination, including dust, to a level that does not result in visible aircraft or aeronautical product surface contamination; …’ 2023-01-12 B-09 Human Factors Page 196 of 340 CASA Part 66 - Training Materials Only  The working environment must be appropriate for the task carried out and in particular special requirements observed 2023-01-12 B-09 Human Factors Page 197 of 340 CASA Part 66 - Training Materials Only  Components of the Working Environment The working environment comprises: The physical environment The social environment The tasks that need to be carried out. Each of these three components of the working environment interact, for example: Engineers are trained to perform various tasks Successful task execution requires a suitable physical environment An unsuitable or unpleasant physical environment is likely to be de-motivating. Components of the ‘working environment’ Aircraft maintenance requires all three components of the working environment to be managed carefully in order to achieve a safe and ef cient system Engineers generally attempt to do the best work possible regardless of their working environment. Good maintenance organisations do their best to support this dedication by providing the necessary conditions for safe and ef cient work. 2023-01-12 B-09 Human Factors Page 198 of 340 CASA Part 66 - Training Materials Only  Safety in the Working Environment While ef ciency is necessary, safety is critical. The aircraft maintenance environment is inherently dangerous, so individuals and organisations must stay safety conscious. Con ned Spaces Claustrophobia can be a problem in aircraft maintenance engineering. Work in any con ned space, especially with limited means of entry or exit (e.g., fuel tanks), needs to be managed carefully. As noted previously, engineers should ideally work with a colleague who would assist their entry into and exit out of the con ned space. Good illumination and ventilation within the con ned space will reduce any feelings of discomfort. In addition, appropriate safety equipment, such as breathing apparatus or ventilation equipment must be used when required. US Air Force – 2018 Work in any con ned space (e.g., fuel tanks), needs to be managed carefully 2023-01-12 B-09 Human Factors Page 199 of 340 CASA Part 66 - Training Materials Only  Working at Heights Approved equipment, such as scaffolding, elevated and mobile work platforms and fall-arrest equipment must be used whenever working in elevated areas. Depending on the local legislation, people may need to have speci c training before being approved to work at heights. Aviation Australia Elevated and mobile work platforms must be used whenever working in elevated areas Workplace Layout and Signage The oorplan and layout of a workplace should allow maximum ef ciency and safety. If hazards cannot be removed from the workplace, employees should be made aware that they exist and understand how to avoid them. This can be managed through training and warning signs. To be effective, warnings signs must: Clearly identify the hazard(s) Describe the danger (i.e., electric shock, radiation, etc.) Inform employees what to do or not to do. More information about hazards in the workplace can be found in further topics of this training. 2023-01-12 B-09 Human Factors Page 200 of 340 CASA Part 66 - Training Materials Only  Working Outdoors If working in a line maintenance environment, or working on speci c tasks outside in the weather, be conscious of weather conditions. Airports will have warning systems for extreme weather such as thunderstorms, and the tarmac area may need to be evacuated at certain times if there is real or potential danger from weather. If working outdoors in sunshine cannot be avoided, then adequate sun protection must be supplied and worn, including appropriate clothing, hats, sunglasses and sunscreen. Image by Mason Dahl on Unsplash When working on speci c tasks outside in the weather, be conscious of weather conditions 2023-01-12 B-09 Human Factors Page 201 of 340 CASA Part 66 - Training Materials Only  Training and Personal Protective Equipment (PPE) Employers have an obligation to ensure that staff are adequately trained and supported when they carry out potentially dangerous tasks associated with their job function. Part of this support is the provision of Personal Protective Equipment (PPE) of the types mentioned in these notes. For example, they may need: Hearing protection Breathing equipment and masks Protective clothing such as overalls and safety boots, and clothing for weather conditions, such as wet weather gear, waterproof boots, cold weather jackets, gloves and pants, caps, hard hats and sunglasses Protective substances such as sunscreen Ancillary equipment and tooling such as safe sources of illumination. USAF Little Rock Air Force Base Employers have an obligation to ensure that staff are adequately trained and supported when they carry out potentially dangerous tasks 2023-01-12 B-09 Human Factors Page 202 of 340 CASA Part 66 - Training Materials Only