Hazards and Mitigation Measures in Aerospace Non-Destructive Testing

As an aircraft component is subjected to tensile/torsional/bending forces and heat cycles during operation, non-destructive inspection programs have been mandated by aviation regulatory authorities and component manufacturers to ensure that cracks and flaws in the aircraft structure, engine and components are detected before reaching catastrophic failure modes. In aerospace settings, eddy current, magnetic particle, dye penetrant and radiography inspection methods are known to affect worker health. Two recent studies have linked dye chemicals to bladder cancer, excessive electromagnetic field exposure has been linked to undue stress on the human body, and excessive exposure to ionizing radiation has been linked to cancer. The electromagnetic field magnitude levels (at respective frequencies) during eddy current and magnetic particle inspection processes must be within the established safety limits. Dye chemicals utilized in magnetic particle and dye penetrant testing must be kept away from contact or isolated through dilution and exhaust ventilation. Wireless imaging and data transfer technology and shielding should be used to minimize ionizing radiation during radiographic inspection. Ultrasonic testing is much less hazardous to human health when compared to radiographic, eddy current, magnetic particle and dye penetrant inspection methods, and passive infrared thermography devices pose no health hazards to workers in aerospace. As such, regulatory authorities and aircraft manufacturers should prescribe ultrasonic testing and passive thermographic inspections as the preferred non-destructive testing methods in the aviation field to mitigate the health hazards

UAS Maintenance: A Critical Component in Maintaining Airworthiness

Over the last several decades, the notion of traditional aircraft design has significantly changed. While there are many modern aircraft that resemble earlier models, their components, systems, and overall architecture have evolved, including the introduction of small unmanned aircraft systems (sUAS). Despite the growing consumer attraction to own and operate these aircraft, the subsequent impact on safety is an area of intense concern. The requirement of an established maintenance program for manned aircraft is rooted in ensuring that all aircraft are deemed safe for flight. Preventive maintenance schedules are based on component reliability data, which minimizes unnecessary maintenance while preventing maintenance-related aircraft accidents. This same requirement has not been extended to small unmanned aircraft systems. Current regulations and requirements for sUAS maintenance refer only to maintaining airworthiness, with no specific scheduled or unscheduled maintenance practices required. As the demand for small unmanned aircraft systems continues to grow, the safety threat will rise. The requirement of formal maintenance practices, which are based on component reliability data, would fulfill this need. To further explore the possibility of an established maintenance program for sUAS operators, this paper reviews current maintenance requirements and proposes new accident data collection measures which contribute to the creation of a scheduled maintenance program. A formal certification process which follows a modified MSG-3 process is also proposed

The Universality of Communication: Preparing the Next Generation of Aviation Professionals

Current aviation college programs aim to prepare the next generation of aviation professionals to meet the needs of the ever-increasing global demand for air travel. Previous literature has identified gaps in competencies that employers noted in young graduates. This study attempts to narrow that gap by focusing on the curriculum of the top 20 aviation programs in the U.S. to compare the curriculum to the skills employers cited to assess whether the courses offered in the current programs reflect the actual needs of the aviation workplace. From a survey of Aerospace and Defense (A&D) employers, ten skills were cited: Team player, negotiation skills, verbal/written/oral communication skills, problem solving, decision making, assertiveness, proactivity, and self-motivation. The skills are not job-specific and are universal, but most often are associated with business studies programs. Nonetheless, four of the top five skills from the A&D employers survey were communication centered skills. In a content analysis of the courses offered at the top 20 U.S. aviation programs, the number of communication courses ranged from zero to 14, with an overall average of 4.7 classes within the program. Business management programs presented a range of one to 29 communication courses, with an average of 12.5 classes in the course catalogue. Despite rigorous training in job-specific competencies, there is a lack of business acumen in young aviation professional graduates. By enrolling in many of the current programs, the students risk entering the workplace today without the necessary business based communication skills sought by the global aviation industr

UAS Maintenance: A Critical Component in Maintaining Airworthiness

Over the last several decades, the notion of traditional aircraft design has significantly changed. While there are many modern aircraft that resemble earlier models, their components, systems, and overall architecture have evolved, including the introduction of small unmanned aircraft systems. Despite the growing consumer attraction to own and operate these aircraft, the subsequent impact on safety is an area of intense concern. The requirement of an established maintenance program for manned aircraft is rooted in ensuring that all aircraft are deemed safe for flight. Preventive maintenance schedules are based on component reliability data, which minimizes unnecessary maintenance while preventing maintenance-related aircraft accidents. This same requirement has not been extended to small unmanned aircraft systems. Current regulations and requirements for sUAS maintenance refer only to maintaining airworthiness, with no specific scheduled or unscheduled maintenance practices required. As the demand for small unmanned aircraft systems continues to grow, the safety threat will rise. The requirement of formal maintenance practices, which are based on component reliability data, would fulfill this need. To further explore the possibility of an established maintenance program for sUAS operators, this paper reviewed current maintenance requirements and proposes new accident data collection measures which contribute to the creation of a scheduled maintenance program. A formal certification process which follows a modified MSG-3 process is also proposed

From Sensors to Knowledge: The Challenge of Training the Next Generation of Data Analysts

With the advent of commercial-off-the-shelf sensors for use in a variety of applications, integration with analytical software tools, and expansion of available archived datasets, there is a critical need to address the problem of transforming resultant data into comprehensible, actionable information for decision-makers through rigorous analysis. In previous research the participating authors have emphasized that users are often faced with the situation in which they are “drowning in a sea of data” but still “thirsting for knowledge”. The availability of analysis software, tools, and techniques provide opportunities for information collection of ever increasing complexity, but the need for the training of analysts to employ appropriate tools and processes to ensure accurate and applicable results has not been addressed. The purpose of this paper is to discuss the challenges and opportunities facing the training of effective analysts capable of handling a wide-range of data types in this era of dynamic tools and techniques

Effect of the N-based ligands in copper complexes for depolymerisation of lignin

Several organic soluble N-based ligands and their copper complexes were firstly investigated as catalysts to depolymerise organosolv lignin in the organic solvent, dimethylformamide (DMF) and an ionic liquid (1-ethyl-3-methylimidazolium xylenesulfonate, [emim][ABS]). The results of screening depolymerisation reactions in DMF and [emim][ABS] showed that all the copper–amine complexes catalysed lignin depolymerisation more efficiently in ionic liquids than in DMF. Among the seven types of ligands, copper complexes with two types of ligands (E)-N-(pyridin-2-ylmethylene)aniline and (E)-4-methoxy-N-(pyridin-2-ylmethylene)aniline depolymerised the lignin more efficiently than the others. These two copper complexes with the N-based ligand were further studied to determine the most efficient conditions for the depolymerisation of the lignin. The most effective depolymerisation by conditions involved treatment at 180 °C for 12 h in [emim][ABS]. Cyclic voltammetric studies were carried out to investigate the reversible potential associated with the copper centers of their complexes with these N-based ligands. The results suggest that two types of ligands have more positive reversible potentials than those of other copper complexes

Viability and Application of Mounting Personal PID VOC Sensors to Small Unmanned Aircraft Systems

Using a UAS-mounted sensor to allow for a rapid response to areas that may be difficult to reach or potentially dangerous to human health can increase the situational awareness of first responders of an aircraft crash site through the remote detection, identification, and quantification of airborne hazardous materials. The primary purpose of this research was to evaluate the remote sensing viability and application of integrating existing commercial-off-the-shelf (COTS) sensors with small unmanned aircraft system (UAS) technology to detect potentially hazardous airborne contaminants in emergency leak or spill response situations. By mounting the personal photoionization detector (PID) with volatile organic compound VOC sensor technology on UAS platforms, the needed information may be obtained at an optimum range and resolution without needlessly exposing a human to possible adverse conditions

In vitro cytotoxicity of Manville Code 100 glass fibers: Effect of fiber length on human alveolar macrophages

BACKGROUND: Synthetic vitreous fibers (SVFs) are inorganic noncrystalline materials widely used in residential and industrial settings for insulation, filtration, and reinforcement purposes. SVFs conventionally include three major categories: fibrous glass, rock/slag/stone (mineral) wool, and ceramic fibers. Previous in vitro studies from our laboratory demonstrated length-dependent cytotoxic effects of glass fibers on rat alveolar macrophages which were possibly associated with incomplete phagocytosis of fibers ≥ 17 μm in length. The purpose of this study was to examine the influence of fiber length on primary human alveolar macrophages, which are larger in diameter than rat macrophages, using length-classified Manville Code 100 glass fibers (8, 10, 16, and 20 μm). It was hypothesized that complete engulfment of fibers by human alveolar macrophages could decrease fiber cytotoxicity; i.e. shorter fibers that can be completely engulfed might not be as cytotoxic as longer fibers. Human alveolar macrophages, obtained by segmental bronchoalveolar lavage of healthy, non-smoking volunteers, were treated with three different concentrations (determined by fiber number) of the sized fibers in vitro. Cytotoxicity was assessed by monitoring cytosolic lactate dehydrogenase release and loss of function as indicated by a decrease in zymosan-stimulated chemiluminescence. RESULTS: Microscopic analysis indicated that human alveolar macrophages completely engulfed glass fibers of the 20 μm length. All fiber length fractions tested exhibited equal cytotoxicity on a per fiber basis, i.e. increasing lactate dehydrogenase and decreasing chemiluminescence in the same concentration-dependent fashion. CONCLUSION: The data suggest that due to the larger diameter of human alveolar macrophages, compared to rat alveolar macrophages, complete phagocytosis of longer fibers can occur with the human cells. Neither incomplete phagocytosis nor length-dependent toxicity was observed in fiber-exposed human macrophage cultures. In contrast, rat macrophages exhibited both incomplete phagocytosis of long fibers and length-dependent toxicity. The results of the human and rat cell studies suggest that incomplete engulfment may enhance cytotoxicity of fiber glass. However, the possibility should not be ruled out that differences between human versus rat macrophages other than cell diameter could account for differences in fiber effects

Deweyan tools for inquiry and the epistemological context of critical pedagogy

This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated