<p>Composite materials used in the aviation industry are known to be more complex than their metallic predecessors. This impacts not only the design and manufacturing of composite structures, but also the failure studies when these structures fail and break (as may be the case in an aircraft accident). Additionally, when under combustion, composite materials introduce potential health hazards. At elevated temperatures, the fibers can be released, presenting an inhalation hazard. Similarly, the matrix decomposition results in a series of potentially toxic byproducts. When encountering composite fires at aircraft accident sites, a series of protocols have been delineated by the corresponding agencies. These include wearing personal protective equipment as well as the application of so-called fixant solutions over the burning composites, with the latter being the focus of this study. The purpose of the fixant solutions is to provide a film of protection that – in essence – holds down small fibers and prevents them from becoming airborne. While the use of fixant solutions is necessary to protect the health of individuals in the vicinity of burnt composites, the potential detrimental impact the application thereof has on fractographic evidence should also be considered. Experts in the field have voiced concerns regarding the use of fixants, outlining that these chemicals may wash evidence away, cover up evidence, or interfere with imaging methods needed during the failure analysis. The purpose of the conducted research, thus, was to compare the relative impact of four commonly used fixant solutions – namely water, wetted water, polyacrylic acid (PAA), as well as a mixture of water and floor wax – on fractographic features of failed carbon fiber/epoxy composite specimens. Specifically, fractographic evidence of two forms of damage – impact and tension – were evaluated. With this goal, the methodology included steps to manufacture the specimens of interest, introduce the two forms of damage, burn the specimens, apply fixants, and perform the microscopic analysis via a scanning electron microscope (SEM). The fractographic evidence prior and after the application of fixant was evaluated qualitatively and quantitatively. The results showed that the evaluated fixants did influence the fracture surfaces imaged, and in certain cased obscured evidence of interest. Additionally, differences between the fixants were ascertained for both forms of damage evaluated. The water treatment was found to perform the best, minimizing the disruption of evidence. Nonetheless, while the study did answer the research questions and the different treatments were compared, additional areas of research and factors that should be considered were identified. </p>

There are many pieces of flight deck research on general use of written English language technical information and problem solving using technical documentation. Contributory causes of aircraft accidents have been due to misunderstandings of crew alerts and procedural divergence by English as-a-second language flight crewmembers (ESL). Research was conducted to understand impact of written English language technical information on ESL flight crewmembers’ performance. Two types of systems were evaluated, technical documentation and crew alerting systems that contain technical information, with respect to their impact on ESL flight crewmember performance. Preliminary analysis results indicated written English language technical information can be confusing, difficult to read and interpret, and leads to misunderstandings by ESL flight crewmembers during aircraft nonnormal conditions. English as-a-second language flight crewmembers indicated they often experience problems executing written English language technical procedures after outset of crew alerts. Conversely, experimental trials revealed ESL flight crewmembers did not experience many cognitive performance issues with use of crew alerting systems and technical information designed with an English language emphasis. English as-a second language flight crewmembers’ English language proficiency, background knowledge, and use of use of metacognitive strategies to read and comprehend written English language on crew alerting and information systems, indicated they utilized written English technical information with ease. Particularly, ESL flight crewmembers’ workload was low, they had fast response times to system faults, and they experienced minimal procedural deviations. On the contrary, when ESL flight crewmembers utilized written English language technical procedures translated into their native language during non-normal conditions, they experienced several cognitive performance challenges. English as-a second language flight crewmembers’ background knowledge of written English language technical information translated into their native language, use of metacognitive strategies to read and comprehend written English language translated into their native language, indicated they experienced difficulties with reading and comprehending translated technical information on information systems. Particularly, ESL flight crewmembers were challenged cognitively when they responded to crew alerts through execution of decision-making processes. They indicated translation of written English language technical information into their native language was a pre-cursor to procedural deviation, long response times to system issues, as well as high workload during experimental trials. It is recommended that further research focus on design and use of written English language technical documentation by ESL flight crewmembers during non-normal conditions. It is also recommended that if deemed practical by the aviation industry, further research should focus on design, integration, and utilization of technical documentation in a language(s) other than English, and measurement of ESL flight crewmembers performance on the flight deck.

There are many pieces of flight deck research on general use of written English language technical information and problem solving using technical documentation. Contributory causes of aircraft accidents have been due to misunderstandings of crew alerts and procedural divergence by English as-a-second language flight crewmembers (ESL). Research was conducted to understand impact of written English language technical information on ESL flight crewmembers’ performance. Two types of systems were evaluated, technical documentation and crew alerting systems that contain technical information, with respect to their impact on ESL flight crewmember performance. Preliminary analysis results indicated written English language technical information can be confusing, difficult to read and interpret, and leads to misunderstandings by ESL flight crewmembers during aircraft nonnormal conditions. English as-a-second language flight crewmembers indicated they often experience problems executing written English language technical procedures after outset of crew alerts. Conversely, experimental trials revealed ESL flight crewmembers did not experience many cognitive performance issues with use of crew alerting systems and technical information designed with an English language emphasis. English as-a second language flight crewmembers’ English language proficiency, background knowledge, and use of use of metacognitive strategies to read and comprehend written English language on crew alerting and information systems, indicated they utilized written English technical information with ease. Particularly, ESL flight crewmembers’ workload was low, they had fast response times to system faults, and they experienced minimal procedural deviations. On the contrary, when ESL flight crewmembers utilized written English language technical procedures translated into their native language during non-normal conditions, they experienced several cognitive performance challenges. English as-a second language flight crewmembers’ background knowledge of written English language technical information translated into their native language, use of metacognitive strategies to read and comprehend written English language translated into their native language, indicated they experienced difficulties with reading and comprehending translated technical information on information systems. Particularly, ESL flight crewmembers were challenged cognitively when they responded to crew alerts through execution of decision-making processes. They indicated translation of written English language technical information into their native language was a pre-cursor to procedural deviation, long response times to system issues, as well as high workload during experimental trials. It is recommended that further research focus on design and use of written English language technical documentation by ESL flight crewmembers during non-normal conditions. It is also recommended that if deemed practical by the aviation industry, further research should focus on design, integration, and utilization of technical documentation in a language(s) other than English, and measurement of ESL flight crewmembers performance on the flight deck.