Dynamical aspects of fragmentation

In this short communication we address the problem of reducibility in a highly excited Lennard-Jones system. We show that the probability of emitting $n$ fragments can be described in terms of a single probability through the binomial expression. However, the Arrhenius law does not hold and the process can be viewed as a mixture of sequential and simultaneous fragmentation events.Comment: Proceedings for VI Latin American Symposium on Nuclear Physics and Applications, Iguazu, Argentina (2005). To be published in Acta Phys. Hung.

Dynamical properties of constrained drops

In this communication we analyze the behavior of excited drops contained in spherical volumes. We study different properties of the dynamical systems i.e. the maximum Lyapunov exponent MLE, the asymptotic distance in momentum space $d_{\infty}$ andthe normalized variance of the maximum fragment NVM. It is shown that the constrained systems behaves as undergoing a first order phase transition at low densities while as a second order one at high densities. The transition from liquid-like to vapor-like behavior is signaled both by the caloric curves, thermal response functions and the MLE. The relationship between $MLE,d_{\infty}$, and the CC is explored.Comment: 7 pages, 9 figures in a two column forma

Teaching the Next Generation of Researchers: An Inquiry into Aviation Research Education

Research in aviation fields has become increasingly important to institutions and their faculty. Expectations to conduct such research have escalated with tenure and employment decisions often hanging on evidence of research skill and advanced educational attainment. Considering the importance of research to aviation higher education, this study investigated how research skills are conveyed to undergraduate and graduate aviation students. Further, the subjects and methods of instruction were evaluated. This inquiry was guided by content analysis. To bolster the findings of this study, a series of interviews with program directors and faculty teaching research courses were conducted to explore faculty perceptions on research education as well the as strengths and weaknesses of such education and the students enrolled in research courses. Keywords: research, education, aviation, content analysis, interviews, research-lead educatio

Public Opinion Concerning the Siting of Vertiports

This study sought a better understanding of public opinion about the siting of vertiports to support Advanced Air Mobility (AAM). An online survey was used to collect the necessary data. The survey was divided into seven sections: personal impacts, community impacts, acceptable proximity, benefits and concerns, flight operations, open-ended comments, and demographics. The findings for personal impacts suggested a slightly positive outlook. Community impacts were assessed, and data also indicated a marginally positive outlook. The survey revealed that a tolerable average distance between the home of the respondent and a vertiport was between one to two miles. Opinions about the benefits of a vertiport were found to include saving time, access to transit, reduced congestion, flexibility, and economic impact. Respondent concerns focused on safety, noise, air pollution, light pollution, and visual distractions/disturbances. The majority of respondents indicated that 35-40 daily flights would be acceptable. The survey also revealed that respondents were mostly comfortable with the proximity of eVTOLs to their homes but preferred that eVTOLs were flying at an altitude of 1,000 feet or higher. The demographics of respondents were also outlined. The results of this study provide planners and stakeholders with critical information necessary to consider public concerns and community impacts when selecting sites for vertiports

Analysis of Runway Incursion Trends: Implications for Cost-Benefit Analysis of Mitigation Investments

This causal-comparative and correlation study investigated the costs of runway incursion safety improvements in relation to their effectiveness to assess potential aviation system benefits.Two airports (Los Angeles International and Dallas-Ft. Worth International), which were early adopters of Runway Status Lights (RWSL), a runway incursion technology, were targeted in this analysis. Findings indicated that there were no significant differences in counts or rates of Category A, B, and D incursions at LAX and DFW when comparing the time periods before versus after RWSL installation. Category C counts and rates were found to have increased significantly after RWSL installation. The findings of this study outline the importance of assessing empirically-based impacts of large investments in aviation safety prior to implementing them system-wide. The findings do not support the premise that RWSL has improved safety at either LAX or DFW airports. Suggestions for future research are also outlined

Taking Flight or Taking a Pass? Exploring Factors Influencing Consumer Willingness to Pay for eVTOL Travel

The Advanced Air Mobility (AAM) industry is experiencing significant growth due to technological advancements and increasing demand for efficient travel experiences. The market is expected to reach $45 billion by 2030, with major players like Joby, Archer, Beta, and Wisk dominating. This study aimed to assess public willingness to pay for AAM services using eVTOLs, using Amazon\u27s Mechanical Turk platform. The survey yielded a response rate of 85.8%, with 1,622 completed surveys. The study found that younger urban consumers were more willing to pay higher prices for AAM electric vertical takeoff and landing (eVTOL) aircraft trips than older participants, possibly due to their tech-savvy nature and openness to new transportation technologies. Age, income, and race showed minimally influenced willingness to pay (WTP) at higher price points, but age and marital status had some influence at lower price points. Income level did not significantly affect willingness to pay more for eVTOL services, suggesting that this mode of transportation may be palatable to a wide range of consumers regardless of their financial situation. A well-rounded approach that considers pricing, advantages, safety features, environmental impact, accessibility, and partnerships will be crucial for companies to succeed in the rapidly growing eVTOL market. Findings show that by targeting younger, married, middle-class urbanites, AAM providers could tap into a lucrative market segment and increase adoption and profitability in the emerging mode of transportation. Suggestions for future research are also provided

Development and Validation of an Aviation Research Survey

Surveys are one of the more commonly utilized data collection instruments in aviation research. Unfortunately, there often is little information provided as to how the surveys utilized in such studies were developed. This is problematic because the validity and construction of surveys are critical to the successful collection of data. Further, without the proper distribution methodologies in place, survey response rates can be poor. This qualitative study provides a literature-based process to assist aviation researchers to design and validate a survey instrument. First a literature-based survey development protocol was developed. Next, a validation process utilizing a panel of experts was created. Panel members were sought with experience and qualifications specific to the subject areas covered in the survey including its (a) construction, (b) implementation, (c) graduate level research, (d) higher education, (e) aviation higher education, (f) the aviation industry, (g) flight instruction and certification, and (h) demographic measures. Interviews were conducted each of the five expert panel members using a semi-structured protocol. The results of the interviews were coded using NVivo qualitative analysis software. The panel members determined that the example survey was a valid instrument to use in an applicable study. A summary of panel member feedback that could be generalized to a wide range of aviation surveys is provided. In summary, through a careful review of available literature and through the conduct of a panel of experts review, an explicit, structured process was fashioned for aviation researchers to use in order to successfully create and validate a survey instrument for use in a variety of studies

A Quantitative Analysis of Seaplane Accidents from 1982-2021

This study aimed to assess and analyze all historical National Transportation Safety Board accident reports since 1982. For analysis, reports were bisected into seaplane (float, amphibian, and hull) and non-seaplane groups. Findings showed that there is a deficiency in the level of available detail on the seaplane fleet and cadre of seaplane pilots in the U.S. During the most recent ten years of complete data (2012-2021) showed a negative trend in all accidents and fatal accidents, although only the latter being statistically convincing. During this timeframe, seaplane accident pilots had significantly higher total time and age than other groups (non-seaplane accident and non-accident). Although practically (not statistically) significant, seaplane accident pilots had significantly more flight time in type than non-seaplane accident pilots. In both periods, the top accidents were de Havilland, Cessna, and Piper. Accident event sequences showed higher numbers of accidents during takeoffs among seaplanes. A comparison of the estimated seaplane accident rate per 100,000 hours vs. that of non-seaplanes was found not to be significantly different. This provides further evidence that the assumption that seaplanes are involved in more accidents is simply anecdotal, although more research is required for a conclusive answer. Between 1982 and 2021, considerable gains in seaplane safety were noted, with decreases in both total and fatal accidents. From this larger dataset, an assessment of seaplane and non-seaplane accident pilot time in type showed that seaplane pilots have significantly lower hours. The top aircraft makes were virtually unchanged across timeframes, with the top slots still going to de Havilland, Cessna, and Piper. In summary, while seaplane operations have consistently become safer over time, specific areas continue to cause an unacceptable loss of aircraft and lives. The findings of this study will hopefully help guide efforts to continue to improve seaplane safety and provide critical insights for the seaplane pilot community