Effect of Vaccination on Risk of Exposure to Airborne Infectious Disease During the Boarding Process in a Commercial Aircraft Using Agent-Based Simulation

As increasing proportions of the world's population have received at least one dose of the vaccine against COVID-19, everyday activities start to be resumed, including travels. The present study investigates the impact of immunization on the risk of exposure to an infectious disease such as COVID-19, during the boarding process in a commercial airplane. An agent-based simulation model considers different vaccine types and vaccination rates among passengers. The results show significant decrease in the median exposure risk, when the vaccination rate increases from 0% to 100%, but also that people in seats adjacent to an infectious passenger are in much higher risk, for a similar vaccination coverage. Such results provide quantitative evidence of the importance of mass immunization, and also that, when full vaccination is not guaranteed for 100% of passengers, it may be recommendable to avoid full occupancy of the aircraft, by implementing physical distancing when assigning seats. © 2022 IEEE.

Air Distribution System for Infection Reduction in Commercial Airplane Premium Economy and Business Class Passenger Seats

In previous works made by the authors, a new air distribution system with Personalized Ventilation (PV) combined with Underfloor Air Distribution (UFAD) has been proposed. The proposed system in four different configurations provided thermal comfort, as well as a shield between passengers for infection reduction in economy class seats in an airplane. This work extends the previous works by studying the same system for premium economy and business class seats which have extra spacing between passengers. The proposed system provided enhanced thermal comfort despite the extra spacing of the seats. The Predictive Mean Vote (PMV) has recorded the best value of 0.38 for the business class seats compared to all the other seating configurations. Predicted Percentage Dissatisfied (PPD) has also been improved with values of 12.2% and 10.9% for the premium economy and business classes respectively. In addition to thermal comfort, the proposed system still provides an adequate air shield for passengers in the widely spaced premium economy and business classes. It is recommended as an alternative to the conventional mixed ventilation system in a commercial airplane for all seating plans. © 2022 Praise Worthy Prize S.r.l. All rights reserved.

Airplane Boarding Methods that Reduce Risk from COVID-19.

Airlines have recently instituted practices to reduce the risk of their passengers becoming infected with the novel coronavirus (SARS-CoV-2). Some airlines block their airplanes' middle seats to preserve social distancing among seated passengers. In this context, we present six new boarding methods and compare their performance with that of the two best boarding methods used to date with social distancing. We evaluate the eight boarding methods using three performance metrics related to passenger health and one operational metric (airplane boarding time) for a one-door airplane. The three health metrics reflect the risks of virus spread by passengers through the air and surfaces (e.g. headrests and seat arms) and consider the amount of aisle social distancing between adjacent boarding passengers walking towards their seats. For an airline that highly values the avoidance of window seat risk, the best method to use is one of the new methods: back-to-front by row - WilMA, though it will result in a longer time to complete boarding of the airplane. Airlines placing greater emphasis on fast boarding times- while still providing favorable values for the health metrics-will be best served by using new methods back-to-front by row - WilMA - offset 2 and - offset 3 when aisle social distancing is 1 m and 2 m respectively.

Grey Clustering of the Variations in Reverse Pyramid Boarding Method Considering Pandemic Restrictions

The COVID-19 pandemic has significantly hit the airline industry mostly due to the reduced number of flights between regions, the implementation of different protocols, restrictions, and the reluctance of the passengers to travel by airplane. In this context, the airlines have tried to offer an appropriate environment for their customers by ensuring a safe boarding process while considering the imposed restrictions related to social distancing. According to the literature, the Reverse Pyramid boarding method offers superior results in terms of boarding time and health risks in times of pandemics when compared to other classical airplane boarding methods. As the variations in Reverse Pyramid implementation are numerous, the present paper aims to determine which of these variations can be used when the airplane boarding process is made through the front door of the airplane. For this purpose, an agent-based model is created and used for simulating the variations in the Reverse Pyramid boarding method, while grey clustering is applied for dividing the variations into categories based on their performance. Three performance indicators, as reported in the scientific literature related to airplane boarding in times of COVID-19, are used, namely the boarding time, aisle seat risk, and window seat risk. Different scenarios are presented and analyzed in depth.

An Improved Air Distribution System for Infection Reduction in Economy-Class Passenger Airplanes

In a previous work performed by the authors, a Personalized Ventilation (PV) system, combined with Under Floor Air Distribution (UFAD) has been found to provide an air shield between passengers in an airplane and reduce the chances of viruses spreading. A new PV system with a front-back design has been adopted. Combined with UFAD, the new system has achieved thermal comfort for the passengers, as well as a reduction of contaminants spreading. However, the PV system can be further improved by changing the air inlet and outlet configurations. In this work, two new PV system configurations are investigated with changed locations of the air outlets. In addition to an improved air shield between passengers and hence better infection reduction, the new configurations have also improved the predictive mean vote to the value of 0.51, and the predicted percentage dissatisfied to 13.9%. © 2022 Praise Worthy Prize S.r.l.

Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission Among Air Passengers in China.

BACKGROUND: Modern transportation plays a key role in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and new variants. However, little is known about the exact transmission risk of the virus on airplanes. METHODS: Using the itinerary and epidemiological data of coronavirus disease 2019 (COVID-19) cases and close contacts on domestic airplanes departing from Wuhan city in China before the lockdown on 23 January 2020, we estimated the upper and lower bounds of overall transmission risk of COVID-19 among travelers. RESULTS: In total, 175 index cases were identified among 5797 passengers on 177 airplanes. The upper and lower attack rates (ARs) of a seat were 0.60% (34/5622, 95% confidence interval [CI] .43-.84%) and 0.33% (18/5400, 95% CI .21-.53%), respectively. In the upper- and lower-bound risk estimates, each index case infected 0.19 (SD 0.45) and 0.10 (SD 0.32) cases, respectively. The seats immediately adjacent to the index cases had an AR of 9.2% (95% CI 5.7-14.4%), with a relative risk 27.8 (95% CI 14.4-53.7) compared to other seats in the upper limit estimation. The middle seat had the highest AR (0.7%, 95% CI .4%-1.2%). The upper-bound AR increased from 0.7% (95% CI 0.5%-1.0%) to 1.2% (95% CI .4-3.3%) when the co-travel time increased from 2.0 hours to 3.3 hours. CONCLUSIONS: The ARs among travelers varied by seat distance from the index case and joint travel time, but the variation was not significant between the types of aircraft. The overall risk of SARS-CoV-2 transmission during domestic travel on planes was relatively low. These findings can improve our understanding of COVID-19 spread during travel and inform response efforts in the pandemic.

Optimization of Aircraft Taxiing Strategies to Reduce the Impacts of Landing and Take-Off Cycle at Airports

The increasing attention of opinion towards climate change has prompted public authorities to provide plans for the containment of emissions to reduce the environmental impact of human activities. The transport sector is one of the main ones responsible for greenhouse emissions and is under investigation to counter its burdens. Therefore, it is essential to identify a strategy that allows for reducing the environmental impact produced by aircraft on the landing and take-off cycle and its operating costs. In this study, four different taxiing strategies are implemented in an existing Italian airport. The results show advantageous scenarios through single-engine taxiing, reduced taxi time through improved surface traffic management, and onboard systems. On the other hand, operating towing solutions with internal combustion cause excessive production of pollutants, especially HC, CO, NOX, and particulate matter. Finally, towing with an electrically powered external vehicle provides good results for pollutants and the maximum reduction in fuel consumption, but it implies externalities on taxiing time. Compared to the current conditions, the best solutions ensure significant reductions in pollutants throughout the landing and take-off cycle (−3.2% for NOx and −44.2% for HC) and economic savings (−13.4% of fuel consumption).

Hiding from the drug screen: a case of extensive nitrous oxide misuse

Objective: To describe a case of extensive nitrous oxide (NO) misuse in a commercial airline pilot to specifically avoid detection on employer urine drug screens (UDS). Case report: A 48-year-old male commercial airline pilot was evaluated in a Medical Toxicology clinic for history of NO misuse. He started using NO and cannabis as a teenager. When he became an airline pilot, he stopped his cannabis use to ensure he passed frequent employer drug screens. He researched that NO was not detected on UDS and continued its use. During the COVID-19 pandemic, the patient's use grew to 1,200 eight gram NO canisters daily in an attempt to alleviate his stress. He described inhaling the gas until he passed-out. Upon waking, he, would use more until he again passed-out, repetitively cycling throughout the night. His developed paresthesias, progressive weakness in legs, and difficulty walking to the point where he had to crawl to the front door to receive his shipments of NO canisters. His cognition declined and he was brought to the hospital for help after being found in his home garage. Magnetic resonance imaging (MRI) imaging of the brain showed atrophy from chronic toxic metabolic encephalopathy. MRI of the spine did not show abnormalities. Upon referral to the Medical Toxicology clinic, he had not used NO for 3 months and had been taking vitamin B172. Symptoms had improved, but he still had extremity paresthesias, memory difficulties, and required a cane to walk. The patient's NO misuse had been reported to the Federal Aviation Administration (FAA) during his hospitalization and he was no longer allowed to pilot commercial airlines. Conclusion: Random drug testing of airline pilots is required by the FAA and the UDS test for D-9-tetrahydrocannabinol-9-carboxylic acid, benzoylecgonine, codeine, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone, 6-acetylmorphine, phencyclidine, amphetamine, methamphetamine, methylenedioxymethamphetamine and methylenedioxyamphetamine [1]. Negative drug screens may give an employer a false sense of security that a pilot is not using/misusing substances but the UDS does not pick up numerous abused substances, including inhalants. This case illustrates the dangers in relying solely on the UDS to ensure pilots are clear from illicit substances. This patient was misusing nitrous oxide for decades which lead to permanent cognitive decline that negatively impacted his ability to safely fly.

Genomic Evidence of In-Flight SARS-CoV-2 Transmission, India to Australia, April 2021.

Epidemiologic and genomic investigation of SARS-CoV-2 infections associated with 2 repatriation flights from India to Australia in April 2021 indicated that 4 passengers transmitted SARS-CoV-2 to >11 other passengers. Results suggest transmission despite mandatory mask use and predeparture testing. For subsequent flights, predeparture quarantine and expanded predeparture testing were implemented.

Sustainable Development Programming of Airports by Identification of Non-Efficient Units

This article concerns the identification of inefficient airports and the exploration of spatial autocorrelation for programming sustainable development. The first research question was: do domestic airports cooperate by shifting passenger service and traffic to the geographically closest airport to respect the idea of sustainable development (in view of the rationalization of energy consumption)? The second question was: do they excessively compete for passengers and the carriers serving them? The aim was to identify ineffective units (taking into account energy consumption, airplane traffic, and passenger movement) and to evaluate the spatial autocorrelation between national airports, which shows whether airports cooperate or compete with each other. The study was conducted on 12 airports. An innovative extension of the data envelopment analysis method using methods in the field of spatial econometrics (including two-dimensional Moran I statistics and local LISA statistics) and artificial intelligence was applied. It was verified that ineffective airports have a non-rationalized structure of inputs to outputs. Based on the map-graph of connections, airports have been identified to which part of airplane traffic service can be transferred. Based on Moran statistics and local LISA statistics, it was confirmed that airports compete with each other. There was a strong polarization of efficient airports.

COVID-19 as an Occupational Illness: An International Comparison of Recognition Regulation in Selected Countries

Introduction: The COVID-19 pandemic has changed the practices of occupational health in many aspects. Due to heavy caseloads, the traditional approach of contact tracing may not be implemented comprehensively, impeding the determination of causality of workplace exposure on COVID-19. The current study examines measures adopted by selected countries for recognizing work-related COVID-19. Material and Methods: Regulation and rules of recognition of work-related COVID-19 in various countries were obtained through a systematic review of published literature and official government websites. The US, France, Germany, South Korea, Taiwan were among the fifty countries included in the comparative analysis. Data on approved and total claims cases were obtained through open data of national Workers’ Compensation systems and analyzed by types of regulation. Results: Some countries stuck to the case-by-case investigation of causality, while others introduced unique measures, including the rebuttable presumption of compensability. In the latter cases, the work-relatedness of patients from certain high-risk occupations was automatically recognized unless the dominant evidence proved the contrary. As with traditional understandings, health care professionals and first responders were defined as high-risk in most presumption rules. However, in the context of substantial community transmission, occupations with frequent public contact, like aircrews, customs personnel, and store clerks, were also included in some countries. Conclusions: The presumption rules had an active role in facilitating the compensation of work-related COVID-19.

Aviation's Aerotoxic Syndrome in a post pandemic world

Introduction: While there is strong interest in aircraft air quality in respect to COVID-19 and emissions into the environment, the concerns regarding oils and hydraulic fluids leaking into the aircraft air supply and cabin have yet to receive the same level of attention. This is despite considerable knowledge about this design problem first recognised in the late 1930s. Materials and Methods: A brief review of what we know, and the various current activities related to aircraft bleed air contamination will be undertaken in order to determine what are and why it may be necessary to implement various mitigation strategies. Results: Aircrew, aviation workers and passengers are exposed to low levels of engine oils and hydraulic fluids on a regular basis in normal flight. There have been considerable initiatives over the past two decades exploring this topic and assessing if there is a need and what steps may be undertaken to mitigate the risk of exposing aircrew and passengers to particles and contaminants that enter the air supply either in normal operations or during a failure event. The aviation industry has not given the same attention to bleed air contamination of the air supply as it has to contamination due to COVID-19 and emissions into the outside environment. Conclusions: Aircrew and passengers are exposed to low levels of ultrafine particles and chemical compounds that enter the aircraft breathing air supply in normal operations, which require a range of risk mitigation strategies to be undertaken.

An Alternative Air Distribution System in Economy-Class Passenger Airplane for Infection Reduction

– Airplane transportation has played a major role in the spread of the new corona virus COVID-19 all over the world. The current air distribution system used in airplanes circulation assists motion of contaminants and hence spreads airborne diseases. In this work, a new air distribution system is proposed. A combined Under Floor Air Distribution (UFAD) and a new Personalized Ventilation (PV) systems with a front-back design has been adopted such that it satisfies thermal comfort for the passengers, as well as providing an air shield between the passengers in order to prevent the spread of airborne contaminants. Two configurations have been made for the economy class in a passenger airplane. Both had the same UFAD system, and PV system with air inlet located at the back of the ahead seat, but with different air inlet angles, normal to the seat back and inclined by 45°. It has been found out that the second configuration provides better control for contaminant spreading, as well as better thermal comfort, with predictive mean vote of 0.6, and predicted percentage dissatisfied of 17.6%. © 2021 Praise Worthy Prize S.r.l.-All rights reserved.

Grey clustering of the variations in the back-to-front airplane boarding method considering COVID-19 flying restrictions

PurposeThe airline industry has been significantly hit by the occurrence of the new coronavirus SARS-CoV-2, facing one of its worst crises in history. In this context, the present paper analyses one of the well-known boarding methods used in practice by the airlines before and during the coronavirus outbreak, namely back-to-front and suggests which variations of this method to use when three passenger boarding groups are considered and a jet bridge connects the airport terminal with the airplane.Design/methodology/approachBased on the importance accorded by the airlines to operational performance, health risks, and passengers' comfort, the variations in three passenger groups back-to-front boarding are divided into three clusters using the grey clustering approach offered by the grey systems theory.FindingsHaving the clusters based on the selected metrics and considering the social distance among the passengers, airlines can better understand how the variations in back-to-front perform in the new conditions imposed by the novel coronavirus and choose the boarding approach that better fits its policy and goals.Originality/valueThe paper combines the advantages offered by grey clustering and agent-based modelling for offering to determine which are the best configurations that offer a reduced boarding time, while accounting for reduced passengers' health risk, measured through three indicators: aisle risk, seat risk and type-3 seat interferences and for an increased comfort for the passengers manifested through a continuous walking flow while boarding.

Social distancing in airplane seat assignments for passenger groups

We provide a mixed-integer programming model (MIP) to assign airplane passengers to seats while preserving two types of social distancing: the distance from the passengers' seats to the aisle and the distance among groups of passengers who are not travelling together. The method assigns passengers travelling within a family group to seats near others of the same group. We present a heuristic algorithm to solve the proposed MIP. This algorithm is warm started with an initial seat assignment. Stochastic simulation experiments using the new method confirm that more passengers can be assigned safely to the seats when family groups are considered. For a certain load of passengers, as the percentage of family groups compared to singleton passengers increases, the model can practice social distancing among more passengers from different groups. The proposed model provides a superior seating assignment compared to an airline policy of blocking all middle-seats.

Evaluation of Boarding Methods Adapted for Social Distancing When Using Apron Buses.

Social distancing reduces the risk of people becoming infected with the novel coronavirus (SARS-CoV-2). When passengers are transported from an airport terminal to an airplane using apron buses, safe social distancing during pandemic times reduces the capacity of the apron buses and has led to the practice of airlines keeping the middle seats of the airplanes unoccupied. This article adapts classical boarding methods so that they may be used with social distancing and apron buses. We conduct stochastic simulation experiments to assess nine adaptations of boarding methods according to four performance metrics. Three of the metrics are related to the risk of the virus spreading to passengers during boarding. The fourth metric is the time to complete boarding of the two-door airplane when apron bus transport passengers to the airplane. Our experiments assume that passengers advancing to their airplane seats are separated by an aisle social distance of 1 m or 2 m. Numerical results indicate that the three variations (adaptations) of the Reverse pyramid method are the best candidates for airlines to consider in this socially distanced context. The particular adaptation to use depends on an airline's relative preference for having short boarding times versus a reduced risk of later boarding passengers passing (and thereby possibly infecting) previously seated window seat passengers. If an airline considers the latter risk to be unimportant, then the Reverse pyramid - Spread method would be the best choice because it provides the fastest time to board the airplane and is tied for the best values for the other two health risk measures.

Seat Assignments With Physical Distancing in Single-Destination Public Transit Settings.

While the importance of physical (social) distancing in reducing the spread of COVID-19 has been well-documented, implementing similar controls in public transit remains an open question. For instance, in the United States, guidance for maximum seating capacity in single-destination public transit settings, such as school buses, is only dependent on the physical distance between passengers. In our estimation, the available models/guidance are suboptimal/inefficient since they do not account for the possibility of passengers being from the same household. This paper discusses and addresses the aforementioned limitation through two types of physical distancing models. First, a mixed-integer programming model is used to assign passengers to seats based on the reported configuration of the vehicle and desired physical distancing requirement. In the second model, we present a heuristic that allows for household grouping. Through several illustrative scenarios, we show that seating assignments can be generated in near real-time, and the household grouping heuristic increases the capacity of the transit vehicles (e.g., airplanes, school buses, and trains) without increasing the risk of infection. A running application and its source code are available to the public to facilitate adoption and to encourage enhancements.