Impact of different control policies for COVID-19 outbreak on the air transportation industry: A comparison between China, the U.S. and Singapore.

Many countries have been implementing various control measures with different strictness levels to prevent the coronavirus disease 2019 (COVID-19) from spreading. With the great reduction in human mobility and daily activities, considerable impacts have been imposed on the global air transportation industry. This study applies a hybrid SARIMA-based intervention model to measure the differences in the impacts of different control measures implemented in China, the U.S. and Singapore on air passenger and air freight traffic. To explore the effect of time span for the measures to be in force, two scenarios are invented, namely a long-term intervention and a short-term intervention, and predictions are made till the end of 2020 for all three countries under both scenarios. As a result, predictive patterns of the selected metrics for the three countries are rather different. China is predicted to have the mildest economic impact on the air transportation industry in this year in terms of air passenger revenue and air cargo traffic, provided that the control measures were prompt and effective. The U.S. would suffer from a far-reaching impact on the industry if the same control measures are maintained. More uncertainties are found for Singapore, as it is strongly associated with international travel demands. Suggestions are made for the three countries and the rest of the world on how to seek a balance between the strictness of control measures and the potential long-term industrial losses.

Data-Driven Estimation of the Impact of Diversions Due to In-Flight Medical Emergencies on Flight Delay and Aircraft Operating Costs.

INTRODUCTION: In-flight medical emergencies (IFMEs) average 1 of every 604 flights and are expected to increase as the population ages and air travel increases. Flight diversions, or the rerouting of a flight to an alternate destination, occur in 2 to 13% of IFME cases, but may or may not be necessary as determined after the fact. Estimating the effect of IFME diversions compared to nonmedical diversions can be expected to improve our understanding of their impact and allow for more appropriate decision making during IFMEs.METHODS: The current study matched multiple disparate datasets, including medical data, flight plan and track data, passenger statistics, and financial data. Chi-squared analysis and independent samples t-tests compared diversion delays and costs metrics between flights diverted for medical vs. nonmedical reasons. Data were restricted to domestic flights between 1/1/2018 and 6/30/2019.RESULTS: Over 70% of diverted flights recover (continue on to their intended destination after diverting); however, flights diverted due to IFMEs recover more often and more quickly than do flights diverted for nonmedical reasons. IFME diversions introduce less delay overall and cost less in terms of direct operating costs and passenger value of time (averaging around 38,000) than do flights diverted for nonmedical reasons.DISCUSSION: Flights diverted due to IFMEs appear to have less impact overall than do flights diverted for nonmedical reasons. However, the lack of information related to costs for nonrecovered flights and the decision factors involved during nonmedical diversions hinders our ability to offer further insights.Lewis BA, Gawron VJ, Esmaeilzadeh E, Mayer RH, Moreno-Hines F, Nerwich N, Alves PM. Data-driven estimation of the impact of diversions due to in-flight medical emergencies on flight delay and aircraft operating costs. Aerosp Med Hum Perform. 2021; 92(2):99105.

Stop Flying the Patients! Evaluation of the Overutilization of Helicopter Transport of Trauma Patients.

INTRODUCTION: Helicopter transport is a resource intensive and expensive method for transportation of patients by helicopter. The primary objective of this study was to evaluate the appropriateness of helicopter transport determined by procedural care within 1-h of transfer at an urban level I trauma center. METHODS: All trauma patients transported by helicopter from January 2015-December 2017 to an urban level I trauma center from referring hospitals or the scene were retrospectively analyzed. A subgroup analysis was performed evaluating patients that required a procedure or operation within 1-h of transport compared with the remainder of the patient cohort who were transported via helicopter. RESULTS: A total of 1590 patients were transported by helicopter. Thirty-nine percent of patients (n = 612) were admitted directly to the floor from the trauma bay and 16% (n = 249) of patients required only observation or were discharged home after helicopter transfer. Approximately one-third of the entire study cohort (36%, n = 572) required any procedure, with a median time to procedure of 31.5 h (interquartile range 54.4). Only 13% (n = 74) required a procedure within 1-h of helicopter transport. The average distance (in miles) if the patient had been driven by ground transport rather than helicopter was 67.0 miles (SD ± 27.9) and would take an estimated 71.5 min (±28.4) for patients who required a procedure within 1-h compared with 61.6 miles (SD ± 30.9) with an estimated 66.1 min (SD ± 30.8) for the remainder of the cohort (P value 0.899 and 0.680, respectively). CONCLUSIONS: This analysis demonstrates that helicopter transport was not necessary for the vast majority of trauma patients transported via helicopter.

Uncrewed aircraft systems versus motorcycles to deliver laboratory samples in west Africa: a comparative economic study.

BACKGROUND: Transportation of laboratory samples in low-income and middle-income countries is often constrained by poor road conditions, difficult geographical terrain, and insecurity. These constraints can lead to long turnaround times for laboratory diagnostic tests and hamper epidemic control or patient treatment efforts. Although uncrewed aircraft systems (UAS)-ie, drones-can mitigate some of these transportation constraints, their cost-effectiveness compared with land-based transportation systems is unclear. METHODS: We did a comparative economic study of the costs and cost-effectiveness of UAS versus motorcycles in Liberia (west Africa) for transportation of laboratory samples under simulated routine conditions and public health emergency conditions (based on the 2013-16 west African Ebola virus disease epidemic). We modelled three UAS with operational ranges of 30 km, 65 km, and 100 km (UAS30, UAS65, and UAS100) and lifespans of 1000 to 10 000 h, and compared the costs and number of samples transported with an established motorcycle transportation programme (most commonly used by the Liberian Ministry of Health and the charity Riders for Health). Data for UAS were obtained from Skyfire (a UAS consultancy), Vayu (a UAS manufacturer), and Sandia National Laboratories (a private company with UAS research experience). Motorcycle operational data were obtained from Riders for Health. In our model, we included costs for personnel, equipment, maintenance, and training, and did univariate and probabilistic sensitivity analyses for UAS lifespans, range, and accident or failures. FINDINGS: Under the routine scenario, the per sample transport costs were US$0·65 (95% CI 0·01-2·85) and $0·82 (0·56-5·05) for motorcycles and UAS65, respectively. Per-sample transport costs under the emergency scenario were $24·06 (95% CI 21·14-28·20) for motorcycles, $27·42 (95% CI 19·25-136·75) for an unadjusted UAS model with insufficient geographical coverage, and $34·09 (95% CI 26·70-127·40) for an adjusted UAS model with complementary motorcycles. Motorcycles were more cost-effective than short-range UAS (ie, UAS30). However, with increasing range and operational lifespans, UAS became increasingly more cost-effective. INTERPRETATION: Given the current level of technology, purchase prices, equipment lifespans, and operational flying ranges, UAS are not a viable option for routine transport of laboratory samples in west Africa. Field studies are required to generate evidence about UAS lifespan, failure rates, and performance under different weather conditions and payloads. FUNDING: None.

Cost-Effectiveness of Stock Epinephrine Autoinjectors on Commercial Aircraft.

BACKGROUND: In-flight food-allergic reactions are rare events, but given increasing reports, grass-root advocates have lobbied to replace aircraft emergency kit epinephrine ampules with autoinjectors. OBJECTIVE: To evaluate the cost-effectiveness of stock epinephrine on commercial aircraft. METHODS: We conducted a Markov model with microsimulation of food-allergic individuals over an 80-year time horizon to evaluate the cost-effectiveness of supplementing airline medical kits with epinephrine autoinjectors (eg, providing autoinjector twin-packs in addition to the epinephrine ampule in the medical kit), versus not doing so, using a per-plane annual value-based cost ceiling of $338 (the value-based ceiling for school stock epinephrine). We assumed that autoinjector availability reduced fatality risk by 10%. RESULTS: Equipping all commercial aircraft with autoinjectors cost $2,470,422/year ($0.08/passenger-at-risk), from a societal perspective and when distributed over all at-risk travelers. Over the model horizon, the supplemental autoinjector strategy cost $32,329.29 (standard deviation [SD], $4024.32) versus $32,326.70 (SD $4024.29), produced 26.8917 quality-adjusted life-years (QALYs) (SD, 2.9720) versus 26.8915 (SD, 2.9725), with a lower fatality rate (0.00012; SD, 0.01095 vs 0.00015; SD, 0.1225) versus the ampule-only strategy. The incremental cost-effectiveness ratio of supplemental airline epinephrine autoinjectors was $10,766/QALY in the base-case analysis. The supplemental model remained cost-effective at a willingness to pay threshold of $100,000/QALY if it produced a minimum 1.4% annual food allergy fatality risk reduction, and dominated if it lowered diversion risk or event-related medical care costs-per-event by 10%, respectively. CONCLUSIONS: Under base-case scenarios, an airline supplemental stock epinephrine model is cost-effective, with a high value-based cost-ceiling and low annual cost per passenger-at-risk of $0.08.

A low-cost, autonomous mobile platform for limnological investigations, supported by high-resolution mesoscale airborne imagery.

Two complementary measurement systems-built upon an autonomous floating craft and a tethered balloon-for lake research and monitoring are presented. The autonomous vehicle was assembled on a catamaran for stability, and is capable of handling a variety of instrumentation for in situ and near-surface measurements. The catamaran hulls, each equipped with a small electric motor, support rigid decks for arranging equipment. An electric generator provides full autonomy for about 8 h. The modular power supply and instrumentation data management systems are housed in two boxes, which enable rapid setup. Due to legal restrictions in Switzerland (where the craft is routinely used), the platform must be observed from an accompanying boat while in operation. Nevertheless, the control system permits fully autonomous operation, with motion controlled by speed settings and waypoints, as well as obstacle detection. On-board instrumentation is connected to a central hub for data storage, with real-time monitoring of measurements from the accompanying boat. Measurements from the floating platform are complemented by mesoscale imaging from an instrument package attached to a He-filled balloon. The aerial package records thermal and RGB imagery, and transmits it in real-time to a ground station. The balloon can be tethered to the autonomous catamaran or to the accompanying boat. Missions can be modified according to imagery and/or catamaran measurements. Illustrative results showing the surface thermal variations of Lake Geneva demonstrate the versatility of the combined floating platform/balloon imagery system setup for limnological investigations.

Quantification of avian hazards to military aircraft and implications for wildlife management.

Collisions between birds and military aircraft are common and can have catastrophic effects. Knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. Despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. We hypothesized that species relative hazard scores would correlate positively with aircraft type and avian body mass. Only strike records identified to species that occurred within the U.S. (n = 36,979) and involved United States Navy or United States Air Force aircraft were used to calculate relative hazard scores. The most hazardous species to military aircraft was the snow goose (Anser caerulescens), followed by the common loon (Gavia immer), and a tie between Canada goose (Branta canadensis) and black vulture (Coragyps atratus). We found an association between avian body mass and relative hazard score (r2 = 0.76) for all military airframes. In general, relative hazard scores per species were higher for military than civil airframes. An important consideration is that hazard scores can vary depending on aircraft type. We found that avian body mass affected the probability of damage differentially per airframe. In the development of an airfield wildlife management plan, and absent estimates of species strike risk, airport wildlife biologists should prioritize management of species with high relative hazard scores.

The Trade-Off between Optimizing Flight Patterns and Human Health: A Case Study of Aircraft Noise in Queens, NY, USA.

Objectives: Airports in the U.S. have gradually been transitioning to automated flight systems. These systems generate new flight paths over populated areas. While they can improve flight efficiency, the increased noise associated with these novel flight patterns potentially pose serious health threats to the overflown communities. In this case study, we estimated the monetary benefits relative to health losses associated with one significant change in flight patterns at LaGuardia Airport, year-round use of "TNNIS Climb", which happened in 2012 as a result of flight automation in New York City. Prior to that, the use of the TNNIS Climb was limited to the U.S. Open tennis matches. Methods: We developed a decision-analytic model using Markov health states to compare the costs and quality-adjusted life years (QALYs) gained associated with the limited use of TNNIS (old status quo) and the year-round use of TNNIS (current status quo). The TNNIS Climb increases airplane noise to above 60 decibels (dB) over some of the most densely populated areas of the city. We used this increased exposure to noise as the basis for estimating ground-level health using data from sound monitors. The total costs (including both direct and indirect costs), QALYs, and the incremental cost-effectiveness ratio (ICER) were estimated for the limited versus the year-round use of the TNNIS Climb. Results: The incremental lifetime costs and QALYs per person exposed to noise associated with the limited versus the year-round use of TNNIS was $11,288, and 1.13, respectively. Therefore, the limited use of TNNIS had an ICER of $10,006/QALY gained relative to the year-round of TNNIS. Our analyses were robust to changes in assumptions and data inputs. Conclusions: Despite increases in efficiency, flight automation systems without a careful assessment of noise might generate flight paths over densely populated areas and cause serious health conditions for the overflown communities.

Tripartite equilibrium strategy for a carbon tax setting problem in air passenger transport.

Carbon emissions in air passenger transport have become increasing serious with the rapidly development of aviation industry. Combined with a tripartite equilibrium strategy, this paper proposes a multi-level multi-objective model for an air passenger transport carbon tax setting problem (CTSP) among an international organization, an airline and passengers with the fuzzy uncertainty. The proposed model is simplified to an equivalent crisp model by a weighted sum procedure and a Karush-Kuhn-Tucker (KKT) transformation method. To solve the equivalent crisp model, a fuzzy logic controlled genetic algorithm with entropy-Bolitzmann selection (FLC-GA with EBS) is designed as an integrated solution method. Then, a numerical example is provided to demonstrate the practicality and efficiency of the optimization method. Results show that the cap tax mechanism is an important part of air passenger trans'port carbon emission mitigation and thus, it should be effectively applied to air passenger transport. These results also indicate that the proposed method can provide efficient ways of mitigating carbon emissions for air passenger transport, and therefore assist decision makers in formulating relevant strategies under multiple scenarios.

Helistroke: neurointerventionalist helicopter transport for interventional stroke treatment: proof of concept and rationale.

BACKGROUND AND PURPOSE: It is increasingly recognized that time is one of the key determinants in acute stroke outcome when interventional stroke therapy is applied. With increasing device efficacy and understanding of imaging triage options, reducing pre-treatment time loss may be a critical component of improving interventional stroke outcomes for the population at large. Time sensitive procedures such as organ harvest have transported physicians to the patient site to improve time to procedure. Applying this same principle to interventional stroke management may be a valid paradigm. METHODS: Previous logistical deliberation with hospital and Medevac companies was carried out to provide the rationale and funding for helicopter transfer of a neurointerventionalist to an in-network hospital with an on-site angiographic suite. An appropriate patient with large vessel occlusion and an NIH Stroke Scale score >8 was identified. MRI was performed, then the Medevac transport system was activated and the intervention was carried out. Times were collected during the case and assessed for time efficiency. RESULTS: The proof of concept case was identified and Medevac was consulted at 12:13 after verifying that no in-house emergencies would prevent physician departure. Weather clearance was obtained and stroke intervention confirmed as a go at 12:24. Groin puncture occurred at 13:07 and the intervention was completed at 13:41. The total time from decision-to-treat to groin puncture was 43 min and groin closure was completed at 77 min from decision-to-treat. CONCLUSIONS: This proof of concept case is presented for logistical, financial and use-case analysis. As it is a first case, times can likely be improved. We assert that this model may be another option in the spoke-and-hub design of stroke systems of care.

Return on Investment Analysis of Health Experts onLine at Portsmouth: A 2-Year Review of the Navy's Newest Teleconsultation System.

BACKGROUND: Health Experts onLine at Portsmouth (HELP) is a web-based teleconsultation system launched in June 2014 to facilitate communication between specialists at Naval Medical Center Portsmouth and providers assigned to both the fleet forces and primary care clinics across the eastern United States, Europe, and the Middle East. Specialist consultations through the HELP system purport to improve access to care for patients who otherwise might be referred to the civilian network or medically evacuated (MEDEVACed) to Naval Medical Center Portsmouth for specialized care. If HELP-facilitated communications help avoid civilian referrals or MEDEVACs, the associated costs of that care should be reduced. METHODS: We evaluated cost savings associated with prevented MEDEVACs by analyzing both tangible savings (prevented costs of flights, per diems, and consults) and intangible savings (reduced lost productivity time). We compared these savings to the costs of maintaining and utilizing the HELP system: startup costs, administrative costs, and provider time costs. We used patient and provider data from the HELP database to evaluate clinical consult cases. Before this analysis, a panel of 3 physicians associated with HELP reviewed each consult to determine whether a case qualified as a prevented MEDEVAC. Data from the Military Health System (MHS) Management and Analysis Reporting Tool and the MHS Data Repository were used to estimate costs associated with provider time, patient time, and direct care medical encounters. FINDINGS: The HELP program delivered measurable, positive returns on investment (ROIs) between June 2014 and December 2015. In that time frame, 559 consult cases occurred in the HELP system. Of the 559 total consult cases, 50 consults prevented MEDEVACs. Incorporating only tangible savings, HELP produced an 80% ROI on the basis of prevented medical evacuations; the addition of intangible savings such as reduced lost productivity increased the ROI to 250%. The dollar values of these savings were $693,461 and $1,337,628, respectively. IMPACT: The HELP program produces considerable savings (both tangible and intangible) to the Military Healthcare System for small costs. It does this both by increasing access to care at previously inaccessibly remote medical treatment facilities and by consequently decreasing the forward provider's reliance on medical evacuation in questionable cases. This positive ROI was potentially underestimated as this analysis did not account for recapture of care that would otherwise have been sent to the civilian market. On the basis of this analysis, a low bandwidth, asynchronous, and internet accessible teleconsultation system is both a feasible and effective means of projecting quality care forward into the deployed setting. Future implementation of similar initiatives throughout the MHS can be expected, and will likely draw from the lessons learned during the successful implementation and execution of the HELP system.

Congestion Pricing for Aircraft Pushback Slot Allocation.

In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the "external cost of surface congestion" is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm.

Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 µg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 µg/m(3), overall median 4.9 µg/m(3), range 0.4-44 µg/m(3)), acetaldehyde (overall average 6.5 µg/m(3), overall median 4.6, range 0.3-90 µg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft.

Risk Analysis for Unintentional Slide Deployment During Airline Operations.

We present a risk analysis undertaken to mitigate problems in relation to the unintended deployment of slides under normal operations within a commercial airline. This type of incident entails relevant costs for the airline industry. After assessing the likelihood and severity of its consequences, we conclude that such risks need to be managed. We then evaluate the effectiveness of various countermeasures, describing and justifying the chosen ones. We also discuss several issues faced when implementing and communicating the proposed measures, thus fully illustrating the risk analysis process.

Overuse of helicopter transport in the minimally injured: A health care system problem that should be corrected.

BACKGROUND: Mortality benefit has been demonstrated for trauma patients transported via helicopter but at great cost. This study identified patients who did not benefit from helicopter transport to our facility and demonstrates potential cost savings when transported instead by ground. METHODS: We performed a 6-year (2007-2013) retrospective analysis of all trauma patients presenting to our center. Patients with a known mode of transfer were included in the study. Patients with missing data and those who were dead on arrival were excluded from the study. Patients were then dichotomized into helicopter transfer and ground transfer groups. A subanalysis was performed between minimally injured patients (ISS < 5) in both the groups after propensity score matching for demographics, injury severity parameters, and admission vital parameters. Groups were then compared for hospital and emergency department length of stay, early discharge, and mortality. RESULTS: Of 5,202 transferred patients, 18.9% (981) were transferred via helicopter and 76.7% (3,992) were transferred via ground transport. Helicopter-transferred patients had longer hospital (p = 0.001) and intensive care unit (p = 0.001) stays. There was no difference in mortality between the groups (p = 0.6).On subanalysis of minimally injured patients there was no difference in hospital length of stay (p = 0.1) and early discharge (p = 0.6) between the helicopter transfer and ground transfer group. Average helicopter transfer cost at our center was $18,000, totaling $4,860,000 for 270 minimally injured helicopter-transferred patients. CONCLUSION: Nearly one third of patients transported by helicopter were minimally injured. Policies to identify patients who do not benefit from helicopter transport should be developed. Significant reduction in transport cost can be made by judicious selection of patients. Education to physicians calling for transport and identification of alternate means of transportation would be both safe and financially beneficial to our system. LEVEL OF EVIDENCE: Epidemiologic study, level III. Therapeutic study, level IV.

Remotely piloted aircraft systems as a rhinoceros anti-poaching tool in Africa.

Over the last years there has been a massive increase in rhinoceros poaching incidents, with more than two individuals killed per day in South Africa in the first months of 2013. Immediate actions are needed to preserve current populations and the agents involved in their protection are demanding new technologies to increase their efficiency in the field. We assessed the use of remotely piloted aircraft systems (RPAS) to monitor for poaching activities. We performed 20 flights with 3 types of cameras: visual photo, HD video and thermal video, to test the ability of the systems to detect (a) rhinoceros, (b) people acting as poachers and (c) to do fence surveillance. The study area consisted of several large game farms in KwaZulu-Natal province, South Africa. The targets were better detected at the lowest altitudes, but to operate the plane safely and in a discreet way, altitudes between 100 and 180 m were the most convenient. Open areas facilitated target detection, while forest habitats complicated it. Detectability using visual cameras was higher at morning and midday, but the thermal camera provided the best images in the morning and at night. Considering not only the technical capabilities of the systems but also the poachers modus operandi and the current control methods, we propose RPAS usage as a tool for surveillance of sensitive areas, for supporting field anti-poaching operations, as a deterrent tool for poachers and as a complementary method for rhinoceros ecology research. Here, we demonstrate that low cost RPAS can be useful for rhinoceros stakeholders for field control procedures. There are, however, important practical limitations that should be considered for their successful and realistic integration in the anti-poaching battle.