key: cord-272933-b2phq37e authors: Alonso Tabares, Diego title: An airport operations proposal for a pandemic-free air travel date: 2020-10-08 journal: J Air Transp Manag DOI: 10.1016/j.jairtraman.2020.101943 sha: doc_id: 272933 cord_uid: b2phq37e The aviation industry needs to work on the resilience of air travel against health threats and regain passenger trust. This paper proposes a pandemic-free travel concept based on creating an infectious diseases free zone in the airport terminal building through screening of passengers, crews and airport workers. This research shows that infectious disease detection methods applicable at the airport could be available in a short timeframe, at affordable cost and in scale. The potential location of passenger health screening, facilitation requirements, health responsibilities delegation and appropriate usage of industry standards for regulations are key elements to a potential implementation that would be phased and long term. The impact of the COVID-19 disease on air travel has been dramatic, making it the worst aviation crisis ever (ICAO, 2020a) . The perspectives for recovery of air travel are bleak, with an estimated return to the 2019 traffic level to take 4 to 5 years (IATA, 2020a) . The International Civil Aviation Organization (ICAO) was created in 1944, in article 14 of its convention stated: "Each contracting State agrees to take effective measures to prevent the spread by means of air navigation of cholera, typhus (epidemic), smallpox, yellow fever, plague, and such other communicable diseases …" (ICAO, 1944) . This intent was reinforced in the 2010 ICAO general assembly, urging all States to join and participate in the Cooperative Arrangement for the Prevention of Spread of Communicable Disease through Air Travel (CAPSCA) (ICAO, 2010) . Just looking at the 21st century, prior to COVID-19, the occurrences of pandemics has been frequent: South Asian Respiratory Syndrome (SARS, 2002 (SARS, -2003 , swine flu (2009) (2010) , Middle East respiratory syndrome (2012), Ebola (2014 Ebola ( -2016 and Zika virus (2015 Zika virus ( -2016 . All these health crises had a much lesser impact than the COVID-19. Further to SARS, the World Health Organisation (WHO) revised the International Health Regulations (IHR) in 2005 providing a legal framework "to prevent, protect against, control and provide a public health response to the international spread of disease …" (WHO, 2005) . There has been some research on the methods and screening strategies during a pandemic (Gaber et al, 2009; Gold, 2019) . However, these outbreaks represented some early warnings that have not been fully acknowledged worldwide. For example, still in 2015 in the U.S.A., a comprehensive national plan for air travel and communicable disease was not yet ready (U.S. Governmental Accountability Office, 2015). One of the reasons for air travel to be the safest transport means is to learn from past events. As an industry, resilience of air travel needs continuous improvement. First, preparing to restart and recover aviation to normal traffic levels; then, being ready for the next health crisis and secure passenger confidence in air travel (IATA, 2020b) . The first objective for aviation remains to reach the highest possible safety level. The WHO defines infectious diseases as diseases "caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another." (WHO, 2020a) . The scope in this paper for infectious disease is related to any high contagious and life-threatening disease. Pandemic-free air travel will be reached when the following cases for an infectious disease are both reduced to a minimum reasonably practicable risk: -Contamination between individuals (passenger, crews and workers at the airport) during the travel journey. -Transport of infected persons to different parts of the world. The objective of this paper is to demonstrate what could be done at the airport to continue air travel while reducing the risk of communicable diseases to a minimum. This would result in having the whole air travel free of pandemics and lead to a more resilient air travel industry. This paper is organised as follows: the topic is introduced in Chapter 1 (this section), then the current status is described in Chapter 2; the proposed solutions are discussed in Chapter 3 with the analysis of the steps to take in Chapter 4. Finally, the conclusions are presented in Chapter 5. World passenger traffic dropped by − 94.3% in April 2020 compared to the previous year. "Aviation has been shut down" (ICAO, 2020a (ICAO, -2020b impacting travelers and economies as never seen before. The global lockdown and travel restrictions have limited flying to critical air cargo transport for several months. As of July 2020, there are still many countries that have full travel bans or impose quarantine on arrival passengers and only less than ten countries have no travel restrictions (IATA, 2020c) . COVID-19 is caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus-2), a newly discovered virus from the coronavirus family. The clinical picture of COVID-19 is highly variable. Most commonly observed symptoms include fever, cough and shortness of breath. In the majority of cases the symptoms seem to be mild or are not even recognized. (CDC, 2020a) . Based on existing literature the incubation period (the time from exposure to development of symptoms) ranges from 2 to 14 days, with most of the cases being 4-6 days. The infectious period (the time when the disease can be spread) ranges 8-10 days, but starts 1-3 days before symptoms appear. This greatly contributes to the uncontrolled spread, since virus carriers are often still active and not aware of carrying the virus (Lau E.H.Y et al., 2020; Lessler J. et al., 2020) . It is assumed that the virus spread is mainly through person-to-person contact via respiratory droplets and aerosols, when they are in close proximity to others in poorly ventilated areas for prolonged periods of time. The probability of smear infection, via surfaces contact, is considered to be negligible in most of the cases (Goldman, 2020) . The companies working at the airport terminal building premises (airports, airlines, ground handlers, national agencies, subcontracted personnel, retailers …) are implementing the following measures to continue or resume operations (ACI-Europe, 2020; Changi airport, 2020; U.S. Department of Transportation, 2020), to prevent the spread of COVID-19: -Cleaning and sanitizing: enhancing sanitation of floors, carpets, high-contact areas … also, providing hand sanitizers and wipes for facility users. -Information: communicating in advance the right information via their website andapplication, with posters, videos and audio announcements on site. -Process adaptation: promoting self-servicing, electronic ticketing and touchless kiosks for all airport processes (check-in, bag-drop, immigration, boarding gate ….). Limiting the number of people at the terminal to only passengers, with no companions. Changing the security check to avoid pat-down and secondary search; adapting customs and immigration controls to avoid any document exchange. -Protecting employees working at the airport: use of polycarbonate partition wall panels to separate staff from passengers. -Social distancing (varying from 1 to 2 m): using floor markers to materialize queues and waiting points, queue management, seat arrangement, controlling flows, avoiding crowding and using available equipment accordingly (e.g. by assigning to a baggage carousel only one flight, and using only one out of two available). -Aircraft boarding and deplaning procedures: smaller groups with more sequencing, more shuttle buses if aircraft in remote stand, limitations to hand luggage on aircraft … -Terminal heating, ventilation and air conditioning: increasing the ratio of fresh air, minimizing air recirculation and changing filters regularly. -Wearing face masks: encouraged to everybody within the airport premises. Mandatory when imposed by the airport home country in public places or means of transport (AENA, 2020). It is to be noted that many of these measures are only feasible with a very low traffic level. Specifically, social distancing related measures with pre-COVID-19 traffic levels are not possible as the airports do not have enough surface to implement them. Self-service and increased information availability at airports were a trend already present that will continue and increase (ACI, 2020b). Enhanced cleaning standards, touchless journey and less physical interaction between passengers and airport employees are most likely staying for the long term as well. In principle, the remaining measures against COVID-19 are of interim nature, waiting for availability of a safe vaccine, effective treatment, herd immunity or virus disappearance to happen. There has been the intent for COVID-19 detection with the use of passenger temperature checks and the collection of passenger health self-declaration forms both on departure and on arrivals (Paris airports, 2020). Sometimes it has also been combined with a visual inspection. However, given the available scientific evidence, the European Aviation Safety Agency (EASA) and European Centre for Disease Control (ECDC) state "that entry screening using temperature control is a high-cost, low-efficiency measure" and "ECDC does not support the widespread implementation of exit or entry screening" [based on temperature checks] (EASA, 2020; ECDC, 2020). Health self-declaration is only effective based on the good faith of passengers and acts more as a deterrent to travel for risk passengers. As such, it is prompt to fraud despite any potential sanctions and a huge challenge to trace back any contagions (ECDC, 2020). In addition, for most of the individuals their symptoms are mild or not even recognized, but they can still spread the virus. Even a person that will develop symptoms has a window of up to 3 days where can present no symptoms and still be infectious (Lau E.H.Y et al., 2020; Lessler J. et al., 2020) . As of July 2020, there have been several airports where Polymerase Chain Reaction (PCR) tests have been used to detect infected passengers or airport workers, see Table 1 (Alaska Department of Transportation and Public Facilities, 2020; Port Authority NY NJ, 2020; Frankfurt airport, 2020; Munich airport, 2020; Sheremetyevo airport, 2020; Iceland Directorate of Health, 2020; Vienna airport, 2020; Paris airport, 2020; Hong Kong airport, 2020). These PCR tests need a human body fluid sample extraction (swab from nose or throat) and generally while waiting for the result, isolation or quarantine measures are requested. The main purpose of these tests is to offer an alternative for the two weeks quarantine to arrival passengers. Most airports have limited PCR testing capacity (around 500 tests per day as quoted for JFK and 2000 for Frankfurt). PCR tests are also intended to be deployed progressively to main international German and French airports (Associated Press, 2020); in the short term, other airports around the world will be adding this capability (Brussels, Amsterdam, Istanbul, San Francisco …) The proposed pandemic-free airport concept is similar to the measures put in place for airport security. This concept consists in filtering out infected passengers, crew and workers before they enter the sterile airport zone. A multi-layered risk-management approach is used together with aviation safety management system principles to achieve this aim. Comparing this major sanitary COVID-19 crisis with the September 11th 2001 security crisis, some lessons can be learnt: -Passengers will not understand different kinds of measures and requirements at different parts of the world if not properly coordinated and communicated. A holistic and accepted worldwide approach for the whole aviation industry is absolutely needed. -The lead time for deployment of permanent measures is very long (e. g. 100% hold bag screening did not happen before 2006). Permanent measures need to be defined and agreed as quickly as possible at the highest international level. -Similar crisis seem to appear (e.g. 2006 for liquids and gels threats for security). As seen in Chapter 1, the historical average in this century is one international health crisis every four to five years. More outbreaks are to be expected. The industry needs to be better prepared and not stop all activity once the current crisis is under control. -Deployment of costly passenger facilitation measures will be limited. For example, the majority of airport security checks still require the removal of laptops and liquids from the hand luggage because of the cost of the required scanners. -Measures need to be in line with the actual risk level to avoid an unnecessary burden on the passenger. A modular and adaptable approach depending on the threat level is needed. The ICAO Public Health Corridor (PHC) (ICAO, 2020c-2020d) is a good basis to address the COVID-19 crisis globally based on risk management. The ICAO PHC defines the conditions for healthy travel between two airports. This principle may be key to allow continuation of flying when the next infectious disease threat arrives: The ICAO PHC creates a framework and responsibilities (see Fig. 1 ) for the crew, aircraft, airport facilities, passenger and cargo with guidelines on how to achieve a COVID-19 free status. It also provides the forms to report on the status for each party and a certification for achieved standards with an allocated responsibility to make the audits. All guidelines, forms and certifications should be valid and applicable worldwide. An example of the implementation of the PHC for the airport facilities is the Airports Council International (ACI) health accreditation program (ACI, 2020a). However, the ICAO PHC does not specifically address the health risk related to the employees working at the airport: airline ground staff, ground handlers, retailers, police & immigration officers, cleaning and facility maintenance. This population accounts for a significant amount of the public that transit the airport terminal. These airport workers should also be addressed. The passenger's companions at the airport but not taking a plane (i.e. meeters and greeters) are not considered either. Similarly, for the airport's supplies: inputs (e.g. duty-free goods, food …) and outputs (e.g. waste) would need to be added to complete this ICAO PHC framework. Disinfection of airport facilities (ACI-Europe, 2020), cargo and aircraft (Airbus, 2020a; Boeing, 2020) is relatively easily achievable from both technical and operational perspectives. For other items like food supplies and catering, standards exist and are already applied. In order to ensure that a part of the terminal building remains an infectious disease-free zone, a filtering process is required for any person entering. This health screening should not be considered as a medical check, but needs nevertheless to be based on international standards and on medical evidence. The main difficulty with health screening is to accurately detect and filter out infectious people (i.e. passengers, crew or airport workers infected and who can infect other persons). To be able to detect an infectious but asymptomatic individual, while ensuring symptoms that are not caused by an infectious disease can be distinguished. It should not be a requirement that only perfectly healthy persons can fly. There are several methods and techniques currently used or researched for COVID-19 detection for air travel. IATA has issued a position paper on COVID-19 testing (IATA, 2020d). Some of these methods were previously used for the detection of other infectious diseases or for explosives. The major research effort for COVID-19 may be generalized to cover also other future infectious diseases. Each infectious disease has its particular characteristics (e.g. incubation period) and associated symptoms in humans. The symptoms can be correlated to the originating disease. This 'symptoms fingerprint' can be used for comparison with the test results. Even for new or mutated viruses, the timespan between their appearance and their characterization of the symptoms can be only a matter of weeks (Zhou P et al., 2020; Zhu N et al., 2020) . A non-exhaustive list of detection techniques, there are constantly new developments, is proposed in Table 2 . This list is sorted from worse to better according to the level of intrusiveness for the person tested: The benchmark for COVID-19 detection are the PCR tests, as seen in Table 1 , based on nasal or throat swabs used to identify infected individuals. Serologic tests are used to detect the presence of antibodies, but they are not useful to diagnose an active infection (CDC, 2020b). There are developments to use saliva for the PCR tests (Covidtracker, 2020; Skillcell-Alcen, 2020). Research in ongoing using spectrography on saliva (Reuters, 2020a ) and on the breath chemical composition, using a device similar to a breathalyzer (BioWorld, 2020). For non-intrusive tests, the analysis of respiratory sounds when breathing looks for cough and shortness of breath markers (Voice Study, 2020). Air sniffers can be used by dogs (DW, 2020; UK Government, 2020), an electronic nose (Airbus, 2020b) or air samplers (; Pathsensors, 2020) . There is also a potential usage of sensors for a non-invasive skin scan to detect possible symptoms (Israel 21c, 2020). There has been great advance in the development of these techniques and associated logistics for an airport site. Testing requires not only test material but also trained personnel to perform them. The PCR testing (see Table 1 ) can be taken as an example. The time to get results was first measured in days. Mainly due to the capacity of the laboratories to treat the samples, and the time to transport the samples from the airport to the main laboratory. Then, the time is reduced to hours with the higher capacity in the laboratories and is currently just one hour in Moscow (Sheremetyevo airport, 2020) where samples are treated on site with a point-of-care device. For some of the other tests means described, test results are claimed to take one minute (BioWorld, 2020) or even instantly (Reuters, 2020a) . Several of the previously mentioned detection systems are already in operation (e.g. PCR), some are undergoing clinical trials while others are still in the research phase. With all the COVID-19 research efforts ongoing, it can be expected that some of the methods still in development may be ready for a proof of concept stage in an airport by the end of 2020. Not all of them will reach the operational phase, but there should be enough choice and competition to set up an appropriate health screening method. It is assumed that economies of scale will apply to meet foreseeable high demand. The cost per test is expected to reach an affordable price level in the order of euros and be available for production at massive scale. There are already companies (Reuters, 2020a) claiming costs of less than one euro per test. Important to note that the information provided for the methods in this section do not cover the medical validation status. Any testing, even non-intrusive tests, will need to go through validation by a health agency or research institute prior to starting actual operations in an airport. The detection systems installed at the airport will be based on hardware and software. As stated before, it should be easy to upgrade the software once a new disease appears (or an existing one mutates). The installed hardware in the airport facilities should not require changes to keep the costs of upgrades low. The use of artificial intelligence has a great potential in this field as well. Most of the non-intrusive tests listed above, could be configured to analyse a continuous flow of passengers while walking freely or queuing. Additionally, their typical time for measuring and processing the information for detection is in seconds. By contrast, intrusive tests require a specific point of control to be set-up with the associated trained personnel as they need a body fluid sample. Taking into account all previous considerations, it is assumed that several systems will be available in the near future for COVID-19 detection. And these systems may be generalized for other existing and future communicable diseases. The locations where the passengers could be health screened will depend on the type of detection system, airport layout, operational constraints, local and legal requirements and responsibilities sharing between the different airport stakeholders. Testing could be done at dedicated locations in the airport or integrated in existing processes (e.g. security check). There is also the possibility to make this screening in a continuum during several segments of the whole passenger journey. This journey can be split in different processes as depicted in Fig. 2 , where potential locations are indicated: For a passenger, the potential health screening location options at specific airport process locations are depending on the passenger flow types: -Departure flow: when entering the airport terminal building, at the security check, prior to aircraft boarding (for specific flights). -Arrival flow: just after deplaning the aircraft before mixing with other arriving passengers (typically for high risks flights), prior to border control for all incoming flights depending on arrival country policy and its quarantine rules. -Transit and transfer flow: combination of the two previous flows depending on the airport set-up. o Spectrography -Body temperature measurement (by handheld thermometers) -Respiratory and heart rate -Respiratory sounds -Air sniffers -Body temperature measurement (by thermographic cameras) -Skin scans -Off-airport: on a medical facility, able to issue a certificate that is recognized by the travel stakeholders in the countries to be visited. A dedicated flow within the terminal building, similar to trusted passengers' schemes at some airports, could be established where there may still be some lighter controls. This could be valid for departure and arrival flows. Possible locations for a distributed health screening in the airport are all zones where passengers walk freely or queue (e.g. boarding gate, immigration and customs control). Generally, the more upstream in the passenger flow this health screening is carried out the better. The earlier contagious passengers are filtered out, the sooner the other passengers can be relieved from healthrelated measures applicable to all the population like wearing face masks. It is to be noted that departure health screening is for infectious disease contamination prevention, whereas health screening at arrivals are considered as mitigation means (i.e. if the origin airport is not following the infectious disease detection health screening). Airport workers (both landside and airside, before and after security check respectively), need to be tested at regular intervals (e.g. every other day). The intervals will depend on the pandemic risk status and degree of contact workers may have with passengers and other airport public. They may be tested at the same health screenings used for passengers or in dedicated facilities. The airport worker health screening is different from its equivalent in security, where the person needs to go through a security check each time they go airside. The security status changes at every passage to the landside and this could occur several times a day. However, the health status of a worker will not change several times per day. In the case of aircraft crews, they already follow a dedicated flow in the airport. Therefore, a customized screening could be established depending on the risk status of the flights and the pandemic status. The airport operations facilitation requirements for the passenger health screening proposed could be summarized as: -Process time, including time for results: for individual tests less than a minute when starting operations, but less than thirty seconds would be required in steady mode. -User experience: non-intrusive tests are definitely preferred over swabs from the throat or blood samples. -Process automation: a very high-test capacity is needed to handle the passenger flow on airports. Manual systems will quickly become prohibitive due to the number of trained personnel required. Furthermore, automation avoids any health risks for staff and facilitates the passenger flow. -False negatives: to have somebody infected passing the test. This parameter is critical to restore passenger confidence. A very high-test sensitivity, greater than 99% is required. -False positives: to have somebody not infected declared infected by the test. This person would need to undergo a second round of tests, which would be an operational burden. Therefore, a specificity greater than 95% would be required. Each testing method has its limitations, so from an operational point of view, multiple detection layers may be needed, preferably based on different technologies and symptoms. Without entering statistical analysis and just for illustration: if each layer would be 80% effective for one of the intended parameters to filter the cases, then one layer would provide 80% protection, two layers 96% and three layers 99%. Etihad is applying such a multilayer approach in Abu Dhabi airport, where temperature check, heart and respiratory rate are combined (Etihad, 2020a) . The example below presents some rough numbers for a major terminal building at a large hub airport (70 million passenger per year): -Passengers: assumed 200,000 per day (25% departure, 25% arrival, 50% transfer). This would mean: o 50,000 originating departure passengers, that would need to be tested on the airport premises. Alternatively, check these passengers carry a document that certifies they are not infected according to some rules (e.g. PCR test 72 hours old maximum prior to departure). o 50,000 arriving passengers as final destination. Testing will depend on the risk level at the country of origin or transfer. Several cases may be considered: • Passengers tested at departure airports in low risk areas do not need to be retested. Some random checks could be carried out to audit the checks done previously. • Passengers tested at high risk areas could be retested if in doubt of the previous checks or to further reduce the risk. • Passengers not tested need to be checked. o 100,000 transfer passengers: if these would have been tested on departure and this information would be shared and known for the hub airport during transit, then no test would be needed. Otherwise, depending on the risk for each incoming flight (origin), testing policy will need to be defined compounded with the operational constraints already hard enough for transferring passengers at an airport. -Airport-based employees: around 20,000 having an airside badge, out of the 50,000 employees. -Airline crews: about 2,000 that will start or finish their shift at the airport every day. These numbers clearly illustrate the operational challenge for a health screening on the airport. Tests systems should also be scalable to the passenger flow as this flow will vary over time. A further complication lies in the sharing of tests results from one airport to another. Generally (except in the U.S.A. and some other terminals) the airport terminal and the airlines operating there are different entities and the airport will not know the passenger and its health results. The responsibility for risk management of a communicable disease at an airport is with the "competent authority". Article 22 of the IHR (WHO, 2005) , ratified by most countries, describes the attributions of the competent authority, but does not define who this competent authority is. Depending on the country, this responsibility is managed by the Ministry of Health, the Ministry of Transport or their equivalents. In some countries the local government is responsible and there are occasions when this responsibility is not clear (see Miami Herald, 2020) . In fact, besides the technical aspects, the most difficult part to implement a detection system could be to manage the health responsibility within the airport. The health screening, as described in this research, should not be considered as a medical check, but rather as a pre-screening or filtering of individuals within a group. The strict minimum needed to have it running on an airport would be to have the nihil obstat from medical authorities stating that the test and procedures in place are not harmful for the public and workers. As stated above, the airport has no responsibility or legal authority on the health screenings on its premises. The only entities that can currently perform these checks are: -The airline, on the basis of the captain's authority to refuse aircraft boarding to a passenger. For example: Frontier (The Washington Post, 2020) and Air Canada (Air Canada, 2020) are doing temperature checks to passengers prior to boarding. -The border police,immigration or the competent public health authority, on the basis of giving permission to access the country. Currently happening in most of the countries worldwide (IATA, 2020c; Reuters, 2020b) An airport today, even if it would detect a suspicious passenger, would not necessarily know what to do with the individual, other than to hand the passenger over to the local health authorities. These local health authorities have to be present physically in the airport and have enough resources to handle these events, which is currently not the case. Furthermore, the passenger may refuse the test results and oppose the decision. Then, a case similar to unruly passenger may appear where the airline would need to take the responsibility. Therefore, from a pragmatic point of view, a delegation of authority (but keeping the oversight) from the local health authority towards the airport, the airline or other government agency already present at the airport may be required. This arrangement could be similar to the security check: the staff are not from the police (or equivalent), but the police supervise the check configuration, staff training and have the oversight of the whole set-up. Likewise, a clear protocol needs to be established in order to know what to do with a passenger with a positive test result (true or false). This passenger may miss the flight with the associated operational and economic impact. The passenger may ask for compensation, even going through legal claims. This is most likely an unchartered territory today. For the airport, this could become a serious reputational issue as it will suffer all the consequences but with no or very limited responsibility or capacity to act on them. How to make an effective delegation of authority to the airport or to federal agents already at the airport is a topic of intense lobby and discussion. It can be seen in official statements from U.S.A. airlines and airports associations (Airlines for ACI-North America, 2020) pushing to have federal government agents, in this case TSA at the security checks, making temperature control with the associated material resources and training. Another important topic to be considered regarding responsibility is privacy. Specifically for European general data protection regulation, health insurance portability and accountability act or equivalent, that would put a lot of constraints on the use and storage of data. Regarding the financing of these health screening measures, article 40 of the IHR (WHO, 2005) requires that no charge shall be made by any state when the measures are for the protection of public health. When the measures are for the benefit of the traveller a charge may exist and shall not exceed the cost of the service. Depending on the infectious diseases considered, they may be treated as a public health issue or for the benefit of the traveller. There has been an effort by some airlines to cover the potential cost of any COVID-19 related disruption with an insurance (Emirates, 2020a) . At the end, the final funding source used for any cost related to health screening measures would be the passenger via the airline ticket with a "health screening charge". This charge may contribute partially or totally to the cost depending on the assessment by the State. This airline ticket fee would be similar to the passenger facilitation or security charge used today (Gillen and Morrison, 2015) . The implementation of a pandemic-free airport concept as described in this document will be based on the on the development of several streams that are interconnected: -Technical advances on infectious detection means. The various methods need to continue their development, including medical validation and trials in an airport environment. As stated in the previous chapter, several detection methods may need to be combined to reach a screening with the required performance and automation is a must to meet airport facilitation requirements. -Testing to mitigate or replace quarantines. The removal of quarantines is absolutely mandatory to go back from our current fragmented world to the connected world we used to live in. Quarantines are a deterrent to fly, being de facto an equivalent to a travel ban (IATA, 2020e). Furthermore, during this crisis, quarantines have been used sometimes erratically without sound justification (Reuters, 2020c) . With the detection technologies available in the 21st century, it is expected that health screening can satisfactory replace quarantine measures. This is the case in the United Arab Emirates, where a PCR negative test for COVID-19 is required for all departing, arriving or transiting passengers (Emirates, 2020b; Etihad, 2020b) . Except for the scale, historically this is nothing new as some countries request health certificates (e.g. for HIV/AIDS) or proof of vaccination (e.g. for yellow fever) (WHO, 2020b). -Build of appropriate industry standards and State regulations ICAO with the CAPSCA subgroup are working to set-up the basic guidelines and protocol for health screening as mitigation for quarantine. Once completed, these will deliver the basis on which States can build their legislation. The use of industry standards for process, methods and information exchanges is key for a wide adoption. These standards can be used as building bricks for States regulation. It is also a way to ease the start-up of regulations, their subsequent updates and mutual recognition between different States. The additional effort to generalize these regulations for future infectious diseases would be low if done at the same time with COVID-19 related updates. -Adequate health screening responsibility management As seen in Section 3.3.4, the implementation of health screening at the airport will require local health authorities to scale up resources at the airport or delegate to the airport, airline or other government agency already present. -Public opinion demand and support The COVID-19 shock will result in a worldwide, public demand for more stringent control of communicable diseases, specifically for air travel. This may replicate at a political level which would then lead to new health-related regulations impacting air travel. It is very likely that health aspects may need to be considered from now on by the aviation ecosystem and this may include airport health screening and permanent presence of health personnel at the airport. Success of the proposed concept would support public opinion being confident in air travel again, keep aviation as the safest and also healthiest travel means and prepare for future pandemics. -Backing of the air travel industry There are many stakeholders in the air travel industry worldwide. The alignment of the diverse interests to support the proposed concept will be another challenge. Health screening facilities at a given airport could be seen as a competitive advantage that may evolve into a pandemic-free airport network that would impact airline network and travel demand in general. Finally, it can be anticipated that the complete process will be lengthy, as the typical time to set up and implement will be measured in years. A tentative roadmap on how the steps to this implementation could happen is presented: -Within the airport: it may start from a specific zone in the terminal with a trial on a route (Emirates, 2020c) . Then, it will grow to cover the boarding gate and later a dedicated zone within the terminal building with several gates, for some intercontinental traffic routes. Afterwards, generalization for intercontinental and international traffic. When interest on this implementation reaches domestic flights, the zone could go from boarding gate up to the multi-purpose security and health check in the terminal. -Between airports: it may start like some bubbles with just a few airports. When starting to connect between them a safe corridor will be established (see Aviation Week, 2020). The international selected airports may be triggered by the nomination by the State of their designated points of entry. If successful, these corridors may cover a geographical and political zone (e.g. Schengen countries). Each geographical zone will set-up their own common ground, maybe with different levels of testing that need to be coherent with the others to connect seamlessly. And slowly, hopefully, one day the world will be connected pandemic-free. The air travel industry is currently fighting to overcome the effects of the COVID-19 crisis. It may take several years, but the industry will recover. However, surviving this crisis is not enough. The aviation industry needs to take action to be prepared for a similar future health crisis. Air travel needs to be resilient to these health threats to avoid a repetition of a complete traffic standstill. Pandemic-free air travel requires a pandemic-free airport. The infectious disease detection capability is the key to this end. There are sound prospects that technology will be able to deliver this capability at an affordable cost and in scale in a not so distant future. The available technology will be the enabler to trigger the responsibility discussion about the health screening. Certainly, that would mean that if departure passengers can be health screened at the airport or they have been screened off-airport appropriately, the exceptional measures as the passenger advance in the journey process and through the different filters can be lifted (e.g. social distancing requirements, wearing face coverings and quarantines). Pandemic-free travel based on a pandemic-free airport, has been sketched in this document as a tool to achieve air travel resilience to health threats. Its success will depend on technical advances on infectious detection means, acceptance to replace quarantines by testing, build of appropriate industry standards and State regulations, adequate health screening responsibility management, public opinion and support by all the air travel stakeholders. Adoption would be progressive from within one airport, to airport corridors and finally worldwide. Historically, air travel has always been focused on safety. From the 70's, and continuing today, security threats had to be dealt with as well. The COVID-19 crisis has shown us that from now on, health will be another key aspect to take into account. Safety, security and health will be the new triad for air travel. The aviation industry can and must be prepared to avoid quarantines and travel bans when future pandemics occur. The potential benefits of being well prepared outnumber the obstacles to be overcome. No confidential data has been used for this article. Diego Alonso Tabares: Conceptualization, Writing, Reviewing, Editing, Visualization. None. The article represents exclusively the personal opinion of the author and does not intend to represent his employer's position or any of his affiliations. 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