Using STACK to support student learning at masters level: a case study

The development of six online quizzes to support students’ study of an introductory mathematics masters module at The Open University is described and their use evaluated. The quizzes were implemented using the STACK online e-assessment system which is powered by a computer-algebra engine. Evaluation of student feedback and an initial quantitative study of the effect of engaging with the quizzes on the final examinations marks suggest that further development of e-assessment at mathematics masters level is warranted

Traffic synchronization with controlled time of arrival for cost-efficient trajectories in high-density terminal airspace

The growth in air traffic has led to a continuously growing environmental sensitivity in aviation, encouraging the research into methods for achieving a greener air transportation. In this context, continuous descent operations (CDOs) allow aircraft to follow an optimum flight path that delivers major environmental and economic benefits, giving as a result engine-idle descents from the cruise altitude to right before landing that reduce fuel consumption, pollutant emissions and noise nuisance. However, this type of operations suffers from a well-known drawback: the loss of predictability from the air traffic control (ATC) point of view in terms of overfly times at the different waypoints of the route. In consequence, ATC requires large separation buffers, thus reducing the capacity of the airport. Previous works investigating this issue showed that the ability to meet a controlled time of arrival (CTA) at a metering fix could enable CDOs while simultaneously maintaining airport throughput. In this context, more research is needed focusing on how modern arrival managers (AMANs)—and extended arrival managers (E-AMANs)—could provide support to select the appropriate CTA. ATC would be in charge to provide the CTA to the pilot, who would then use four-dimensional (4D) flight management system (FMS) trajectory management capabilities to satisfy it. A key transformation to achieve a more efficient aircraft scheduling is the use of new air traffic management (ATM) paradigms, such as the trajectory based operations (TBO) concept. This concept aims at completely removing open-loop vectoring and strategic constraints on the trajectories by efficiently implementing a 4D trajectory negotiation process to synchronize airborne and ground equipment with the aim of maximizing both flight efficiency and throughput. The main objective of this PhD thesis is to develop methods to efficiently schedule arrival aircraft in terminal airspace, together with concepts of operations compliant with the TBO concept. The simulated arrival trajectories generated for all the experiments conducted in this PhD thesis, to the maximum possible extent, are considered to be energy-neutral CDOs, seeking to reduce the overall environmental impact of aircraft operations in the ATM system. Ultimately, the objective of this PhD is to achieve a more efficient arrival management of traffic, in which higher levels of predictability and similar levels of capacity are achieved, while the safety of the operations is kept. The designed experiments consider a TBO environment, involving a high synchronization between all the involved actors of the ATM system. Higher levels of automation and information sharing are expected, together with a modernization of both current ATC ground-support tools and aircraft FMSs to comply with the new TBO paradigm.L’increment de tràfic aeri ha portat a una major sensibilitat mediambiental en l’aviació, motivant la recerca en mètodes per aconseguir un transport aeri més ecològic. En aquest context, les operacions de descens continu (CDOs) permeten a les aeronaus seguir una trajectòria que aporta grans beneficis econòmics i ambientals, donant com a resultat descensos amb els motors al ralentí des de l’altitud de creuer fins just abans d’aterrar. Aquestes trajectòries redueixen el consum de combustible, les emissions contaminants i el soroll generat per les aeronaus. No obstant això, aquest tipus d’operacions té un gran desavantatge: la pèrdua de predictibilitat des del punt de vista del controlador aeri (ATC) en termes de temps de pas als diferents punts de la ruta. Com a conseqüència, l’ATC necessita assignar una major separació entre les aeronaus, la qual cosa comporta una reducció en la capacitat de l’aeroport. Estudis previs investigant aquest problema han demostrat que la capacitat de complir amb un temps controlat d’arribada (CTA) a un punt de la ruta (utilitzat per seqüenciar les aeronaus) podria habilitar les CDOs tot mantenint la capacitat de l’aeroport. En aquest context, es necessita investigar més en com els gestors d’arribades (AMANs) i els gestors d’arribades ampliats (E-AMANs) podrien donar suport en la selecció de la CTA més adequada. L’ATC seria l’encarregat d’enviar la CTA al pilot, el qual, per tal de complir amb la CTA, faria servir la capacitat de gestió de trajectòries d’un sistema de gestió de vol (FMS) de quatre dimensions (4D). Una transformació clau per aconseguir una gestió més eficient del tràfic d’arribada és l’ús de nous paradigmes de gestió del tràfic aeri (ATM), com per exemple el concepte d’operacions basades en trajectòries (TBO). Aquest concepte té com a objectiu eliminar completament de les trajectòries la vectorització en “bucle obert” i les restriccions estratègiques. Per aconseguir-ho, es proposa implementar de manera eficient una negociació de la trajectòria 4D, amb l’objectiu de sincronitzar l’equipament de terra amb el de l’aeronau, maximitzant d’aquesta manera l’eficiència dels vols i la capacitat del sistema. El principal objectiu d’aquest doctorat és desenvolupar mètodes per gestionar aeronaus de manera eficient en espai aeri terminal, juntament amb conceptes d’operacions que compleixin amb el concepte de TBO. Les trajectòries d’arribada simulades per tots els experiments definits en aquesta tesi doctoral, en la mesura que s’ha pogut, són CDOs d’energia neutral. D’aquesta manera, la idea és reduir el màxim possible l’impacte mediambiental de les operacions aèries al sistema ATM. En definitiva, l’objectiu d’aquest doctorat és aconseguir una gestió del tràfic d’arribada més eficient, obtenint una major predictibilitat i capacitat, i assegurant que la seguretat de les operacions es manté. Els experiments dissenyats consideren una situació on el concepte de TBO és present, el que comporta una sincronització elevada entre tots els actors implicats en el sistema ATM. Així mateix, s’esperen nivells majors d’automatització i de compartició d’informació, juntament amb una modernització de les eines de suport en terra a l’ATC i dels FMSs de les aeronaus, tot amb l’objectiu de complir amb el nou paradigma de TBO.El incremento de tráfico aéreo ha llevado a una mayor sensibilidad medioambiental en la aviación, motivando la investigación de métodos para conseguir un transporte aéreo más ecológico. En este contexto, las operaciones de descenso continuo (CDOs) permiten a las aeronaves seguir una trayectoria que aporta grandes beneficios económicos y ambientales, dando como resultado descensos con los motores al ralentí desde la altitud de crucero hasta justo antes de aterrizar. Estas trayectorias reducen el consumo de combustible, las emisiones contaminantes y el ruido generado por las aeronaves. No obstante, este tipo de operaciones tiene una gran desventaja: la pérdida de predictibilidad desde el punto de vista del controlador aéreo (ATC) en términos de tiempos de paso en los diferentes puntos de la ruta. Como consecuencia, el ATC necesita asignar una mayor separación entre las aeronaves, lo cual comporta una reducción en la capacidad del aeropuerto. Estudios previos investigando este problema han demostrado que la capacidad de cumplir con un tiempo controlado de llegada (CTA) en un punto de la ruta (utilizado para secuenciar las aeronaves) podría habilitar las CDOs manteniendo al mismo tiempo la capacidad del aeropuerto. En este contexto, es necesario investigar más en cómo los gestores de llegadas (AMANs)—y los gestores de llegadas extendidos (E-AMANs)—podrían dar soporte en la selección de la CTA más adecuada. El ATC sería el encargado de enviar la CTA al piloto, el cual, para cumplir con la CTA, usaría la capacidad de gestión de trayectorias de un sistema de gestión de vuelo (FMS) de cuatro dimensiones (4D). Una transformación clave para conseguir una gestión más eficiente del tráfico de llegada es el uso de nuevos paradigmas de gestión del tráfico aéreo (ATM), como por ejemplo el concepto de operaciones basadas en trayectorias (TBO). Este concepto tiene como objetivo eliminar completamente de las trayectorias la vectorización en “bucle abierto” y las restricciones estratégicas. Para conseguirlo, se propone implementar de manera eficiente una negociación de la trayectoria 4D, con el objetivo de sincronizar el equipamiento de tierra con el de la aeronave, maximizando de esta manera la eficiencia de los vuelos y la capacidad del sistema. El principal objetivo de este doctorado es desarrollar métodos para gestionar aeronaves de manera eficiente en espacio aéreo terminal, junto con conceptos de operaciones que cumplan con el concepto de TBO. Las trayectorias de llegada simuladas para todos los experimentos definidos en esta tesis doctoral, en la medida de lo posible, son CDOs de energía neutra. De esta manera, la idea es reducir lo máximo posible el impacto medioambiental de las operaciones aéreas en el sistema ATM. En definitiva, el objetivo de este doctorado es conseguir una gestión del tráfico de llegada más eficiente, obteniendo una mayor predictibilidad y capacidad, y asegurando que la seguridad de las operaciones se mantiene. Los experimentos diseñados consideran una situación xxi donde el concepto de TBO está presente, lo que comporta una sincronización elevada entre todos los actores implicados en el sistema ATM. Asimismo, se esperan mayores niveles de automatización y de compartición de información, junto con una modernización de las herramientas de soporte en tierra al ATC y de los FMSs de las aeronaves, todo con el objetivo de cumplir con el nuevo paradigma de TBO. Primero de todo, se define un marco para la optimización de trayectorias utilizado para generar las trayectorias simuladas para los experimentos definidos en esta tesis doctoral. A continuación, se evalúan los beneficios de volar CDOs de energía neutra comparándolas con trayectorias reales obtenidas de datos de vuelo históricos. Se comparan dos fuentes de datos, concluyendo cuál es la más adecuada para estudios de eficiencia en espacio aéreo terminal. Las CDOs de energía neutra son el tipo preferido de trayectorias desde un punto de vista medioambiental pero, dependiendo de la cantidad de tráfico, podría ser imposible para el ATC asignar una CTA que pueda ser cumplida por las aeronaves mientras vuelan la ruta de llegada publicada. En esta tesis doctoral, se comparan dos estrategias con el objetivo de cumplir con la CTA asignada: volar CDOs de energía neutra por rutas más largas/cortas o volar descensos con el motor accionado por la ruta publicada. Para ambas estrategias, se analiza la sensibilidad del consumo de combustible a diferentes parámetros, como la altitud inicial de crucero o la velocidad del viento. Finalmente, en esta tesis doctoral se analizan dos estrategias para gestionar de manera eficiente el tráfico de llegada en espacio aéreo terminal. Primero, se utiliza una estrategia provisional a medio camino entre la negociación completa de trayectorias 4D y la vectorización en “bucle abierto”: se propone una metodología para gestionar de manera eficaz tráfico de llegada donde las aeronaves vuelan CDOs de energía neutra en un procedimiento de navegación de área (RNAV) conocido como trombón. A continuación, se propone una nueva metodología para generar rutas de llegada dinámicas que se adaptan automáticamente a la demanda actual de tráfico. De igual manera, se aplican CDOs de energía neutra a todo el tráfico de llegada. Hay diferentes factores a considerar que podrían limitar los beneficios de las soluciones propuestas. La cantidad y distribución del tráfico de llegada tiene un gran efecto sobre los resultados obtenidos, limitando en algunos casos una gestión eficiente de las aeronaves de llegada. Además, algunas de las soluciones propuestas comportan elevadas cargas computacionales que podrían limitar su aplicación operacional, motivando mayor investigación en el futuro con el fin de optimizar los modelos y metodologías utilizados. Finalmente, permitir a algunos aviones volar descensos con el motor accionado podría facilitar la gestión de las aeronaves de llegada en los experimentos que se centran en el procedimiento de trombón y en la generación de rutas de llegada dinámicas.Postprint (published version

Evaluation of a Dynamic Weather-Avoidance Rerouting Tool in Adjacent-Center Arrival Metering

Dynamic Reroutes for Arrivals in Weather (DRAW) is a NASA-developed decision-support tool for Traffic Management Coordinators (TMCs) at the Federal Aviation Administration's Air Route Traffic Control Centers ("Centers"). DRAW proposes weather-avoidance reroutes for en route arrival flights subject to metering restrictions when transitioning into a busy terminal airspace. The prior DRAW study demonstrated that TMCs' use of DRAW promotes earlier reroutes of arrivals, and reduces the number of routes conflicting with weather in the Center. The present paper focuses on how DRAW benefits metering delivery accuracy when schedule freeze horizon distance was altered. A human-in-the-loop simulation was conducted at NASA Ames Research Center in October-November 2018, where retired TMCs and controllers performed simulated metering operations for southeast arrivals through the Atlanta and Jacksonville Centers to the Hartsfield-Jackson Atlanta International Airport during convective weather periods. Results demonstrated that DRAW use reduced the frequency of manual adjustments of Scheduled Times of Arrival and lowered TMC workload. DRAW use also made the metering accuracy, the number of reroute amendments after the freeze horizon, and the en route sector controller workload more robust to the effect of different freeze horizon distance

Trajectory Clustering for Air Traffic Categorisation

Availability of different types of data and advances in data-driven techniques open the path to more detailed analyses of various phenomena. Here, we examine the insights that can be gained through the analysis of historical flight trajectories, using data mining techniques. The goal is to learn about usual (or nominal) choices airlines make in terms of routing, and their relation with aircraft types and operational flight costs. The clustering is applied to intra-European trajectories during one entire summer season, and a statistical test of independence is used to evaluate the relations between the variables of interest. Even though about half of all flights are less than 1000 km long, and mostly operated by one airline, along one trajectory, the analysis shows that, for longer flights, there exists a clear relation between the trajectory clusters and the operating airlines (in about 49% of city pairs) and/or the aircraft types (30%), and/or the flight costs (45%)

Engage D2.2 Final Communication and Dissemination Report

This deliverable reports on the communication and dissemination activities carried out by the Engage consortium over the duration of the network. Planned activities have been adapted due to the Covid-19 pandemic, however a full programme of workshops and summer schools has been organised. Support has been given to the annual SESAR Innovation Days conference and there has been an Engage presence at many other events. The Engage website launched in the first month of the network. This was later joined by the Engage ‘knowledge hub’, known as the EngageWiki, which hosts ATM research and knowledge. The wiki provides a platform and consolidated repository with novel user functionality, as well as an additional channel for the dissemination of SESAR results. Engage has also supported and publicised numerous research outputs produced by PhD candidates and catalyst fund projects

Choline consumption in Norway : Dietary sources, association with one-carbon and lipid metabolism and cardiovascular disease risk

Background: Choline is an essential nutrient involved in a wide variety of physiological functions. Through its metabolite betaine, it is closely connected to the one-carbon metabolism, and phosphatidylcholine (PC) is essential for the formation and secretion of very-low-density-lipoprotein in the liver, connecting choline to lipid metabolism. Choline is found in foods and in the body in different forms. Food products of animal origin contain higher amounts of total choline, and mainly fat-soluble forms, per unit weight compared to plant-derived products. An adequate intake (AI) has been set in the US and Europe, however, not yet in the Nordic countries. Both the one-carbon and lipid metabolism are closely related to the risk of chronic diseases. However, few studies have investigated the association between dietary choline intake and cardiovascular disease, and findings are contradictory. In Paper I and II the association between dietary choline intake and the risk of acute myocardial infarction (AMI) in patients with pre-existing coronary heart disease was addressed. Further, dietary intake of total choline and individual choline forms and their dietary contributors have not been investigated, which was the objective of Paper III and IV. Additionally, in Paper IV, the association between choline intake and plasma concentrations of one-carbon and lipid metabolites was explored in healthy community-dwelling adults. Methods: Western Norway B-vitamin Intervention Trial (WENBIT): Patients with stable angina pectoris from WENBIT (n=1981 and 1929, for Paper I and Paper II respectively) were included. Dietary data was derived from a food frequency questionnaire (FFQ) and choline content of food items was quantified using the U.S. Department of Agriculture (USDA) Database for Choline Content of Common Foods, release 2. Cox regression models were used to estimate the association between total choline intake or intake of individual choline forms and risk of AMI. Effect modification was investigated for trimethylamine N-oxide (TMAO) and trimethyllysine (TML) and mediation analysis was applied considering TMAO as a mediator. Hordaland Health Study 1997-1999 (HUSK): HUSK included community-dwelling adults, and 5746 of these were included in the current analysis. Dietary data were derived from the same FFQ used in the WENBIT cohort and choline intake was estimated using the USDA choline database. To explore the relationship between one-carbon and lipid metabolites and total dietary choline intake, choline intake was modeled as a polynomial spline. Results: The geometric mean (95% prediction interval) total energy-adjusted choline intake was 287 (182, 437) mg/d and 260 (170, 389) mg/d in the WENBIT and HUSK populations, respectively. PC was the main consumed form in both study populations and eggs contributed most to total choline intake (12.6% and 15.3% in WENBIT and HUSK respectively). Other main dietary contributors were milk, vegetables, potatoes, and lean fish. Most of the individual choline forms were primarily obtained from animal-based food sources, apart from free choline. In patients with SAP, increased intakes of energy-adjusted total choline (Hazard ratio (HR) [95% confidence interval] 1.10 [1.02, 1.19]), PC (1.23 [1.07, 1.41]), and sphingomyelin (1.15 [1.03, 1.30]) were associated with higher AMI risk. We did not observe any effect modification by plasma TMAO and TML, nor any mediation by TMAO. In community-dwelling adults, dietary choline consumption showed clear associations with plasma concentration of one-carbon metabolites and to a lesser extent with serum lipid metabolites. Conclusion: Choline was mainly consumed in the form of PC and mostly obtained from animal food sources. The self-reported choline intake was below the established AI for most of the participants. Further, total dietary choline, PC, and sphingomyelin were positively associated with AMI risk. Also, dietary choline was associated with the plasma concentration of metabolites of the one-carbon and lipid metabolism.Doktorgradsavhandlin

The HAAWAII Framework for Automatic Speech Understanding of Air Traffic Communication

During the last decade many successful applications combining Automatic Speech Recognition and Understanding (ASRU) for Air Traffic Management applications have been proposed and demonstrated. The HAAWAII project developed a generic architecture and framework, which was validated for, e.g., callsign highlighting, pre-filling radar labels and readback error detection. It supports recognizing and understanding pilot and air traffic controller (ATCo) transmissions. Contextual information extracted from available surveillance data, from flight plan data and from previous transmissions can be exploited to significantly improve ASRU performance. Different design decisions have been taken, depending on concrete scenarios. This paper evaluates the effect of the design decisions integrated in the HAAWAII framework on overall performance for speech understanding based on eight hypotheses, of which seven are validated. Using all framework elements enables command recognition rates for ATCos of 90% for real-time applications and 93% for offline applications, respectively. The most significant impact is achieved, when callsign information from surveillance data is available: the command recognition rate improves by more than 20% absolute. Knowing apriori, whether ATCo or pilot is speaking, can provide additional improvement in command recognition rate up to 16% absolute. The reported results are based on commands from apron, approach, and enroute recorded both in laboratory and in ops room environment

Modified immunoscore improves the prediction of progression-free survival in patients with non-muscle-invasive bladder cancer: A digital pathology study

Tumour-infiltrating lymphocytes (TIL), known to be of prognostic value in various solid tumours, have been in the focus of research in the last years. TIL are often quantified via IMMUNOSCORE ® (IS), a scoring system based on TIL cell densities. Recent studies were able to replicate these findings for muscle-invasive bladder cancer (MIBC), however data regarding non-muscle-invasive bladder cancer (NMIBC) are scarce. This study aimed to evaluate the value of a modified Immunoscore (mIS) as a predictive marker for NMIBC prognosis using tissue-micro-arrays (TMAs). We analysed two TMAs containing 316 samples from 158 patients with NMIBC, stained for CD3, CD8, CD45RO and FOXP3. Stained TIL were captured by digital pathology, cumulated, averaged, and reported as density (stained cells per mm²). The mIS was then constructed based on density of all four immune-cell types. Clinical, pathological and follow-up data were collected retrospectively. Univariable and multivariable cox regression analysis was performed to assess the potential value of mIS as a predictor for progression free survival (PFS) and recurrence-free-survival (RFS). Patients within "European Organisation for Research and Treatment of Cancer" (EORTC) risk groups were further substratified in high mIS and low mIS subgroups. Finally log-rank test was used to compare the different survival curves. The median age in our cohort was 68 years (Interquartile Range (IQR): 60 - 76), and 117 (74%) patients were male. A total of 26 patients (16.5%) were classified as EORTC low risk, 45 (28.5%) as intermediate risk and 87 (55.1%) as high risk. Patients in the EORTC high risk group with low mIS showed a shorter PFS in comparison to high mIS (HR 2.9, CI 0.79 - 11.0, p=0.082). In contrast, no predictive potential regarding PFS was observed in intermediate or low risk groups. Furthermore, mIS was not able to predict RFS in any EORTC risk group. mIS could be utilized to predict prognosis more accurately in high-risk patients with NMIBC by identifying those with higher or lower risk of progression. Therefore, mIS could be used to allocate these highrisk patients to more streamlined follow-up or more aggressive treatment strategies. Keywords: biomarker; bladder cancer; digital pathology; immunoscore; prognosis; progressio

Quantitative analysis and spatial and temporal distribution of volatile organic compounds in atmospheric air by utilizing drone with miniaturized samplers

Our second generation air sampling drone system, allowing the simultaneous use of four solid phase microextraction (SPME) Arrow and four in-tube extraction (ITEX) units, was employed for collection of atmospheric air samples at different spatial and temporal dimensions. SPME Arrow coated with two types of materials and ITEX with 10% polyacrylonitrile as sorbent were used to give a more comprehensive chemical characterization of the collected air samples. Before field sampling, miniaturized samplers went through quality control and assurance in terms of reproducibility (RSD = 10 min), breakthrough volume (1.8 L) and storage time (up to 48 h). 128 air samples were collected under optimal sampling conditions from July to September 2019 at the SMEAR II station and Qvidja farm, Finland. 347 VOCs were identified in the air samples either on-site or in the laboratory by thermal desorption gas chromatography - mass spectrometry, and they were quantified/semiquantified using Partial Least Squares Regression models. Individual models were developed for the different coatings and packing materials using gas phase standards obtained by an automatic permeation system. Average gas phase VOC concentrations ranged from 0.1 (toluene, the SMEAR II station) to 680 ng L-1 (acetone, Qvidja farm). Average VOC concentrations in aerosols ranged from 0.1 (1,4-cyclohexadiene, the SMEAR II station) to 2287 ng L-1 (megastigma-4,6,8-triene, Qvidja farm). Clear differences in results were seen for samples collected at the SMEAR II station and Qvidja farm, between VOC compositions in gas phase and aerosols, and between the sampling site and height.Peer reviewe

Organizational challenge or inevitability

Em 2018, o setor do transporte aéreo continuava em franca expansão. Com efeito, o número de passageiros interessados em voar permanecia superior ao número de lugares disponibilizados pelas diversas companhias aéreas a nível mundial. E os dois principais fabricantes de aviões, a Airbus e a Boeing, acumulavam ordens de encomenda que lhes garantiam uma produção contínua superior a cinco (5) anos. Porém, a satisfação dos níveis de procura por viagens aéreas está, também, diretamente ligada à disponibilidade e à capacidade das infraestruturas aeroportuárias. E, em 2018, mais de 200 aeroportos em todo o mundo já tinham esgotado a sua capacidade, sendo que, destes, 100 estão instalados no continente europeu. Portugal não foi exceção. Em apenas sete (7) anos, entre 2013 e 2019, viu o número de passageiros transportados crescer de 32,6 milhões para 60,1 milhões. Simultaneamente, o número de movimentos de aviões aumentou para mais de 418 mil movimentos anuais (o que representa um aumento superior a 65%). Lisboa, enquanto maior e principal aeroporto nacional, foi aquele que registou, em 2018, o maior aumento no número de passageiros transportados e de movimentos de aviões, totalizando mais de 29 milhões de passageiros processados e mais de 210 mil movimentos de aviões. Não obstante, quanto maior é a pressão exercida sobre a estrutura aeroportuária, maior será a probabilidade de colapso ou de uma forte diminuição dos níveis de qualidade e de pontualidade dessa mesma estrutura. Nessa medida, com uma percentagem média de partidas atrasadas de 68,6% e a maior média de partidas atrasadas (22,8 minutos), o Aeroporto de Lisboa foi classificado, em 2018, como o menos pontual de entre os 20 aeroportos europeus menos pontuais.Flight punctuality is an essential issue among passengers, airports operators, and airlines. But, like in any other means of transportation, there will always be external factors of disruption. Adverse weather, airport congestion, lack of capacity, or industrial actions are just a few examples that will, inevitably, cause delays for airlines. However, in general, airline punctuality is most influenced by the performance of airlines and airports. After being appointed in the early days of 2019, by the Official Aviation Guide (OAG), as one of the top ten least punctual airline companies in the world, TAP Air Portugal (TAP) was forced to react. While operating one of the largest and most radical upgrades of its fleet, with the phase-in and phase-out of nearly 30 aircraft in less than two (2) years, TAP implemented a series of mitigating measures to try to improve its punctuality. In this study we will analyse, not only, the measures adopted by the company, but also, try to understand the real impact that external factors (airport capacity, ATC restrictions, and handling) had on the (lack of) punctuality of the Portuguese airline in 2018 and 2019.In 2018, the average delay per departure in Lisbon International Airport (LIS) reach a record value of 22,8 minutes per flight. On the following year, LIS ranked first (#1) in the table of the twenty least punctual European airports for the second time in three (3) consecutive years (2017 and 2019). This lack of airport capacity along with the numerous ATC restrictions formed a perfect storm that TAP decided to ignore. Or, at least, it failed to anticipate. Otherwise, it would not have been possible for the company to be considered, in March 2019, as the most punctual airline among the most active European airlines in LIS