Haul Flights Research Articles

Fault Detection on Short-Haul or Highly Dynamic Flights Using Transient Flight Segments

Abstract A machine learning-based approach is presented, which allows to detect persistent engine faults after a single flight. It utilizes transient in-flight measurements and a transient engine model. The time series of the residuals between the measured data and the data resulting from performance synthesis is evaluated using moving windows containing at least one transient segment. A continuous wavelet transformation and a pretrained convolutional neural network are utilized on the residuals for feature extraction. The fault detection is carried out via a one-class support vector machine, trained exclusively on nominal engine operation data. Therefore, the approach requires no a-priory knowledge of the effects of engine faults on the in-flight measurements. Under the assumption of persistent faults, all windows of a single flight, which contain at least one transient segment, are considered in order to improve the reliability of the fault detection. This approach is validated using measured data of a small helicopter engine that replicates the dynamic flight of the corresponding model helicopter on a ground test bed. Consequently, step changes as well as complex variations of the shaft power output are considered. Four standard gas path sensors are considered. The one-class support vector machine is used successfully to detect two types of total pressure sensor anomalies. Assuming a typical number of transient segments for an average short haul flight, it turns out that persistent faults can be detected within one flight with a probability of above 90%.

Combining Fleetwide AviTeam Aviation Emission Modeling with LCA Perspectives for an Alternative Fuel Impact Assessment.

Reducing aviation emissions is important as they contribute to air pollution and climate change. Several alternative aviation fuels that may reduce life cycle emissions have been proposed. Comparative life cycle assessments (LCAs) of fuels are useful for inspecting individual fuels, but systemwide analysis remains difficult. Thus, systematic properties like fleet composition, performance, or emissions and changes to them under alternative fuels can only be partially addressed in LCAs. By integrating the geospatial fuel and emission model, AviTeam, with LCA, we can assess the mitigation potential of a fleetwide use of alternative aviation fuels on 210 000 shorter haul flights. In an optimistic case, liquid hydrogen (LH2) and power-to-liquid fuels, when produced with renewable electricity, may reduce emissions by about 950 GgCO2eq when assessed with the GWP100 metric and including non-CO2 impacts for all flights considered. Mitigation potentials range from 44% on shorter flights to 56% on longer flights. Alternative aviation fuels' mitigation potential is limited because of short-lived climate forcings and additional fuel demand to accommodate LH2 fuel. Our results highlight the importance of integrating system models into LCAs and are of value to researchers and decision-makers engaged in climate change mitigation in the aviation and transport sectors.

Passenger Preferences for Ultra Long Haul Flights vs. Connecting Flights: A Comparative Study between Asia and Europe

Passenger Preferences for Ultra Long Haul Flights vs. Connecting Flights: A Comparative Study between Asia and Europe

How much can electric aircraft contribute to reaching the Flightpath 2050 CO2 emissions goal? A system dynamics approach for european short haul flights

In 2012, the Advisory Council for Aeronautics Research in Europe (ACARE) introduced Flightpath 2050 defining the emission reduction targets for the aviation industry in the EU. The purpose of this study is to assess the impact of narrow body electric aircraft for short haul flights on reaching the Flightpath 2050 CO2 emissions goal using different policy scenarios within the EU. We develop a system dynamics model of the air transport system (ATS), consisting of the interaction between three major segments, namely air travel demand, airline industry and aircraft manufacturers. The model is run for the time period from 1991 to 2050, where electric aircraft are introduced in the year 2035. We simulate the behavior of the ATS under different policy scenarios, e.g., introduction of jet fuel tax, electricity subsidy, seat tax or fleet restriction policy, to test their influence on electric aircraft adoption rates. The results of the analysis suggest that most of the individual policies when implemented are not enough to reach the Flightpath 2050 CO2 emissions goal. Furthermore, a strong set of policy combination was required to reach the goal. Specifically, the combination of an electricity subsidy with kerosene tax demonstrates a higher electric aircraft adoption rate than that of other combinations. On the other hand, sensitivity analysis shows that combinations with electricity subsidy display higher volatility in the CO2 emissions interval. The main reason for this sensitivity is due to the uncertainty in cost pertaining to electric aircraft development parameters.

Skin microbiome considerations for long haul space flights.

Dysbiosis of the human skin microbiome has long been associated with changes to the pH of the skin, dermal immune function and chronic skin conditions. Dermatological issues have been noted as the most prevalent medical presentation in the microgravity environment of space. The change in gravitational forces has been implicated in human immuno-suppression, also impacted by changes in the gastrointestinal-skin axis and its impact on Vitamin D metabolism, altered microbial gene expression in resident flora (leading changes in biofilm formation) and increased virulence factors in potential pathogens. There are also other stressors to the skin microbiome unique to space travel, including increased exposure to radiation, prolonged periods of dry washing technique, air quality and changes in microbe replication and growth parameters. Optimal microbiome health leads to enhanced skin barrier manufacture and maintenance, along with improved skin immune function and healing. In a microgravity environment expected to be experienced during long space flights, disruptions to the skin microbiome, coupled with increased virulence of pathological viruses and bacteria has implications for holistic skin health, astronaut cognitive function and mental health, and is coupled with slowed rates of wound healing. Scenario management for holistic skin health and restoration of microbiome homeostasis on long space flights require consideration.

The Great Modal Shift

Support to reduce and eventually eliminate the number of short haul flights in Europe and replace them with more environmentally-friendly rail connections is growing as countries look to take bolder steps to avert climate disaster

Aircraft Interior Requirements for a Good Sleep

Sleeping in long haul flights is difficult. There is noise, an upright sitting position and neighbours and crew disturb the sleep. However, there is not much information available for designers on the most important factors next to the seat that could improve the sleep quality. In this paper a co-creation session and a survey among 109 participants has been performed to study factors influencing sleep in a long-haul flight. This study shows that not only the seat is important for a good sleep, but factors like privacy, hygiene and neighbours play a role as well. The more frequent travellers experience more comfort during sleep. So, probably a good preparation is important as well.

\u201cBlessed by the algorithm\u201d: Theistic conceptions of artificial intelligence in online discourse

“My first long haul flight that didn’t fill up and an empty row for me. I have been blessed by the algorithm ”.The phrase ‘blessed by the algorithm’ expresses the feeling of having been fortunate in what appears on your feed on various social media platforms, or in the success or virality of your content as a creator, or in what gig economy jobs you are offered. However, we can also place it within wider public discourse employing theistic conceptions of AI. Building on anthropological fieldwork into the ‘entanglements of AI and Religion’ (Singler 2017a), this article will explore how ‘blessed by the algorithm’ tweets are indicative of the impact of theistic AI narratives: modes of thinking about AI in an implicitly religious way. This thinking also represents continuities that push back against the secularisation thesis and other grand narratives of disenchantment that claim secularity occurs because of technological and intellectual progress. This article will also explore new religious movements, where theistic conceptions of AI entangle technological aspirations with religious ones.

Factors Influencing Competitive Pricing for Airlines in Malaysia

The purpose of this study is to determine the factors that influenced competitive pricing for airlines in Malaysia. A particular route, Kuala Lumpur to Singapore has been selected as the case study whilst observing a comparison of competitive pricing between full service and low cost carriers. This research was derived in response of World’s Busiest International Air Routes report from OAG Aviation Worldwide that shows more than 30,000 flights frequency on average in both directions for international route Kuala Lumpur to Singapore on an annual basis. This study will try to explore the influence in competitive pricing between forecast on demand and product quality. A framework model has been proposed to determine the factors on competitive airlines pricing in Malaysia. The outcome of this study is to assist airlines to develop an effective approach for competitive pricing for passengers to choose their desired air carrier for short haul flight sectors.

Effect of Jet Lag on Brain White Matter Functional Connectivity

Background: A long haul flight across more than five time zones may produce a circadian rhythm sleep disorder known as Jet Lag. Little is know about the effect of Jet Lag on white matter (WM) functional connectivity (FC). Methods: Resting-state functional Magnetic Resonance Imaging was performed in 23 participants within 24 hours of flying and again 50-days later. Gray (GM) and WM networks were identified by K-means clustering. WM FC and Functional Covariance Connectivity (FCC) analyzed. Next, a sliding window method was used to establish dynamic WM FC. WM static and dynamic FC and FCC were compared between when participants had initially completed their journey and 50-days later. Emotion was assessed by using the Positive and Negative Affect Schedule and the State Anxiety Inventory. All subjects were confirmed to have experienced Jet Lag by the Columbian Jet Lag Scale. Findings: The static FC of WM7-GM7, and WM14-GM4, were lower after the long haul flight compared with recovery. Corresponding results were obtained for the dynamic FC analysis. FCC between the cingulate network (WM7) and several brain networks was weaken and especially precentral/postcentral network. Emotion scores were negatively correlated with the FC between the WM7 and sensorimotor related regions. Interpretation: The results of this study provide further evidence for the existence of WM networks and show that Jet Lag is associated with alterations in static and dynamic WM FC and FCC especially in sensori-motor networks. Jet Lag is a complex problem which not only related with sleep rhythm but also influence emotion. Funding Statement: This study was supported by the National Natural Science Foundation (Grant Nos. 81971595, 81771812, 81761128023 and 81621003). Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT, Grant No. IRT16R52) of China, and the Science and Technology Department of Sichuan Province (2018SZ0391) and the Innovation Spark Project of Sichuan University (No. 2019SCUH0003). Declaration of Interests: The authors have no conflict of interest to declare. Ethics Approval Statement: The study was approved by the West China Hospital Ethics Committee of Sichuan University and prior to any investigations being performed each subject gave fully informed written consent of their willingness to participate.

A TLD-Microdosimeter for aerospace usage: Results relevant to airline pilots undertook long-haul intercontinental flights during March–May 2017

During high altitude long haul flights pilots, cabin crew and passengers are exposed to enhanced level of radiation originating from cosmic ray showers (CRS), produced via the interaction of very high-energy (~GeV) primary protons with the air molecules in Earth's atmosphere. The CRS are composed of energetic particles of diverse species, i.e. neutrons, protons, electrons, muons, pions and photons. Furthermore, the magnitude of aircrew radiation exposure depends on flight altitude and duration, geographical location (latitude), geomagnetic conditions and solar activity (modulation) status. In 1990 the International Commission on Radiological Protection (ICRP) classified airline crewmembers as “radiation workers”. A miniature passive microdosimeter (LiBe-14) based on LiF (TLD700) and Beryllium Oxide (BeO) thermoluminescence dosimeter chips emulating a large volume gas-filled Tissue Equivalent Proportional Counter (TEPC) was developed by one of the authors (BM). The LiBe-14 was deployed to assess the integrated ambient dose equivalent of two commercial pilots on long haul intercontinental flights during March–May 2017. The accumulated dose equivalents of 1st (38 y, Female, 148 total block hours) and 2nd (29 y, Male, 149 total block hours) pilots were evaluated to be 565 μSv ± 105 μSv and 738 μSv ± 137 μSv, respectively. The results agreed well within ±20% of simulated data evaluated using the well-known EPCARD (European Program Package for the Calculation of Aviation Route Doses) aviation dosimetry code. The implementation of LiBe-14 Microdosimeter in routine long haul, high-altitude commercial flights for the estimation of dose equivalent, average LET and quality factor relevant to impinging cosmic radiation is recommended.

Aviation Human Factors Related Industry News

Aviation Human Factors Related Industry News

Pilot Fatigue Risk Analysis: Conceptual Study at Flight Operation of Garuda Indonesia’s Boeing 737 Pilots

Fatigue in aviation is a critical field, since it will influence many passengers’ safety. Garuda Indonesia is a Flag Carrier of the largest archipelago national, which cover three different time zones. This study aims at analyzing the airline pilot’s fatigue contributors at Boeing 737 fleet, the short to medium haul flight operation workhorse of Garuda Indonesia, which fly domestic and regional flights. While in the aviation industry, most of the human factors related fatigue research focused on long-haul pilots, since the exposure of their duties towards jet-lag. However, short-haul pilots experience of flight operation of less than 8 hours flight time per flight sector, multiple flight sectors a day, with the set of two pilots for each rotation pattern causes their elevated levels of fatigue. Classification of fatigue are; physical decline, mental decline, and rest defects. Fatigue of Garuda Indonesia’s Boeing 737 pilot is affected by; duty assignment, personal lifestyle, work environment, rest environment, unresolved stress, and illness. Finding the variables and the phenomenon can also contribute to pilot fatigue management.

Aircraft Interior Design And Satisfaction For Different Activities; A New Approach Toward Understanding Passenger Experience

Among airlines and aircraft manufacturers there is much attention for passenger experience. However, there is much literature on how the activities of passengers can be supported by the aircraft interior. The current study focuses on the need finding and requirements analysis of flight passengers. Twenty-three activities were defined based on retrospective interviews and brainstorming sessions. Respondents were asked to rate their overall perception related to the importance of each of those 23 activities on a Linkert scale, from not at all to extremely important. On a separate question they were also asked to rate their overall satisfaction by each of the same activities, ranging from not at all to extremely satisfactory. These scales were assessed for those who travel alone, together or within groups, and those who travel with kids under six years. Five of the most common cabin configurations for long haul flights were also presented to respondents, and based on their choices, seat choice behavior of each passenger type in each row was analyzed. The results show that resting and relaxing, using the restroom and sleeping were the most important activities to all passengers, while talking to neighbors and other group mates, as well as playing or working with cellphones were the least important activities. In addition, passengers' satisfaction while watching in-flight movies, thinking and observing as well as checking real-time flight status were the most satisfactory among other activities. Sleeping and in-/egress of the seat were the least satisfactory activities. Also, activities such as taking care of family are the least satisfactory in the context of long haul flight for group travelers. Group travelers' satisfaction rate by Interacting with flight attendants was also the same as that of other travelers. Seat preferences in each configuration is very similar. individual and couple travelers are similar in preferring window and window-aisle seats, while for group travelers seating together is the first priority over seating next to a window.

Improving the operating efficiency of the more electric aircraft concept through optimised flight procedures

The increasing awareness of the environmental risks and costs due to the growing demand in aviation has prompted both academic and industrial research into short-term and long-term technologies which could help address the challenges. Among these, the more electric aircraft has been identified as a key design concept which would make aircraft more environmentally friendly and cost effective in the long run. Moreover, the notion of free-flight and optimised trajectories has been identified as a key operational concept which would help curb the environmental effects of aircraft as well as reduce overall costs. The research in this paper presents a methodology in which these two concepts can be coupled to study the benefits of more electric aircraft (MEA) flying optimised trajectories. A wide range of issues from aircraft performance, engine performance, airframe systems operation, power off-take penalties, emission modelling, optimisation algorithms and optimisation frameworks has been addressed throughout the study. The case study is based on a popular short haul flight between London Heathrow and Amsterdam Schiphol. The culmination of the study establishes the advantage of the MEA over conventional aircraft and also addresses the enhanced approach to the classical aircraft trajectory optimisation problem. The study shows that the operation procedures to achieve a minimum fuel burn are significantly different for a conventional aircraft and MEA. Trajectory optimisation reduced the fuel burn by 17.4% for the conventional aircraft and 12.2% for the more electric compared to the respective baseline cases. Within the constraints of the study, the minimum fuel burn trajectory for the MEA consumed 9.9% less fuel than the minimum fuel burn trajectory for the conventional aircraft.

Approaches to the Pharmacological Management of Jet Lag.

For many years now a treatment mitigating the debilitating effects of jet lag has been sought. Rapid travel across time zones leads, in most people, to temporary symptoms, in particular poor sleep, daytime alertness and poor performance. Mis-timed circadian rhythms are considered to be the main factor underlying jet-lag symptoms, together with the sleep deprivation from long haul flights. Virtually all aspects of physiology are rhythmic, from cells to systems, and circadian rhythms are coordinated by a central pacemaker or clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN adapts slowly to changes in time zone, and peripheral clocks or oscillators adapt at different rates, such that the organism is in a state of desynchrony from the external environment and internally. Light exposure is the main factor controlling the circadian system and needs to be considered together with any pharmacological interventions. This review covers the relatively new chronobiotic drugs, which can hasten adaptation of the circadian system, together with drugs directly affecting alertness and sleep propensity. No current treatment can instantly shift circadian phase to a new time zone; however, adaptation can be hastened. The melatoninergic drugs are promising but larger trials in real-life situations are needed. For short stopovers it is recommended to preserve sleep and alertness without necessarily modifying the circadian system. New research suggests that modification of clock function via genetic manipulation may one day have clinical applications.

Car Travel-Related Thrombosis: Fact or Fiction?

The condition sometimes referred to as "economy class syndrome," and also known as "traveler's thrombosis," is a distinctive pathological condition characterized by occurrence of venous thromboembolism (VTE) in a patient who has recently experienced a long journey (i.e., ≥ 4 h). Typically, the identified travel is by airplane, but travel with other vehicles, such as trains, trucks, buses, or cars, could potentially qualify as contributing to VTE events. Although the enhanced risk of VTE after long haul flights is now widely acknowledged, albeit potentially overhyped, the risk of venous thrombosis after prolonged travel by other modes of transport, in particular, by cars, is less well appreciated. Current evidence, collected from some epidemiological studies, suggests that if any risk of VTE can be attributed to prolonged and uninterrupted car travels, and we give moderate credibility to such an association, the risk may be similar to that already proven for long haul flights. The risk is especially high in individuals undergoing uninterrupted car journeys lasting 4 hours or longer, in vehicles with a narrow seat-pitch, and in particularly would affect those with pre-existing acquired or inherited prothrombotic conditions. The putative biological mechanisms basically entail venous stasis and edema, which are often compounded by a certain degree of hypercoagulability. When these factors are combined with preexistent prothrombotic conditions, the risk may be substantially magnified. In this perspective, then, 'car thrombosis' may be regarded as a trigger rather than a risk factor for venous thrombosis. Although the current evidence is certainly not solid enough to endorse the use of general chemical prophylaxis for lowering the risk of car-related VTE, a set of possible precautionary measures, with no or very little side effects, may be suggested before planning prolonged car travels, especially for at risk individuals.

In-flight angina pectoris; an unusual presentation

BackgroundAn unusual case of typical angina which occurred on a long haul flight is presented. This case is notable as this was the index presentation, with no previous symptoms prior to this. Physiological changes at altitude can be marked, and include hypoxia, tachycardia and an increase in cardiac output. These changes were enough to expose underlying angina in our patient.Case presentationA 68 year old man presented with typical cardiac chest pain on a long haul flight. His symptoms first started 10-15 min after take-off and resolved on landing. This was his index presentation, and there were no similar symptoms in the past. Background history included hypercholesterolaemia and benign prostatic hypertrophy only. He led a rather sedentary lifestyle.A CT coronary angiogram showed significant disease in the proximal left anterior descending artery and proximal right coronary artery. He went on to have a coronary angiogram with invasive physiological measurements, which determined both lesions were physiologically significant. Both arteries were treated with drug eluting stents.Since treatment, he once again embarked on a long haul flight, and was completely asymptomatic.ConclusionThe presentation of symptoms in this individual was rather unusual, but clearly caused by significant coronary artery disease. Potentially his sedentary lifestyle was not enough in day-to-day activities to promote anginal symptoms. When his cardiovascular system was physiologically stressed during flight, brought about by hypoxia, raised sympathetic tone and increased cardiac output, symptoms emerged. In turn, when landing, with atmospheric conditions normalised, physiological stress was removed, and symptoms resolved. Clinically therefore, one should not exclude symptoms that occur with differing physiological states, such as stress and altitude, as they are also potential triggers for myocardial ischaemia, despite absence of day-to-day symptoms.

The impact of low-cost carrier on traditional airline' fares on intercontinental routes

Norwegian Airlines was one of the first airlines in the world that introduced the low cost business model for long haul flights. Low airfares this airline managed to offer for its intercontinental flights have seriously jeopardized the traditional carriers forcing them to start applying different counter strategies in order to reduce the pressure of competition. Empirical results obtained by applying regression analysis for the route from London to New York show that presence of the low cost carrier, Norwegian Airlines, exerts small, yet statistically significant influence upon reduction of airfares by British Airways which was for many years the dominant airline on this route. Moreover, the results of the model underline the importance of applying the 'seat capacity increase' strategy in British Airways' economy class, which proved to be an efficient business tool bringing good results with relatively low investments in a short period of time.

Prescriptive analytics in airline operations: Arrival time prediction and cost index optimization for short-haul flights

In this paper, we provide arrival time prediction combined with a cost index optimization model for short haul flights. Our work is based on flight data of a European network carrier. We focus on predicting the arrival time for incoming flights at two hub locations. Airlines focus on two aspects in their operations: Minimizing cost while ensuring on-time arrivals. Especially network carriers with hub connections need to ensure that incoming flights are on time for passenger, crew and aircraft transfer. The cost index is a tool for optimizing the aircraft’s speed. A high cost index implies a faster flight. The cost of time is set in relation to the cost of fuel. Today there is no model for arrival time prediction and integrated cost index optimization. We consider three different flight distances to model the impact of cost index changes on gate arrival time. With our model airlines are able to reduce the cost index without any tangible impact on their overall schedule. We conclude that the optimal cost index level heavily depends on a flight’s distance, fuel costs and delay costs. Especially for short haul flights we recommend lowering the cost index as a high cost index has limited impact on gate arrival time.