Ground Operations Research Articles

ASSESSING THE CARBON FOOTPRINT OF A DEDICATED ALL-CARGO AIRLINE: THE CASE OF CARGOLUX INTERNATIONAL AIRLINES

The objective of this study was to examine Cargolux International Airlines, one of the world’s largest dedicated all-cargo airlines, carbon footprint and to identify how it has been influenced by its route network expansion and the operation of the next-generation, Boeing B747-8 freighter aircraft. The study covered the period 2005 to 2018. To achieve the objectives of the study, an in-depth qualitative longitudinal case study research approach was used. The data that was sourced for the study was examined using document analysis. The study found that Cargolux International Airlines annual carbon dioxide (CO2) emissions increased from 2,845,000 tonnes in 2005 to 4,093, 521 tonnes in 2018. The increase in the airline’s annual carbon dioxide (CO2) emissions is due to a higher level of services, route network expansion, and an increase its fleet of freighter aircraft. Over the study period, Cargolux’s annual carbon dioxide emissions (CO2) per available tonne kilometre (ATK) exhibited a downward trend, decreasing from a high of 386.5 grams per available tonne kilometre (ATK) in 2006 to a low of 330.8 grams per available tonne kilometre (ATK) in 2018. A similar trend occurred with the airline’s annual carbon dioxide emissions (CO2) per freight tonne kilometre (FTK), which decreased from a high of 540 grams per freight tonne kilometre (FTK) in 2011 to a low of 330.8 grams per available freight tonne kilometre (FTK) in 2017. These trends were very favourable given the expansion in services and in enplaned air cargo tonnages throughout the study period. The case study revealed that the airline’s fleet rollover plan, in which Cargolux acquired a fleet of 14 state-of-the art Boeing B747-8 freighters, has resulted in the most substantial reductions in carbon dioxide (CO2) emissions. The more favourable fuel efficiency of this aircraft results in lower carbon dioxide (CO2) emissions for their operators. In addition to operating a modern fuel-efficient fleet, Cargolux has implemented a very broad range of measures and initiatives that are designed to mitigate its carbon footprint from both its flight and ground operations. 
 
 

Operation Retirement: A Four-Stage Model of Military Retirement and Transition to Civilian Healthcare Leadership

Introduction. Little research has been done on the retirement transition of military officers to second careers in the civilian sector. Even less has been done about Military Health System officers transitioning to leadership roles in the civilian sector. This study takes an in-depth look at the process of retirement from the MHS and transition to civilian leadership. Materials and Methods. The researchers conducted an interview-based qualitative study of N=28 Medical Service Corps officers who had retired one to five years prior from the MHS and started second careers in leadership roles in (non-Federal) civilian healthcare (UNH IRB #6462). Medical Service Corps officers were selected because they did not have clinical roles they could fall back on, and had to transition to leadership roles. Results. A four-stage model of retirement emerged consisting of stages similar to an offensive ground operation: Planning (preparation for retirement), Movement to Contact (job search), Attack (integration into a civilian leadership role), and Exploitation (continuing to develop a satisfactory second career going forward). Each stage presented some unique challenges to the retiree, however underdeveloped networking skills had negative impacts at each of the stages. Conclusions. A successful transition from leadership in the MHS to leadership in civilian healthcare is aided by developing networking skills, network leadership, and a professional network that extends into the civilian market well in advance of retirement.

Preliminary calculation of the landing gear of a military training aircraft

The paper presents a preliminary calculation method, which is easy to apply for pre-dimensioning the landing gear. Preliminary calculation of the landing gear includes estimating the loads on landing and determining the position of the nose landing gear and the main landing gear of a military training aircraft. Another purpose of the preliminary calculation is to ensure the stability of a military training aircraft on landing and take-off, as well as to ensure the lateral stability of the aircraft during ground operations such as taxiing, landing or take-off.

Prediction and simulation of aircraft noise in the international Eskisehir Hasan Polatkan airport (LTBY)

PurposeIn recent years, in parallel with the increasing air traffic and the number of passengers in air transport, the number of people exposed to aircraft-induced noise has increased significantly. Especially people living in the areas close to the airports are affected by noise emission during the landing, take-off, taxi and ground operations. Negative effects of noise such as sleep disturbance, lack of concentration, anxiety and high blood pressure cardiac diseases were determined directly or indirectly for human health. For this reason, examining the noise effect caused by aircraft and determining the necessary measures to be taken is very important for the sustainable development of aviation. In the International Eskisehir Hasan Polatkan Airport (LTBY), this paper aims to calculate a noise mapping following international standards in line with the directives of the International Civil Aviation Organization (ICAO). Also, Annex 8, “Airworthiness of Aircrafts” and Annex 16, “Environmental Protection Volume 1 Aircraft Noise”, which were taken at the International Civil Aviation Convention, were proposed to determine the exposure caused by aircraft noise.Design/methodology/approachIn this paper, noise levels for the day (07.00–19.00), evening (19.00–23.00) and night (23.00–07.00) period around LTBY were predicted and calculated by the use of the IMMI software according to the “ECAC Doc. 29-Interim” method for the prediction and computation of the aircraft noise.FindingsAccording to the calculated/mapped values, in the 24 hours (Lden), the noise level is 65 dB (A) and above. In the day time zone, the noise level is 63 dB (A) and above. When the calculations for the evening time zone are examined, the noise level is above 58 dB (A). When the calculations for the night time frame are examined, it is calculated that there is no dwelling that is affected by the noise level above 53 dB (A).Practical implicationsAlong with future improvements, it is recommended to be applied to other civil airports.Originality/valueTo the best of the authors’ knowledge, there is no previous research in the literature on aircraft noise mapping of LTBY. Also, unlike the software commonly used in other works in the literature, IMMI software was used in this study. Such investigations should be carried out in other civil airports in the coming years to struggle with noise emissions and noise control. If noise boundary values are exceeded, action plans should be developed for a sustainable aviation concept. Along with future improvements, it is recommended to be applied to other civil airports.

The airport ground-transportation industry during COVID-19

The purpose of this paper is to describe the airport ground-transportation industry as the integral third leg comprising the airline, airport, ground-transportation industry; the impact of COVID-19 on its operations; and how the industry is repositioning itself for the future. The paper also depicts the positive growth many of these operators were having prior to the COVID-2019 pandemic, and the types of traffic congestion along with financial concerns that were being addressed by North American airports. Like many transportation industries, airport ground transportation is comprised of asset-based and asset-light operators. The differences in the capabilities of these operators during this period of little-to-no demand are explained. Having these different capabilities will dictate the speed at which these different operations may gear back up to serve the airline travelling public. The paper also details the disproportionate number of industry drivers affected by the virus and the financial difficulties many drivers are having in this industry. Also detailed are what operators are doing to provide safe operations for their drivers and their passengers. Furthermore provided are recommended guidelines for ground operators to follow in creating a safe environment for their drivers and their passengers. Finally, the paper looks to the future and how airports and ground-transportation operators might use this downtime to plan and implement improved services as the economy rebounds to pre-2020 levels.

MODELING OF AIRCRAFT STEERING CONTROL SYSTEM WITH TRACTION ELECTRIC DRIVE BY USED AN ADAPTIVE FUZZY CONTROLLER

One of the main tasks of the last two decades is to find ways to optimize energy consumptions for aircrafts. The commercial aviation business is increasingly using environmental monitoring systems and electrical control by using AC and DC tires. One of the trends in the development of aircraft control systems is the replacement of hydraulic and pneumatic systems with electrical ones. The aerospace industry and airlines are interested in performing steering operations without major engines. This operation method allows to save fuel, reduce brake wear, eliminates towing and achieve decreasing of environmental pollution. In the future it is necessary to implement electric steering using a traction drive (TD) based on a synchronous motor with permanent magnets (PMSM). This system is powered by an available auxiliary power unit or other sources such as fuel cells or batteries. This study presents a highly efficient electric steering system as a modern solution for improving the ground operations of modern aircraft powered by main engines. The system was investigated using steering profiles for takeoff and landing. The study determined the effectiveness of its use for steering. The influence of external factors and the change of parameters of the electromechanical system of wheel with an elastic tire were investigated. The results of modeling the dynamic processes of an electromechanical system containing elastic links in the conditions of parametric perturbations confirmed the robust stabilization of dynamic control quality indicators based on the laws of fuzzy logic.

Energy Storage System Selection for Optimal Fuel Consumption of Aircraft Hybrid Electric Taxiing Systems

Aircraft taxiing is conventionally performed using the main engines' inefficient idle thrust. Therefore, in line with greener aviation, the electrification of taxiing is the most viable option to reduce emissions, noise, and fossil fuel consumption during ground operations. This article studies the potential of hybridizing the conventional electric taxiing system, which is currently driven by the auxiliary power unit, with an electrical energy storage system, comprising commercial high-energy and high-power lithium-ion batteries, for the purpose of reducing fuel consumption. Hence, a power distribution optimization is formulated to minimize fuel consumption over a typical worst case taxi-out profile. Three different energy management strategies are presented for a narrow-body airplane. The optimization is performed for the selection of off-the-shelf batteries so that their impact on fuel savings can be evaluated in the early design stage. The study showed that a wide range of savings is achievable according to the selected strategy, the added weight allowance, and the battery characteristics. Considering a 180-kg added weight allowance and covering the three investigated strategies, up to 72% of taxiing fuel is saved.

Quantitative Methods to Support Data Acquisition Modernization within Copper Smelters

Sensors and process control systems are essential for process automation and optimization. Many sectors have adapted to the Industry 4.0 paradigm, but copper smelters remain hesitant to implement these technologies without appropriate justification, as many critical functions remain subject to ground operator experience. Recent experiments and industrial trials using radiometric optoelectronic data acquisition, coupled with advanced quantitative methods and expert systems, have successfully distinguished between mineral species in reactive vessels with high classification rates. These experiments demonstrate the increasing potential for the online monitoring of the state of a charge in pyrometallurgical furnaces, allowing data-driven adjustments to critical operational parameters. However, the justification to implement an innovative control system requires a quantitative framework that is conducive to multiphase engineering projects. This paper presents a unified quantitative framework for copper and nickel-copper smelters, which integrates thermochemical modeling into discrete event simulation and is, indeed, able to simulate smelters, with and without a proposed set of sensors, thus quantifying the benefit of these sensors. Sample computations are presented, which are based on the authors’ experiences in smelter reengineering projects.

Improving the robustness of the advanced LIGO detectors to earthquakes

Teleseismic, or distant, earthquakes regularly disrupt the operation of ground–based gravitational wave detectors such as Advanced LIGO. Here, we present EQ mode, a new global control scheme, consisting of an automated sequence of optimized control filters that reduces and coordinates the motion of the seismic isolation platforms during earthquakes. This, in turn, suppresses the differential motion of the interferometer arms with respect to one another, resulting in a reduction of DARM signal at frequencies below 100 mHz. Our method greatly improved the interferometers’ capability to remain operational during earthquakes, with ground velocities up to 3.9 μm s−1 rms in the beam direction, setting a new record for both detectors. This sets a milestone in seismic controls of the Advanced LIGO detectors’ ability to manage high ground motion induced by earthquakes, opening a path for further robust operation in other extreme environmental conditions.

Research on FOD Detection System of Airport Runway Based on Artificial Intelligence

With the rapid development of the global aviation industry, the number and scale of construction of civil airports around the world are increasing. In this context, the difficulty of aviation safety assurance work has also increased. Foreign object debris on the airport runway is one of the important factors affecting aviation safety and security. Any foreign material, debris or small objects that appear on the airport runway may pose a serious threat to the ground operation safety of the aircraft. Therefore, research on FOD detection is very important.

Empirical Method for Estimating Aircraft Fuel Consumption in Ground Operations

This study proposes a novel procedure for estimating aircraft fuel burn during ground operations using aircraft trajectory data acquired from an airport surface surveillance system. A fundamental assumption employed throughout the study is that aircraft fuel burn on the ground depends on taxi phases and corresponding thrust settings. The computational process is split into three steps: (1) define a taxi phase for each data point by analyzing the trajectory data; (2) find the fuel flow index appropriate for each taxi phase of each engine type from the International Civil Aviation Organization (ICAO) Engine Emissions Databank which contains fuel flow indices for four flight status of every commercial engine; and (3) estimate the total fuel burn on the ground for each flight by multiplying the time duration at each taxi phase by the corresponding fuel flow rate. Using 24-hour surface trajectory data collected from the Airport Surface Detection Equipment (ASDE) system at Seoul/Incheon International Airport, all flights operated on the day were analyzed applying this procedure. The results indicate that suggested taxi fuel burn rates are estimated to be about 17% lower than the ICAO values. The proposed procedure is expected to be used as an alternative method for ground fuel burn estimation.

Autonomous image-based navigation using vector code correlation algorithm for distant small body exploration

This paper proposes an autonomous image-based navigation method for estimating the target-relative position of a spacecraft for distant small body exploration. The main focus is position estimation at high altitude where the outlines of a target body can be seen in images. The asteroid explorer Hayabusa2 touched down on the asteroid Ryugu with pin-point accuracy in February 2019. For this mission, the asteroid-relative position was estimated by ground operators from 20 km to 50 m above the surface of Ryugu. For the exploration of small bodies farther than the asteroid main belt, the delay of communication with Earth is unacceptably large for feedback guidance. This situation becomes worse for larger bodies because the time constant of the dynamics becomes smaller. Therefore, real-time autonomous navigation is required for distant small body exploration even at high altitude. To accomplish high-accuracy and real-time autonomous navigation, an autonomous position estimation method based on terrain-relative navigation (TRN) that estimates deviation by comparing nominal terrain information and actual terrain information is proposed. In addition to TRN, the vector code correlation (VCC) algorithm is used for the luminance comparison of terrain information. This algorithm is a type of correlation calculation method for template matching that finds the maximum correlated region in images. With the VCC algorithm, correlation can be calculated in real time via XOR operations suitable for FPGA. The estimation accuracy and processing time of the proposed method were evaluated with a comparison to those of other methods. The results show that a high estimation accuracy, similar to the image resolution, was accomplished in real time. Finally, an evaluation using flight data from Hayabusa2 shows that the estimation accuracy and processing time of the proposed method are suitable for a real mission environment. The proposed method will be a key technology for distant small body exploration.

Analysis of BDS-3 distributed autonomous navigation based on BeiDou system simulation platform

Satellite autonomous navigation is an important function of the BeiDou-3 navigation System (BDS-3). Satellite autonomous navigation means that the navigation satellite uses long-term forecast ephemeris and Inter-Satellite Link (ISL) measurements to determinate its own spatial position and time reference without the support of the ground Operation and Control System (OCS) for a long time to ensure that the navigation system can normally maintain the time and space reference. This paper aims to analyze the feasibility of distributed autonomous navigation algorithms. For the first time, a ground parallel autonomous navigation test system (GPANTS) is built. The performance of distributed autonomous navigation is then analyzed using the two-way ISL ranging of BDS-3 satellites. First, the BDS simulation platform and the GPANTS are introduced. Then, the basic principles of distributed satellite autonomous orbit determination and time synchronization based on ISL measurements are summarized. Preliminary evaluation of the performance of the BDS-3 constellation autonomous navigation service under ideal conditions through simulation data. Then the performance of autonomous navigation for 22 BeiDou-3 satellites using ISL measurements is evaluated. The results show that when satellites operate autonomously for 50 days without the support of any ground station, the User Range Error (URE) of autonomous orbit determination is better than 3 m, and the time synchronization accuracy is better than 4 ns.

Hayabusa2 Landing Site Selection: Surface Topography of Ryugu and Touchdown Safety

One of the primary goals of Hayabusa2 is to land on the asteroid Ryugu to collect its surface materials. The key for a successful touchdown is to find a promising landing site that meets both scientific and engineering requirements. Due to the limited availability of pre-arrival information about Ryugu, the landing site selection (LSS) must be conducted based on proximity observations over a limited length of time. In addition, Ryugu was discovered to possess an unexpectedly high abundance of boulders with an absence of wide and flat areas, further complicating the LSS. To resolve these problems, we developed a systematic and stepwise LSS process with a focus on the surface topography of Ryugu and the associated touchdown safety. The proposed LSS scheme consists of two phases: Phase-I LSS, a comprehensive survey of potential landing areas at the 100-m scale based on the global mapping of Ryugu, and Phase-II LSS, a narrowing-down process of the candidate landing sites at the 10-m scale using high-resolution images and a local terrain model. To verify the feasibility of a precision landing at the target site, we also investigated the landing dispersion via a Monte Carlo simulation, which incorporates the effect of the irregular surface gravity field. One of the major characteristics of the Hayabusa2 LSS developed in this study is the iterative feedback between LSS analyses on the ground and actual spacecraft operations near the target asteroid. Using the newly developed method, we chose a landing site with a radius of 3 m, and Hayabusa2 successfully conducted its first touchdown on February 21, 2019. This paper reports the methodology and results of the stepwise iterative LSS for the first Hayabusa2 touchdown. The touchdown operation results reconstructed from flight data are also provided, demonstrating the validity of the adopted LSS strategy.

Future aircraft turnaround operations considering post-pandemic requirements

Air Transportation is a major contributor to international mobility and has high requirements to ensure safe and secure operations. Aircraft ground operations are impacted significantly by the current pandemic situation so that standard operating procedures need a redesign to incorporate the upcoming sanitation requirements. In particular, the passenger boarding process is challenged with requirements for physical distances between passengers, while in addition to standard cleaning, the cabin has to be disinfected after each flight. We evaluate potential alterations of these two aircraft cabin processes with respect to a pre-pandemic reference aircraft turnaround. The implementation of microscopic approaches allows to consider individual interactions and a step-wise process adaptation aiming for an efficient operational design. We find a significant extension of boarding times (more than doubled) if the physical distance rule is applied. The new disinfection process further extends the critical path of the turnaround, so we see a high impact on airport and airline operations. To compensate for the increased workload and process times, we provide an integrated cleaning and disinfection procedure with additional personnel. Our results indicate that the pre-pandemic turnaround times cannot be maintained for the same seat load, even if the process adaptations are being implemented. However, a seat allocation scheme with empty middle-seats (seat load of 67%) and the use of an apron position (additional use of rear aircraft door for boarding) enable pre-pandemic turnaround times without additional cleaning personnel. Aircraft turnarounds at terminal positions require between 10% (with additional personnel) and 20% (without additional personnel) more ground time.

Impact of the COVID-19 pandemic on commercial airlines in the United States and implications for the kidney transplant community.

Many deceased-donor and living-donor kidney transplants (KTs) rely on commercial airlines for transport. However, the coronavirus-19 pandemic has drastically impacted the commercial airline industry. To understand potential pandemic-related disruptions in the transportation network of kidneys across the United States, we used national flight data to compare scheduled flights during the pandemic vs 1-year earlier, focusing on Organ Procurement Organization (OPO) pairs between which kidneys historically most likely traveled by direct flight (High Volume by direct Air transport OPO Pairs, HVA-OPs). Across the United States, there were 39% fewer flights in April 2020 vs April 2019. Specific to the kidney transportation network, there were 65.1% fewer flights between HVA-OPs, with considerable OPO-level variation (interquartile range [IQR] 54.7%-75.3%; range 0%-100%). This translated to a drop in median number of flights between HVA-OPs from 112 flights/wk in April 2019 to 34 in April 2020 (P<.001), and a rise in wait time between scheduled flights from 1.5hours in April 2019 (IQR 0.76-3.3) to 4.9hours in April 2020 (IQR 2.6-11.2; P<.001). Fewer flights and longer wait times can impact logistics as well as cold ischemia time; our findings motivate an exploration of creative approaches to KT transport as the impact of this pandemic on the airline industry evolves.

Deep neural network approach for fault detection and diagnosis during startup transient of liquid-propellant rocket engine

We propose a fault detection and diagnosis (FDD) method for liquid-propellant rocket engine tests during startup transient based on deep learning. A numerical model describing the startup transient for the hot-firing test of the rocket engine allows to simulate normal and abnormal situations caused by various types of faults. Datasets containing potential fault types during the engine startup have been constructed using the numerical model to train deep neural networks targeting. Actual hot-firing ground test data of a liquid rocket have been used to determine the input parameters of the model and validate the simulation results. A numerical case study on FDD for the ground operation of an open-cycle liquid-propellant rocket engine demonstrates the effectiveness of the proposed method compared to the traditional red-line cutoff.

Effect of the Swirl Intensity of Pilot Inner Swirler on the Combustion Stability of a Lean Staged Injector With a Prefilm Atomizer

Abstract Lean staged combustion can reduce the NOx emissions by prevaporizing and premixing fuel with air, which is considered the state-of-the-art solution strategy in achieving low emission in aeronautical combustors. However, lean premixed combustion is subjected to combustion stability problems, which restrict the ground and altitude operation limits of the commercial engine. In this work, the effect of the swirl intensity of pilot inner swirler on combustion stability of a lean staged injector is experimentally and numerically studied. The lean staged injector is piloted by a dual swirler prefilm atomizer. The swirl intensity of the pilot inner swirler is varied by parameterizing the vane angle as +20 deg, −20 deg, and −35 deg, with −20 deg selected as the baseline with a counterswirling design. A single sector model combustor is designed, and the nonreacting flow field and fuel concentration distributions are measured by particle image velocimetry (PIV) and kerosene planar laser induced fluorescence (kerosene-PLIF) techniques. The alteration of swirl direction from counterswirling to coswirling induces a negligible effect on flow structures, but the spray distribution changes from a solid pattern to a hollow pattern. The increase in the pilot inner swirl intensity causes a shrunk cyclone recirculation zone (CRZ) and a reduction of kerosene concentration in the central region. The influences of the pilot inner swirler angle on combustion stability are evaluated. The ignition and lean blow-out (LBO) results show that the baseline injector exhibits excellent combustion stability, while the coswirling design holds the highest ignition and LBO fuel–air ratio (FAR). In order to find out the physical mechanisms dominating the ignition and LBO processes, nonreacting numerical simulations are conducted to provide information regarding the flow structures and kerosene concentrations at ignition limits. Moreover, the ignition sequences are redefined as the radial flame propagation phase, the axial flame propagation phase, and the flame stabilization phase. The comparison of kerosene concentration along the radial and axial propagation routes concludes that the fuel enrichment in the two processes improves the ignition performance. On the other hand, the Karlovitz number of flame anchoring points in the flame rooting region is calculated to evaluate the flame stabilization characteristics. The results indicate that promoting the number of flame anchoring points and their radial range benefits the LBO performance.

Machine Learning Approach for Flight Departure Delay Prediction and Analysis

The expected growth in air travel demand and the positive correlation with the economic factors highlight the significant contribution of the aviation community to the U.S. economy. On‐time operations play a key role in airline performance and passenger satisfaction. Thus, an accurate investigation of the variables that cause delays is of major importance. The application of machine learning techniques in data mining has seen explosive growth in recent years and has garnered interest from a broadening variety of research domains including aviation. This study employed a support vector machine (SVM) model to explore the non-linear relationship between flight delay outcomes. Individual flight data were gathered from 20 days in 2018 to investigate causes and patterns of air traffic delay at three major New York City airports. Considering the black box characteristic of the SVM, a sensitivity analysis was performed to assess the relationship between dependent and explanatory variables. The impacts of various explanatory variables are examined in relation to delay, weather information, airport ground operation, demand-capacity, and flow management characteristics. The variable impact analysis reveals that factors such as pushback delay, taxi-out delay, ground delay program, and demand-capacity imbalance with the probabilities of 0.506, 0.478, 0.339, and 0.338, respectively, are significantly associated with flight departure delay. These findings provide insight for better understanding of the causes of departure delays and the impacts of various explanatory factors on flight delay patterns.

러일전쟁 지상전의 군사전략적 분석

러일전쟁 지상전의 군사전략적 분석