Ground Service Equipment Research Articles

Characteristics, sources, and health risks of inorganic elements in PM2.5 and PM10 at Tianjin Binhai international airport

To study air pollution from aircraft activity at airport and its risks to human health, we conducted an experiment near Tianjin Binhai International Airport from November 11 to November 24, 2017. The characteristics, source apportionment, and health risk of inorganic elements in particles were determined in the airport environment. The mean mass concentrations of inorganic elements in PM10 and PM2.5 were 17.1 and 5.0 μg/m3, accounting for 19.0% of PM10 mass and 12.3% of PM2.5 mass, respectively. Inorganic elements, including arsenic, chromium, lead, zinc, sulphur, cadmium, potassium, sodium, and cobalt, were mainly concentrated in fine particulate matter. The particle number concentration within the 60–170 nm particle size range was significantly higher under polluted than non-polluted conditions. A principal component analysis revealed important contributions of Cr, Fe, K, Mn, Na, Pb, S, and Zn originating from airport activities, including aircraft exhaust, braking, tire wear, ground service equipment, and airport vehicles. Based on analyses of the non-carcinogenic and carcinogenic risks of heavy metal elements in PM10 and PM2.5, there were notable human health impacts, emphasising the importance of relevant research.

Qualitative risk assessment for future hydrogen-enabled airports

Introducing hydrogen infrastructure at airports is a key element in achieving net-zero emission aviation and, at the same time, a major challenge for the aviation industry. The operational and infrastructure enhancements required to support the ground handling of alternative-powered aircraft as well as the deployment of zero-emission ground service equipment will require significant future investment and a clear roadmap for implementation. Adapting the existing operational processes and capability levels at the airport to support hydrogen-powered flight, including refuelling and safety requirements, causes challenges but also opportunities. In addition to presenting an exemplary hydrogen deployment roadmap for a mid-sized airport, the authors present a risk register and airport strategies for managing risks to the roadmap by analysing and prioritising airport requirements.

Algorithms for Smooth, Safe and Quick Routing on Sensor-Equipped Grid Networks.

Automation plays an important role in modern transportation and handling systems, e.g., to control the routes of aircraft and ground service equipment in airport aprons, automated guided vehicles in port terminals or in public transportation, handling robots in automated factories, drones in warehouse picking operations, etc. Information technology provides hardware and software (e.g., collision detection sensors, routing and collision avoidance logic) that contribute to safe and efficient operations, with relevant social benefits in terms of improved system performance and reduced accident rates. In this context, we address the design of efficient collision-free routes in a minimum-size routing network. We consider a grid and a set of vehicles, each moving from the bottom of the origin column to the top of the destination column. Smooth nonstop paths are required, without collisions nor deviations from shortest paths, and we investigate the minimum number of horizontal lanes allowing for such routing. The problem is known as fleet quickest routing problem on grids. We propose a mathematical formulation solved, for small instances, through standard solvers. For larger instances, we devise heuristics that, based on known combinatorial properties, define priorities, and design collision-free routes. Experiments on random instances show that our algorithms are able to quickly provide good quality solutions.

Analysis of Greenhouse Gas Emission From Aircrafts and Ground Service Equipment at Tribhuvan International Airport of Nepal

This paper highlights the trend of carbon dioxide emission and its reduction measure at Tribhuvan International Airport, which is the only international airport of Nepal. The landing and take-off (LTO) cycle of three-year (2016 to 2018) data were gathered from Civil Aviation Authority of Nepal (CAAN) for all types of aircrafts and fuel consumption data of each ground service equipment (GSE) were collected from Nepal Airlines Corporation (NAC). With the help of LTO emission factors published by different institutions and collected data, the emission was calculated and overall (international, domestic, helicopters and GSE) CO₂ emission in the year 2016, 2017 and 2018 was found to be 56.55, 65.66 and 71.89 Kilotonnes respectively. Upon validation of calculated emission the discrepancy of 2.59% was found. The CO₂ emission was forecasted up-to 2030 considering two scenarios namely, time series analysis and regression analysis. Lastly, for the CO₂ reduction from GSE the scenario; Electrical GSE and Construction of Aerobridge was studied and from which it was found that the CO₂ will be reduced by 80% if implemented.

A novel method for impact force estimation in composite plates under simulated environmental and operational conditions

During its lifetime, an aircraft structure is subjected to various impacts from various sources such as tool drops, hail, ground service equipment, etc. In modern composite structures, these impacts have a significant chance of generating barely visible damage (BVID) which may lead to catastrophic failure of a structure if left undetected to grow. However, BVID is difficult to detect during routine visual inspection without specialised non-destructive inspection and thus there is large interest in developing monitoring systems for estimating the location and severity of impact events. Currently, most systems and methods have been developed for controlled lab conditions and do not consider the wide range of impact parameters in real life operation (environmental conditions, vibration, impactor stiffness, angle, etc) which may severely compromise the accuracy of these methods. In this study we have explored two methods for maximum impact force estimation, deconvolution and a novel gradient method, for the purpose of reliable severity assessment in composite aircraft structures under simulated environmental and operational conditions. It is shown that both methods allow accurate and robust estimation of the maximum impact force from various cases of impacts (variation of impact energy, mass, stiffness, angle, temperature, source) using minimum initial data from a single impact case. From further testing it is demonstrated that the gradient method is robust towards the effects of impact localisation errors and noise. The gradient method also has much less computational and storage requirements and is thus more feasible to integrate with current data acquisition systems being developed for structural health monitoring. Thus, we conclude that the proposed gradient method is suitable for impact force monitoring and severity assessment in composite aircraft structures in the simulated environmental and operational conditions.

Airport buildings: A key opportunity for sustainability in aviation

The aviation industry is under increasing pressure to reduce its greenhouse gas (GHG) emissions, and advancing sustainable airport facilities is an important and highly visible way to demonstrate progress. Citizen groups and scientific reports have both highlighted the increasing share of global GHG emissions due to aviation and have called for everything from policy changes to constrain aviation emissions growth, to a movement for passengers to abstain from flying. With the social licence to operate being called into question, the aviation industry must demonstrate that it takes concerns around sustainability seriously and that it is addressing them in order to maintain public support. A common misconception exists that because aircraft emissions are so significant, sustainability efforts at airports are negligible. Airport GHG emissions are, however, substantial, stemming from energy use in buildings, ground service equipment and specialised equipment. San Francisco International Airport (SFO), to take an example, where the authors have consulted on sustainability, uses as much energy as its three neighbouring towns combined. Nor do airport environmental impacts stop at GHG emissions — airport development and operations can lead to substantial land-use changes, health impacts on millions of passengers and airport workers and noise impacts on neighbouring communities. The secondary impacts of the enormous quantity of materials used in construction of airfields and buildings can all be felt on the local, regional and global scales. Airports can best demonstrate their commitment to sustainability through reference to the United Nations Sustainable Development Goals (SDGs): a global plan of action to protect the environment while promoting the economic growth needed to lift people out of poverty and reduce inequalities between and within countries. The SDGs have received commitments of support from civil society non-governmental organisations, national, state, and local governments and private companies around the world following the most extensive public outreach process ever undertaken, involving over 3 million people. This paper explores how sustainability fits within the SDGs across four categories — energy, water, construction materials and indoor environmental quality — and presents real-world case studies where strategies addressing these topics have been incorporated.

Relative contributions of a major international airport activities and other urban sources to the particle number concentrations (PNCs) at a nearby monitoring site

In this study, the positive matrix factorization (PMF) source apportionment model was employed to quantify the contributions of airport activities to particle number concentrations (PNCs) at Amsterdam Schiphol. Time-resolved particle number size distributions in parallel with the concentrations of auxiliary variables, including gaseous pollutants (NOx and CO), black carbon, PM2.5 mass, and number of arrivals/departures were measured for 32 sampling days over a 6-month period near Schiphol airport to be used in the model. PMF results revealed that airport activities, cumulatively, accounted for around 79.3% of PNCs and our model segregated them into three major groups: (i) aircraft departures, (ii) aircraft arrivals, and (iii) ground service equipment (GSE) (with some contributions of local road traffic, mostly from airport parking lots). Aircraft departures and aircraft arrivals showed mode diameters <20 nm and contributed, respectively, to 46.1% and 26.7% of PNCs. The factor GSE/local road traffic, with a mode diameter of around 60–80 nm, accounted for 6.5% of the PNCs. Road traffic related mainly to the surrounding freeways was characterized with a mode diameter of 30–40 nm; this factor contributed to 18.0% of PNCs although its absolute PNCs was comparable with that of areas heavily impacted by traffic emissions. Lastly, urban background with a mode diameter at 150–225 nm, had a minimal contribution (2.7%) to PNCs while dominating the particle volume/mass concentrations with a contribution of 58.2%. These findings illustrate the dominant role of the airport activities in ambient PNCs in the surrounding areas. More importantly, the quantification of the contributions of different airport activities to PNCs is a useful tool to better control and limit the increased PNCs near the airports that could adversely impact the health of the adjacent urban communities.

Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing.

This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

Air quality in aircraft: A continuing debate

In this issue, we are reminded of the diverse range of indoor environments that are very different in type, function and location, and yet all aim to provide protection for occupants from the outside environment and as far as possible maintain internal conditions appropriate for their health and well being. These environments range from naturally ventilated homes polluted by use of biomass fuels to those created and maintained by advanced technology in spacecraft. While public transport via space travel may become a reality in the coming decades, currently air travel takes place in the lower and upper atmosphere and is a regular activity both for leisure and work. During 2014, commercial airlines transported 3.3 billion passengers (plus 50 million metric tons of cargo) by means of a global fleet of over 25,000 aircraft undertaking 99,700 flights per day. Within Europe, the air traffic control network handles 27,000 flights and 2.27 million passengers per day, and this is expected to grow annually, for example, the aviation traffic in Europe is predicted to reach 14.4 million flights in 2035 (50% more than in 2012). Commercial transport aeroplanes operate in an external environment that is hostile to human life. Ambient conditions outside the aircraft include very cold temperatures ( 43 C to 65 C), very dry air, too low a level of partial pressure of oxygen to sustain life, periodic episodes of high ozone, pockets of air turbulence and levels of cosmic radiation approximately 100 times higher at typical cruise altitudes than it is at ground level. The environment inside the aircraft cabin must be healthy, safe and comfortable for passengers and crew within the constraints of aeroplane design and function. The aircraft’s environmental control system (ECS) regulates these conditions, and when at high altitude, the cabin is pressurised to an altitude equivalent to between 6000 and 8000 feet (i.e. 1800 to 2400m) above sea level. The humidity of the cabin air tends to be low compared with other public indoor spaces and occupants experience continuous noise, vibration and accelerations. Aircraft passenger cabins provide the smallest available volumes per person of any enclosed public spaces. Particular health concerns associated with health travel include those that have been associated with air quality, infection, radiation, pressure (including deep vein thrombosis), ergonomics, noise and vibration. With respect to air quality experienced by the traveller, air pollution within and around airports is an issue gaining increasing prominence with respect to the impact on the health and well being of both workers and passengers as well as those living nearby. There are various sources of air pollution in an airport which include ground vehicular traffic, ground service equipment, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants (for passengers and operators), intermodal transportation systems and road traffic (e.g. passenger cars, buses, taxis and goods vehicles). The pollutants of concern involved with aircraft emissions include particulate matter (PM), nitrogen and sulphur oxides (NOx, SOx), carbon dioxide (CO2), carbon monoxide (CO), volatile organic compounds (VOCs), and ozone (O3). Exceedance of ambient air quality regulations because of emissions associated with airport activities is a factor determining expansion of existing and the siting of new airports. Passengers and crew will be exposed to these pollutants on arrival, waiting and boarding aircraft. Once on board and in flight, passengers and crew are within a very airtight structure with full mechanically controlled ventilation, and contaminants present outside will be drawn into the cabin as components of the air supply. Measurements of air quality in cabins of aircraft preparing for take-off and taxiing following landing have been shown to have elevated levels of pollutants associated with fuel combustion, such as ultrafine particulates, compared with concentrations measured during flight when the intake air is not polluted by these components.

A Fast Heuristic for Airport Ground-Service Equipment–and–Staff Allocation

With the recent increase of air traffic, major airports become more and more congested: sensible delays may be caused by ground operations, and problems related to the efficiency and the safety of the apron area assume more and more importance. In this paper, we consider the problem of determining an efficient allocation of ground service equipment and staff to aircraft standing on the apron, as emerged in the framework of the European sponsored project “Integrated Airport Apron Safety Fleet Management – AAS”. After providing a mathematical formulation for the problem, we suggest a fast sequential heuristic to be integrated in the real time dispatching decision support systems normally adopted in modern airports. The procedure has been applied in the AAS context, showing to be able to improve efficiency of handling operations.

Ground vehicle blunt impact damage formation to composite aircraft structures

Composite aircraft structures such as fuselage and wings are subject to impact from many sources. Of particular interest are impacts which can impart severe damage that is difficult to visually detect, or is even not visually detectable. Such damage modes include delamination, separation/delamination of stringers and stiffeners from skin, and fracture of internal stiffening components such as stringers and frames. Extensive damage can be produced by blunt impact sources involving wide-area contact, which reduces the propensity to leave visible signs that damage has formed, especially with high-strength composite outer skin. Ground service equipment (GSE) is a realistic and oft-occurring source of blunt impact damage due to: (i) the interactions between GSE and aircraft typically involving a soft rubber bumper material, (ii) the close proximity with which GSE operate around aircraft, and (iii) the high mass of GSE involves very large impacting energies despite their slow speeds. Blunt impact damage can produce both local and non-local damage since, as the contact area increases, higher energy levels are involved for blunt impact damage to occur. Therefore, inspections to find damage from GSE impact events require that locations relatively far away from the impact sites must also be inspected.

Effect of impactor radius on low-velocity impact damage of glass/epoxy composites

With composites finding increased use as primary structures in commercial aircraft, it is necessary to understand the development of damage when a laminate is subject to low-velocity impacts from a variety of sources, which often occur during normal service operations and routine maintenance. In particular, contact with ground service equipment can present a blunt impact to the composite structure. Therefore, the effects of bluntness of an impactor are of interest as this is related to the development of any internal damage in the laminate, or even the surrounding structure, and also affects the visual detectability of an impact event. The objective of this investigation is to determine the effect of impactor radius on the impact damage resistance of composite panels. A low-velocity pendulum impactor was used to strike 200 mm2 woven glass/epoxy composite plates of 3.18 and 6.35 mm thickness. Hemispherical steel impactor tips of radius 12.7, 50.8, and 152.4 mm were mounted to a piezoelectric force sensor which measures the contacting force history during the impact event. Distinct threshold energy levels defining the onset of delamination and backside fiber breakage have been measured to increase significantly with increasing impactor tip radius due to development of higher contact area.

Low-Velocity, High-Mass, Wide-Area Blunt Impact on Composite Panels

Impact damage caused by ground vehicles and equipment colliding with the structural components of aircraft is a significant source of damage to commercial aircraft that may go unreported. Most common are blunt impacts from ground maintenance and service vehicles and equipment with attached elastomeric bumpers that protect the aircraft to some degree but may not leave externally visible evidence of an impact. This research examines the types of impact threats to a composite airplane fuselage, impact testing of composite specimens that simulate airplane fuselage specimens, and the visible detectability of the damage. The test program has two distinct aspects: (a) prediction through analysis and (b) small- and large-scale quasistatic indentation testing.

Airport sustainability with a positive impact on the bottom line: The Minneapolis-St. Paul International Airport experience

Airports’ interest in sustainable or green initiatives has grown around the world. An effective approach should include quantifiable onsite environmental enhancements rather than simply focusing on purchasing conservation credits. Done correctly, sustainable projects can benefit the bottom line rather than result in additional costs. Minnesota is located in the upper Midwest region of the USA. Home of the Mississippi River headwaters, it is also known as the Land of 10,000 Lakes. Public policy has historically favoured protection of natural resources, and it is no accident that this state's largest airport has also had an aggressive focus on environmental issues. The Airports Council International North America defines sustainability as ‘a holistic approach to managing an airport so as to ensure the integrity of the economic viability, operational efficiency, natural resource conservation and social responsibility of the airport’. This philosophy can serve to describe the approach that Minneapolis-St. Paul International Airport (MSP) took to its recent US$3bn expansion programme. Documented air and water quality improvements were made at MSP even as significant infrastructure growth took place. A long-term partnership with local utilities has yielded impressive rebate dollars and resulted in additional efficiencies that now shave US$1.04m from annual electrical and natural gas bills. Further improvements are being considered in the areas of lighting systems, low-emission ground service equipment, power generation and other key areas.

Proactive Mitigation of PCTFE-Related Ignition Hazards in Oxygen Systems: II. Testing of Inventoried “At-Risk” PCTFE Parts and Hazard Analyses of Corresponding Ground Service Equipment at the Kennedy Space Center

Abstract Revelations of excessive property variation in polychlorotrifluoroethylene (PCTFE) semifinished and finished parts led to concerns that leaks or part failure could occur in service, possibly leading to catastrophic component or system failure by flow friction and/or kindling chain mechanisms. Such concerns led to the issuances of an internal Kennedy Space Center (KSC) Problem Advisory and a Government-Industry Data Exchange Program Materials Advisory on PCTFE. The advisories led to an engineering analysis review of PCTFE-containing ground support equipment used in “at-risk” high-pressure oxygen and air systems at KSC Representative PCTFE replacement parts used in “at-risk” systems were removed from inventory and tested. Tests included determination of (1) dimensional stability by thermomechanical analysis and metrology, (2) percent crystallinity by specific gravity, and (3) the effect of annealing on engineering tolerances. While dimensional instability was determined not to be a major issue in existing inventories, establishing traceability back to the semifinished article (starting rod or sheet stock) was often not possible. Percent crystallinity varied widely depending on part origin and thickness. Annealing was found to lead occasionally to out-of-tolerance parts. The pneumatic impact ignition threshold of PCTFE in enriched air was also determined at pressures up to 41.4 MPa. Results show that ignition does not occur at ambient oxygen concentrations. Last, hazard analyses were performed on “at-risk” systems. Two problematic designs were discovered, but based on operational histories, a recommendation was made to redesign or repair and replace on a noninterference basis.

Restricting Use of Reverse Thrust as an Emissions Reduction Strategy

As more metropolitan areas approach “nonattainment” status for ozone, air pollution at airports is becoming an increasingly important topic. Most proposed emissions reduction strategies target passenger automobiles and airport ground service equipment (GSE). At many airports, the future growth in oxides of nitrogen (NOx) emissions from aircraft is likely to offset any reduction achieved from GSE or passenger vehicles. In some metropolitan areas, airports may be responsible for as much as 10% of the regional NOx. As a result, other alternatives are needed for emissions reduction at airports. Reverse thrust is commonly used along with wheel brakes to slow aircraft during landing and to “power back” aircraft away from a boarding gate. Currently, air pollution emissions generated during reverse thrust are not included in airport emissions inventories. Because the majority of aircraft NO, emissions occur off-airport during climb out and approach, reverse thrust can be responsible for an additional 15% or more of the on-airport NO,. Because this additional NOx is emitted over a relatively small area, it can create significant air quality impacts in the vicinity of the busiest airports. An attempt is made to quantify the air quality effect of NOx emissions produced during reverse thrust, using Dallas-Fort Worth International Airport as a case study. The significance of the airport’s emissions from a regional standpoint and state implementation plan photochemical grid modeling are addressed.

Improvement in Ground Service Equipment

ONE of the most fortunate factors in hydraulic oil filtration is that in recent years the manufacturers and users have recognized its genuine importance. The need for constant improvement in the standard of cleanliness of hydraulic oils has resulted from increased sophistication of the system concerned, and has certainly posed problems for the manufacturers of filtration equipment.