Aircraft Hangar Research Articles

Numerical Analysis for Smoke Spread in an Aircraft Hangar

Smoke is one of the most dangerous factors in aircraft hangar in case of fire. As it causes reduce in visibility and deaths due to high temperature or toxicity also prevents applying evacuation plan for workers. This study present numerical analysis for improving traditional system of ventilation system to manage smoke produced due to push-back vehicle on fire at hangar. By studying effect of changing extraction and supply rates, the number of extraction and supply fans, and the arrangement of extraction and supply fans on the visibility, temperature and air velocity at human level to insure not to exceed limits stated by NFPA 130[1] to apply evacuation plan for workers. The study is performed using Fire dynamic simulator to simulate 16 case studies in the hangar of airports in Brandenburg. The hangar has the outer dimensions of 83.40 m width and 77.60 m depth and thus an inner area of approx. 6,472 m2. The hangar has a medium interior height of approximately 18.20 m. The results show that using extraction fans with rate (ACH) double the supply rate for the traditional ventilation system gives very good results in controlling the smoke. As well as, decreasing the number of supply fans will make the smoke spread rate inside the hangar lower, which helps to control the smoke spread of fire in less time.

Becoming the Mob: Mike Brookes and Mike Pearson's Coriolan/us

Becoming the MobMike Brookes and Mike Pearson's Coriolan/us Penelope Cole (bio) People milling about, chatting. Drizzly rain. The bang of port-o-potty doors. The rustle of paper. Smells of beer, wet earth, water. Huge blue doors. More people. Headphones? Laughter. Excitement. Disquiet. Wonder. Brrrr. And then, pushing from behind, WHAT? A horn honking, WHERE? Swiveling our heads to see . . . a Van?! driving through the assembled masses? OUT OF THE WAY! Blue doors sliding open, visions of a throng of people on movie screens football fields away. That's US! And then we're in. The "play" has begun. Hangar 858, RAF St. Athan, in the Vale of Glamorgan, Wales, was the site of Mike Brookes and Mike Pearson's 2012 production Coriolan/us, produce?d by the National Theatre Wales in association with the Royal Shakespeare Company, commissioned for the World Shakespeare Festival. A conflation of Shakespeare's Coriolanus and Brecht's adaptation titled Coriolan, the action of the play (both dramatic and physical) is located predominantly in public spaces replete with crowds of supporters and/or detractors. From the beginning, the principle concept driving the production was the mobs embedded in the architecture of the two texts, which informed the scale and scope of the site and, in turn, determined the use of multimedia within the production. In this article, I explore how the aircraft hangar and installed scenic elements as well as the collective movement through the space by the audience/viewers and the performers, combined with projected images and sound piped through headphones, invited us to reimagine our (the audience/viewers') place and identity in Pearson and Brookes's world of Coriolan/us.1 The crowds of people prominent in both Shakespeare's original text, appearing in twenty-five out of twenty-nine scenes, and Brecht's adaptation, wherein [End Page 104] "the people" are the focus of the action, spurred Brookes and Pearson's interest in the plays. In the Coriolan/us program, Mike Brookes explains how this central image of the masses influenced the production. "In our imaginings, from the inception of this work, Coriolan/us was always going to unfold amongst a crowd, as it moved and flowed around the open public space of this event."2 Mike Pearson, in his article "National Theatre of Wales's Coriolan/us: A 'Live Film,'" noted how crowded the world of Shakespeare's Coriolanus is and remarked on the multiplicity of generalized public locations (battlefields, streets, marketplaces, and the like) required by the text.3 Based on these and other features found in the texts of the plays, Pearson recounts that the "decision was made . . . to regard the audience from time to time and unwittingly perhaps, as citizens, army, bystanders, film extras, etc., and to achieve the production . . . with only two Citizens and two Tribunes . . . No massed supernumeraries, no rioters, no foot soldiers to hinder the momentum of the events."4 Thus, the audience/viewers were, from the first, cast in the role of the populace of Rome, the body politic, citizens, soldiers, and rioters, to occupy, inhabit, and define the public spaces within and upon which the action takes place. Additionally, the movement of these multitudes figured in the imagining of the production. In the program notes, Brookes articulates a dynamic movement flowing through an open space, "act following act, one then leading another, the rolling consequences of our choices and reactions accumulating as they ripple on through the body and structure of a social forum constituted by all those present" (emphasis mine).5 This social forum, the various peoples of ancient Rome, was to be created, in theory and in practice, in large part by the choices in movement the audience/viewers made as they negotiated the site, physically, mentally, and emotionally, in response to the production choices, the complex choreography of the performers, and the architecture of the aircraft hangar. To accommodate the flowing movement of the imagined crowds of Rome as well as the scope of the action of the play, Brookes and Pearson sought a large, wide-open space that could be easily traversed. Brookes states, "It was always going to happen to scale. A large open place...

Acoustic detection and tracking of UAS targets

Acoustic detection using a Minimum Variance Distortionless Response (MVDR) method and tracking of Unmanned Aircraft System (UAS) targets with the MVDR results over time will be presented. The acoustic environment was complex with surf noise, wind, road traffic, air traffic, and aircraft hangar noise. The targets were gas and electric fixed wing UAS as well as electric multi-rotor quadcopters. Scenarios with the UAS target leaving, incoming, and with multiple simultaneous targets are addressed. Tracking results are evaluated through comparison with GPS based UAS ground truth tracks.

Building a floating palace [superyachts

It's A windswept frozen day in the small town of Oss where, in a colossal enclosed boatbuilder's yard, the sights and sounds of good old-fashioned metal bashing are in the air. A 50-metre-long skeletal aluminium framework forms the bones of what will become one of the most luxurious yachts the world has ever seen. For those inspired by the fabrication of big shiny things, these construction areas (the size of aircraft hangars) at Netherlands-based boatbuilder Heesen are a joy to behold. However, for those who like their superyachts sleek and finished, elegantly cruising the Caribbean main, it appears that - on the surface at least - this primer-pink carcass of a ship has a long journey ahead of it. It will be months before the client will even set foot on what is ultimately a floating private palace that displays the wealth of Croesus. Founded in 1978, Heesen is one of the world's leading brands in superyacht design and manufacture. Earlier this year, the boatbuilder scooped no fewer than three gongs at the 10th annual World Superyacht Awards. MySky (51 metres), Elena (47m) and Alumercia (37.9m) all made their ostentatious mark on the event.

Precast Prestressed Concrete Truss-Girder for Roof Applications

Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft) without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft) long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.

Tensile performance of prestressed steel elements

Prestressed steel trusses can offer efficient structural solutions for long span applications such as aircraft hangars, stadia and warehouses. In the current study, the tensile behaviour of prestressed steel elements, which comprise tubular steel members with internal prestressing cables, is investigated. The stability of the elements under prestress and the load–deformation response of the prestressed elements to the subsequent application of tensile loading are examined analytically, numerically and experimentally, with good correlation achieved between the three approaches. The benefits of prestressing, in terms of increased member strength and stiffness, are demonstrated, and optimal prestress levels are investigated.

Review: Sir Hugh Casson PRA, Making Friends

Sir Hugh Casson PRA, Making Friends Royal Academy of Arts, London 31 May–22 September 2013 Sir Hugh Casson PRA, Making Friends was a small exhibition that commemorated a man whose career spanned fifty years and included a period as president of the Royal Academy (1976–84). Curated by the architectural historian Neil Bingham, and designed by Casson’s daughter’s Dinah, the tone of the exhibition was set with the description of him as “a spirited leader and a uniting force in the arts, delighting the public and profession alike.” The approach taken to the curation was chronological and biographical. The exhibition opened with an outline of Casson’s early life and architectural training (Cambridge, then the Bartlett School in London). Next, two of the first room’s walls were devoted, one to his war work, when he served as a camouflage officer, and one to “Exhibitions and Interiors,” describing his role as director of architecture at the Festival of Britain and commissions for interiors such as on the Royal Yacht Britannia . A central block of vitrines displayed family correspondence, sketchbooks, and examples of his design work. The second room was devoted to “Architecture” and began with Casson’s prewar work as assistant to the modernist designer Christopher Nicholson on schemes for Augustus John and the patron of the surrealists, Edward James. The main focus was on the longest period of his professional life in partnership with …

Desenvolvimento de uma ferramenta computacional para a análise de elementos de membrana em concreto estrutural

Reinforced concrete elements subjected to membrane forces, i.e., elements subjected to in-plane shear and axial stresses are very common for modeling complex structures such as aircraft hangars, nuclear power plants, offshore oil platforms and long-span bridges. While the design of reinforcement for membrane elements is well adressed the same can not be said regarding the analysis of performance of these elements. Into this context, the present paper aims at providing a numerical tool developed in the Matlab platform, taking into account the “Modified Compression Field Theory”. In order to certificate the performance of the proposed tool, extensive numerical results were compared with experimental results available in the literature. The obtained results revealed that the proposed tool is very confident for the analysis of reinforced concrete membrane elements.

IDEAS IN ARCHITECTURE

1 R I D E A S I N A R C H I T E C T U R E W I T O L D R Y B C Z Y N S K I The École des Beaux-Arts in Paris, which dominated architectural education in the nineteenth and early twentieth centuries, developed a strict method of teaching building design. After being assigned a problem, the student was isolated in a cubicle without the benefit of books or external advice, and given twelve hours to produce an esquisse, or preliminary design sketch. The chief purpose of this exercise was to decide on a parti, the governing idea that the student would turn into a detailed design over the next two months. A student handbook advised, ‘‘Selecting a parti for a problem is to take an attitude toward a solution in the hope that a building developed on the lines indicated by it will give the best solution of the problem.’’ Although the esquisse is a thing of the past, the term parti has survived, for it embodies an enduring truth: great buildings are often the result of a single – and sometimes very simple – idea. When you enter the Pantheon in Rome, you take it all in at a single glance: a vast drum supporting a co√ered dome, illuminated from above by an oculus, or circular aperture. Nothing could be simpler, yet no one would describe the Pantheon as a one-liner. Finished by Hadrian in the first century a.d., it is one of the most 2 R Y B C Z Y N S K I Y PANTHEON, Rome, A.D. 126 influential buildings of Western architecture, having inspired Donato Bramante at St. Peter’s, Christopher Wren at St. Paul’s, and Thomas Ustick Walter at the U.S. Capitol. King’s College Chapel of Cambridge University, begun by Henry VI in 1446, is another building whose design expresses a singular idea: a tall space whose dematerialized walls are almost entirely stained glass. Modeled on a cathedral choir, the narrow chapel is eighty feet high and almost three hundred feet long. There is no apse, no crossing, no rose window, just a numinous, soaring space. In buildings, the idea also informs the details. While the co√ers of the Pantheon emphasize the solidity and weight of the dome and lead the eye up to the oculus, the lacy fan vaults of the Perpendicular Gothic chapel harmonize with the delicate tracery of the windows. A more recent example of a building whose design is driven by an idea is Frank Lloyd Wright’s Solomon R. Guggenheim Museum in New York. Wright started with the insight that, given the high cost of Manhattan real estate, the museum had to be vertical. He explored four schemes, one of them octagonal, and settled on a I D E A S I N A R C H I T E C T U R E 3 R F R A N K L L O Y D W R I G H T , Guggenheim Museum, New York, 1959 spiral ramp coiling around a tall skylit space. Museumgoers would take the elevator to the top of the ramp, viewing the art as they descended. It is uncomplicated in conception, yet no matter how often I go there I am always surprised – and delighted – anew. Wright kept the details in the background: the spiraling balustrade , for example, is a plain concrete parapet with a rounded top; the ramp floor is simply painted concrete. ‘‘The eye encounters no abrupt change,’’ he explained, ‘‘but is gently led and treated as if at the edge of a shore watching an unbreaking wave.’’ Another modern museum that is based on a simple idea is the Sainsbury Centre for Visual Arts at the University of East Anglia in Norwich, a building designed by Norman Foster in the mid1970s . Although the building was to house a variety of uses – exhibition spaces, a school of art history, a student cafeteria, and a faculty club – Foster accommodated them in what was basically an extremely long shed that recalls an elegant aircraft hangar. The long space, glazed at each...

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Picketing the Zeitgeist: Crisis Art

Picketing the ZeitgeistCrisis Art Harold Jaffe (bio) This guitar kills fascists. —Woody Guthrie On September 5, 1981, the Welsh group that called itself “Women for Life on Earth” arrived on Greenham Common, in Berkshire, England. They had marched from Cardiff, Wales, with the intention of challenging the decision to site ninety-six US cruise nuclear missiles on Greenham Common. On arrival they delivered a letter to the Base Commander which said, “We fear for the future of all our children and for the future of the living world.” When their request for a debate was ignored, they set up a “Peace Camp” just outside the fence surrounding the Royal Air Force Greenham Common Airbase. This surprised the authorities and set the tone for an audacious, lengthy protest that was to last nineteen years. The protesters refused to allow authorities to enter the camp, which became known as the Women’s Peace Camp and gained international recognition with imaginative images such as eggs, spiders webs. and children’s toys with which they decorated the chain link fences and contested area. In the end, the UK and US withdrew their attempt to site the cruise missiles in Greenham Common. During the Augusto Pinochet dictatorship, a number of Chilean working-class women created complex tapestries depicting the harsh conditions of life and the pain resulting from the disappeared victims of Pinochet’s repression. These tapestries, or arpilleras, get their name from the Spanish word for the burlap backing they used. Working quietly and using traditional methods, the women’s arpilleras came to have a wide influence within Chile and internationally. The tapestries preserved the memory of los desaparecidos and the dictatorship’s brutality, as well as the unemployment, food shortages, housing shortages, and other hardships of daily life attributed to Pinochet’s rule. Preserving this collective memory was itself an act of art-as-protest, but creating the arpilleras also empowered the women, many of whom experienced a liberation through their work and became involved in further protests against Pinochet’s regime. Krzysztof Wodiczko, born in Poland, emigrated to Canada, and currently lives in the US. He is particularly well known for his guerrilla projections on official buildings purported to embody public values. Guerrilla, because his images were subversive and often projected without official permission. He sought, he explained, to unmask the buildings’ existing rhetoric. One of his first projections was a swastika on the façade of the South African embassy in London during Apartheid to implicate the British government and align them with the white Apartheid regime in South Africa. And to implicate the public building itself, which presented itself as an architectural emblem of moral value. Rirkrit Tiravanija is a Thai artist. One of his installations consisted of the following: he bicycled around looking for space—empty warehouse or aircraft hangar, deserted K-Mart, abandoned Rite-Aid, haunted Burger King. He rented the space and furnished it with stoves, cooking gas, freezers, fridges, microwaves, counters, bowls, cups, glasses, plastic cutlery, chopsticks, Tupperware, folding tables, chairs. He purchased food: noodles, rice, potatoes, bread, soup, salad, tofu, fruit, green tea, bottled water, cocoa, curry spices. Comfort food. He engaged the homeless as helpers. Food prepared, he invited the homeless helpers along with the lined-up homeless to eat. Continued through the day, into the night. Clean up, close for the night. Sleep on the premises. Do the same thing for sixty days. After sixty days, he closed the space, got on his bicycle and looked for another empty warehouse or aircraft hangar, terrorized Rite-Aid, spooked McDonald’s, gutted Gap, bombed-out Home Depot. Select the space, rent it. Feed the homeless for sixty days. Close up, move on, find another space, repeat. The preceding represents four examples of creating art in times of conflict. In every instance, the art is problematic; not esthetic, as such; not even palpable in the instance of Tiravanija feeding the homeless. What is the difference between art as it is usually constructed and what might be called crisis art, or cultural activism: the use of cultural means to effect social change or a wider social awareness? Crisis artists must swallow the poison in order to...

An Alternative View: Pandemic ‘Flu and Intensive Care – an Ethical Minefield

Images of the great influenza pandemics of the past are replete with crowded hospitals the size of aircraft hangars, along with armed guards protecting healthcare workers (HCWs). It is hardly something of which the current generation have any direct memory. These images are more like fiction than recent history, but the vision of a UK pandemic in our near future is not fantasy. Scenarios of more than a million sick, infected patients with mortalities varying from 25-50% have been produced, and it is not surprising that the WHO states on its website that “economic and social disruption will be severe and that large numbers of deaths will occur.” The arrival of such a pandemic will produce ethical challenges to the way that health care is delivered and managed in the UK, of the sort not seen for decades. One does not have to envision an apocalyptic event to realise how problematical managing a pandemic would be. This government has trumpeted, for good reason, a health service that is designed to respond to individual needs and demands, and we enjoy a society that has become accustomed to an individually focused healthcare system. Even conservative modelling suggests that during a pandemic there would be 14 million infected patients in the UK.1 A proportion of these will require hospitalisation and a proportion of those hospitalised will compete for scarce intensive care beds. If a pandemic occurs, the fact that ICU beds will be scarce is certain. 2

Temperature Distribution in a Long-Span Aircraft Hangar

Long-span aircraft hangars have features which differ from other large structural systems. The temperature stresses due to temperature variations often greatly impact the mechanical performance of the structure. The paper presents an analysis of the heat transfer processes and factors which influence the temperature distribution. The AMECO-A380 aircraft hangar at the Beijing Capital International Airport was selected as a practical example to illustrate the use of finite volume analysis to calculate the temperature field taking into account meteorological conditions, solar radiation, heat convection, etc. The temperature distribution and the variation of the length of the upper and lower chords of the grid structure roof were analyzed to develop guidelines for the temperature distributions in very large aircraft hangars. The results show that the temperature effect will be large for long-span hangars, and the temperature stresses due to non-uniform temperatures should be analyzed to guarantee the structural safety of large aircraft hangars.

The English buildings book

'The English Buildings Book' is the most comprehensive single volume on English architecture for the general reader. It is a visual cornucopia and a tribute to the diversity of the English built environment, which is the richest and most diverse in the world. Where most general books on English buildings are arranged chronologically, 'The English Buildings Book' is arranged by building type and use. A series of chapters deals with distinct groups of buildings, from parish churches to railway stations. This arrangement makes the book more accessible for general readers, who will find it easier to navigate their way around a book arranged by types than one organized by historical styles. 'The English Buildings Book' is truly broad in its coverage. Over 700 buildings are described and illustrated, and they range from the architectural icons - such as castles, cathedrals, and country houses - to the less noticeable but equally fascinating buildings of our towns and villages - parish churches and meeting houses, shops and hotels, town halls and market halls, windmills and lighthouses, barns and bars. Nowhere else can such diverse coverage be found. All the buildings are represented in superb colour photographs, many specially commissioned. The photographs are arranged to enable easy comparison between buildings and each double-page spread covers a specific theme that the reader can take in at a glance or read about in greater depth. Comprehensive at it is, though, 'The English Buildings Book' is a personal book. The author and photographer, who have collaborated together for many years have made their individual choice of buildings. There are plenty of 'good examples' of each type and style, allowing the reader to follow the evolution of architecture from the Saxon period onwards. But there are also the architectural 'eccentrics' - houses shaped like aircraft hangars, mills that look like palaces, stations or cinemas in the shape of 1930s radio sets. The book is an architectural feast, from beginning to end.

ENVIRONMENTAL MONITORING SYSTEMS FOR UNDERGROUND MINES

Anglo American and its subsidiaries and associated companies own and operate many underground mines in South Africa and neighbouring countries. This paper describes the main features of “AerView”, a system developed by the company to meet the needs of those mines for robust, reliable, online and real-time measurement, display and interpretation of appropriate environmental parameters in all critical working areas. First installed over 30 years ago, the system has been progressively updated to keep pace with changing technologies and more onerous user requirements, while the user base has been broadened to operations of other mining companies as well as new applications such as warehouses and aircraft hangars. The system remains an essential component in the emergency response plans for operating sites.

A PHS pharmacist team’s response to Hurricane Katrina

The challenges and victories that a team of Public Health Service (PHS) pharmacists experienced in establishing pharmacy operations at a federal medical station and conducting outreach missions are described. The Gulf coast of Mississippi and southeast Louisiana were struck on August 29, 2005, by Hurricane Katrina, which caused widespread infrastructure damage, flooding, and loss of life. A team of 70 officers, which included 8 pharmacists, arrived on September 3 and 4 to establish a 480-bed federal medical station in an aircraft hangar at the naval air station (NAS) in Meridian, Mississippi. Numerous challenges were encountered, including identifying a secure space for a pharmacy, determining how to manage the immediate shortage of medications, devising a dispensing system specific to controlled medications, handling personal medications brought in by patients, and maintaining adequate pharmacy staffing to provide for hospital needs. Two outreach efforts were also undertaken. The first was to assist the NAS pharmacy department, which was overwhelmed with nearly 800 Navy and Coast Guard personnel who were displaced to the Meridian NAS. The second outreach effort was to augment the staff at a local free clinic in Meridian, which needed help to set up their clinic so they could handle the influx of hurricane victims who were arriving daily. A team of PHS pharmacists established a pharmacy, provided pharmaceutical care, and conducted outreach programs to aid victims of Hurricane Katrina.

FIERAsystem: A Fire Risk Assessment Tool to Evaluate Fire Safety in Industrial Buildings and Large Spaces

FIERAsystem is a computer model for evaluating fire protection systems in industrial buildings. The model has been developed as a tool to assist fire protection engineers, building officials, fire service personnel and researchers in performing fire safety engineering calculations, and can be used to conduct hazard and risk analyses, as well as to evaluate whether a selected design satisfies established fire safety objectives. While the model is primarily designed for use in warehouses and aircraft hangars, it can be modified for application to other industrial buildings. This paper describes the framework for FIERAsystem, along with its capabilities and flexibility. Individual models used to perform calculations are discussed, particularly those that calculate fire development and life hazard. A hazard analysis of an aircraft hangar is then described in detail, as an example of the types of calculations this model can perform. Methods used by the model to conduct risk assessments are also briefly described.

Welcome to the Aircraft Hangar of Babel

Welcome to the Aircraft Hangar of Babel

The Theatrical Biosphere and Ecologies of Performance

In what would a postmoderntheatrum mundi, or ‘theatre of the world’, consist? In an ironic inversion of the very concept, with the microcosm issuing a unilateral declaration of independence – or of incorporation? Or in a neo-neoplatonic recognition that it is but a cultural construct of an outer world that is itself culturally constructed? In the following article, Baz Kershaw makes connections between the high-imperial Victorian love of glasshouses, which at once created and constrained their ‘theatre of nature’, and the massive 'nineties ecological experiment of ‘Biosphere II’ – ‘a gigantic glass ark the size of an aircraft hangar situated in the Southern Arizona desert’, which embraces all the main types of terrain in the global eco-system. In the Biosphere's ambiguous position between deeply serious scientific experiment and commodified theme park, Kershaw sees an hermetically-sealed system analogous to much contemporary theatre – whose intrinsic opacity is often further blurred by a theorizing no less reductive than that of the obsessive Victorian taxonomists. He offers not answers, but ‘meditations’ on the problem of creating an ecologically meaningful theatre. Baz Kershaw, currently Professor of Drama at the University of Bristol, originally trained and worked as a design engineer. He has had extensive experience as a director and writer in radical theatre, including productions at the Drury Lane Arts Lab and as co-director of Medium Fair, the first mobile rural community arts group, and of the reminiscence theatre company Fair Old Times. He is the author ofThe Politics of Performance: Radical Theatre as Cultural Intervention(Routledge, 1992) andThe Radical in Performance: Between Brecht and Baudrillard(Routledge, 1999), and co-author ofEngineers of the Imagination: the Welfare State Handbook(Methuen, 1990).

Compensation electronics for larger dynamic range of a SQUID based nondestructive evaluation system

We have developed a compensation system for any given SQUID sensor which allows sensitive eddy current measurements above 100 Hz in the presence of strong and slowly varying background fields. High Tc SQUIDs have been used successfully in nondestructive evaluation (NDE) systems based on eddy current excitation when searching for defects in conductive samples such as aircraft parts. Due to their high and frequency independent field resolution and their excellent spatial resolution, SQUIDs provide in the case of deep lying defects—compared to other conventional electromagnetic NDE systems—a more reliable crack detection. Fast readout electronics having an unsurpassed dynamic range of up to eight orders of magnitude enabled us to perform measurements in an environment polluted with electromagnetic noise, e.g., an aircraft hangar. Nevertheless, test objects containing ferromagnetic structures with a high remanent magnetization, such as aircraft wheels or steel bolts in an aircraft wing, very often cause instabilities of the flux-locked loop operation of the SQUID. To prevent unlocking, we have developed a new background field compensation scheme. Special compensation electronics take care of slowly varying magnetic fields of up to 1 mT/s and allow us to perform eddy current measurements in the presence of slow (<30 Hz) background field variations of up to 5 mT.