UK Airspace Research Articles

Enhancing air traffic operational efficiency by reducing network scale

The growing demand for air travel has led to the saturation of air traffic networks. Conventional methods of adding routes to alleviate congestion and reduce delays may not achieve the desired effect and even degrade system performance. In this paper, we explore the application of Braess’s Paradox in the reduction of air traffic networks. This counterintuitive phenomenon shows that adding new connections to a network can actually increase the overall network pressure. This study uses Hidden Markov methods and the Viterbi algorithm to match air traffic flow with routes, a machine learning approach and a mathematical method to construct cost functions for flight time and traffic volume, and finally uses genetic algorithm and the A* algorithm to detect Braess’s Paradox edges. We uses ADS-B data from the busy month of July 2019 for a case study of the air traffic network over the UK airspace. The results show that Braess’s Paradox is also applicable to multi-flight level air route networks. Removing such network edges can improve system performance. In one day’s case, the total flight time of the day’s traffic volume decreased from 11509.24 minutes to 10459.97 minutes. This equates to an average savings of 4.99 minutes of flight time per flight, which is significant in controlling delay performance.

Respite from aircraft noise: high-level overview of journey on building our knowledge

Most UK flight paths were designed decades ago, at a time when aircraft and navigation were much less sophisticated than today. A nationwide airspace modernisation programme is therefore underway across UK airports. The Government has embarked on its airspace modernisation strategy with its overall objective to deliver quicker, quieter, and cleaner journeys and more capacity for the benefit of those who use and are affected by UK airspace. The UK's Airspace Modernisation Strategy is part of ICAO's Global Air Navigation Plan. For this process, Anderson Acoustics Ltd (funded by Heathrow Airport Ltd) are consolidating current knowledge on respite, particularly in relation to Airspace design and this paper will report on progress. The work intends to continue the journey towards understanding respite and its effective implementation, linking together past, current, and potentially future activities, providing timelines, signposting to other reports and work. It explores the key questions around the concepts and implementation of an effective respite strategy. It will present a high-level overview of the journey to date on building our knowledge on respite, and uses this information to present a summary of the key elements to consider for appraising options in the ACP programme when designing for respite.

Health impacts of aircraft noise - a UK communities' perspective

UK Air Navigation Guidance regards 51dB LAeq16hr for day time noise and 45dB Lnight for night time noise as the levels at which aircraft noise annoyance occurs. WHO guidelines (2018) concluded that health effects can occur at lower levels of 45 dB Lden and 40 dB Lnight. Current policy recognises that noise annoyance can occur below 51dBLAeq yet it is not known how many people around UK airports may be adversely affected at these lower levels. This paper will seek to estimate the population size impacted by aircraft noise below 51dB LAeq around Heathrow airport. It will also seek to provide an international comparison of the noise policies of different airports in Europe and globally, the size of the population impacted and the minimum threshold for the onset of health effects. The most radical changes in UK airspace history will take place in the next decade. If more people are adversely impacted by aircraft noise at lower levels then this has significant ramifications for the cost benefit analysis of airspace changes. It is crucial that communities can understand the full health impacts of the proposals.

A New Model for Nowcasting the Aviation Radiation Environment With Comparisons to In Situ Measurements During GLEs

AbstractSignificant increases to the atmospheric radiation environment are recorded by a network of ground level neutron monitors as ground level enhancements (GLEs). These space weather phenomena pose a risk to aviation via single event effects in aircraft electronics and ionizing dose to passengers and crew. Under the UK Space Weather Instrumentation, Measurement, Modeling and Risk programme, we have developed a new model to provide nowcasts of the aviation radiation environment, including both the galactic cosmic ray (GCR) background and during GLE events. The Model for Atmospheric Ionising Radiation Effects (MAIRE+) uses multiple data sources to characterize primary GCR and GLE particle spectra and combines these with precalculated geomagnetic and atmospheric response matrices to predict particle fluxes from ground level to 20 km altitude across the entire globe. Two European neutron monitors (located at Oulu in Finland and Dourbes in Belgium) are used as the primary indicators of GLE intensity in order to maximize accuracy over UK airspace. Outputs from MAIRE+ for the historical GLEs in September and October 1989 are compared to recalibrated empirical data from a solid‐state detector that was carried on Concorde in that period. The model will be hosted in the UK and will provide additional capability to the Met Office Space Weather Operations Center (MOSWOC).

Fireless, burning smell driven, mayday landings of commercial aircraft as a mechanisms of motion in MIRCE Mechanics

According to Knezevic the purpose for the existence of any functionable system is to do functionability work. The work is done when the expected measurable function is performed through time. However, experience teaches us that expected work is frequently beset by the occurrences of undesirable interruptions like component failures, natural phenomena or human actions, some of which result in hazardous consequences. MIRCE Mechanics is a body of knowledge that focuses on the scientific understanding and description of the mechanisms that generate undesirable in-service interruptions. Thus, the main objective of this paper is to examine the mechanism that generated undesirable in-service interruption to 32 flights, on 16th October 2017, within UK airspace. After fireless burning smoke/fumes were felt in their cockpits the flight crew went to oxygen and declared either a PAN-PAN or a MAYDAY landing. The first event took place around 0622 during departure from Liverpool causing the aircraft to declare mayday landing and return back to land. It was followed by clusters of affected aircraft in the Channel Islands, Liverpool, Manchester and London, later in the day. Although this is one of an extremely rear observed event, its mechanism had to be understood, as if repeated, it will generate the motion of an aircraft through MIRCE Functionability Field and impact its functionability work done and resources consumed. Inspections of aircraft involved and the analysis of the meteorological conditions in Europe have revealed that the burning smell did not result from a failure of any component, but it was as a result of smoke and dust carried in the atmosphere from North Africa and Iberia. Satellite imagery from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) verified this theory. Potential actions for reducing the impact of this functionability mechanism are presented.

‘Riskscapes’ as a heuristic tool for understanding environmental risks: The Eyjafjallajokull volcanic ash cloud of April 2010

This article looks at the 2010 ash cloud event associated with eruption of Eyjafjallajokull volcano in Iceland through the lens of the actor network theory. Using this theory the shifting assignment of responsibility for the impact of the ash cloud can be traced among the various actors involved in the network focus on UK airspace. Mapping the relations between actors, in terms of their nature and strength and how these change as the event unfolded can help to analyse the changing power relations and activation of relations to align the network. Understanding the activation of such links under the stress of an extreme environmental event and the network alignment it precipitates could have important implications for managing environmental risks.

Calthorpe Park School joins the space race

The sky really is the limit for Calthorpe Park School pupils who have joined the space race. Pupils have designed equipment and programmed technology to gather weather information and to capture the curvature of the Earth through photographs and video footage using a helium filled weather balloon. An insulated capsule, containing a high-resolution camera, GPS tracking equipment and weather measuring sensors was sent up into the edge of ‘near space’—an altitude of over 32 000m (104 000ft). Calthorpe Park's STEM Club consisting of over 40 keen pupils and under the guidance of staff members Donna Wilson, David Lugg and David Hainsworth had designed and built this amazing project. The balloon needed approval from the Civil Aviation Authority to pass through UK airspace and due to Fleet, Hampshire and the surrounding area being located on the main Heathrow Airport flight path so was launched from just north of Newbury, Berkshire. Working closely with PhD students from Southampton University's Spaceflight Association the balloon was tracked throughout its flight and eventually landed near Alresford, Hampshire town centre. In fact it actually landed 5m up a tree in a local resident's garden but was successfully retrieved with the help from some interested neighbours. Pupil Matthew, aged 13 said: The science behind our balloon launch was truly amazing. The balloon was 2.5m in diameter when launched and it carried a parachute and payload below it—giving it a total length of about 30m. As it rises the outside pressure decreases which leads to the helium within the balloon expanding, causing the balloon to stretch. The balloon is made of a form of latex and is incredibly stretchy, however as it enters space it gets to a point where it cannot stretch any more and bursts. The parachute then brings the payload consisting of our camera, along with GPS and weather sensors back to earth. We were all extremely pleased that our balloon had reached a height of 32km above earth, high enough to see and record the curvature of the earth. To put that in context Felix Baumgartner's jump from space in 2012 was from a height of 39km. Pupil Jack, aged 12 said: it was one of the most enjoyable and interesting projects I have ever been involved with in STEM Club. My role was to go out in the school minibus along with other pupils and my teacher and launch the balloon. We then spent four hours tracking the balloon using GPS technology until it returned to earth. Fellow pupils had set up mission control in my school's library and were also tracking it and analysing feedback from the weather sensors such as ascent rate, temperature and pressure changes. Southampton University, who were helping us launch the balloon, set up a live internet stream so our mission control could watch us launch the balloon live. It was great when we managed to retrieve the payload and our camera and analyse the video footage. We had put our STEM club mascot on the outside of the box dressed in a school jumper and that can be seen in our photos. Video link to balloon flight can be seen here: https://www.youtube.com/watch?v=-TdMtXLq56I

April 2010 UK Airspace closure: Experience and impact on the UK’s air-travelling public and implications for future travel

Ash emitted from the Eyjafjallajökull Icelandic volcano resulted in the closure UK’s airspace in 2010. This research highlights passengers experience throughout the crisis and it is impacted on their wellbeing. Analysis of a survey shows that just 90% of respondents highlighted the failure of airline, travel agencies and/or government to provide timely and appropriate information. The airspace closure also caused adverse health impacts, with 79% of respondents highlighting this as a concern. Although passengers were greatly inconvenienced and had a negative experience, seventy-nine percent of respondents indicated that the crisis had little or no impact on their decision to fly in the future.

Reconceptualising spaces of the air: performing the multiple spatialities of UK military airspaces

This paper seeks to unpack the complex spatialities of UK airspace, looking beyond traditional civil aviation classifications to focus specifically on the spaces used by military aviation in the UK context. It argues that UK national sovereign airspace should not be viewed as a single homogenous entity, but instead must be reconceptualised as a plethora of multiple, vertically and horizontally, overlapping airspaces that can be activated or deactivated according to need. The paper employs a performativity‐based framework that highlights specifically how these spaces are identified and named, to illustrate how these multiple military airspaces are actively performed. Within this it focuses on analysing the citational and iterative actions of professional airspace managers working within the UK Civil Aviation Authority and Royal Air Force. The paper makes extensive use of documentary sources and interviews with key personnel to illustrate how the airspaces above the UK are brought into being through the actions of these actors and how these operations can be seen as part of a wider enactment of militarism’s control over space.

From ‘Our Air Is Not for Sale’ to ‘Airtrack’: The Part Privatization of the UK's Airspac

Air traffic in the UK has increased rapidly in the past two decades and is forecast to grow at a rate of 4.3% per annum between 1998 and 2020. The failure to develop the air traffic system in order to cope with this growth has had undesirable consequences, e.g. a rise in flight delays and near misses. Given the investment required in air traffic control systems to cater for this growth, the UK government in 2000 part privatized the National Air Traffic Services (NATS), the body in charge of the UK's airspace in a public–private partnership (PPP). The UK Airline Group acquired 46% of NATS and effective operational control, though the government retains a share in NATS and safety regulation is in the public sector. However, serious doubts about safety were raised during the debate on the PPP. Similar moves towards a commercial operation (i.e. corporatization) of air navigation services have been made in New Zealand and Canada over the past decade and these provide useful insights into the results of the corporatization process. This paper analyses the main issues surrounding the part privatization of NATS. First, it highlights the experience from New Zealand and Canada of the major issues involved in corporatized air navigation services in six different categories: funding, new technology and project management, safety, pricing regime, international opportunities, and customer responsiveness. The likely impacts for NATS given the lessons from New Zealand and Canada are considered. The UK government's provisions for the PPP and their implementation in the post‐PPP NATS are then outlined for these six categories. Finally, the 11 September 2001 terrorist attacks have had major impacts on air travel and their consequences for NATS in the six categories are highlighted. This paper concludes with some of the issues that need to be addressed to ensure the success of the PPP for NATS.

A Trend Analysis of Air Traffic Occurrences in the UK Airspace

The volume of air traffic has increased considerably in the United Kingdom in recent decades and with further predicted increases, there is concern that safety is not compromised. In the UK, the number of occurrences is a key safety performance indicator. An occurrence can be thought of as a failure in the chain of operations in the air traffic system. Some of these occurrences result in a loss of separation between aircraft, varying from a slight loss of separation posing no danger of collision to a very serious loss with a significant risk of collision, known as an airprox. However, in the UK this definition is extended to include controller overload that does not necessarily involve a loss of separation. This paper analyses recent occurrence trends in the UK airspace attributed to air traffic control during the period 1998 to 2000 using data from the Civil Aviation Authority and the United Kingdom Airprox Board. The results indicate a decline in the rate of occurrences over the period 1990–1999 due to safety aids on board aircraft and in control rooms. Furthermore, the different conditions under which airproxes occur have been explored and observations made on duration and causes of controller overloads.

Aircraft airworthiness certification standards for civil UAVs

AbstractThe CAA has recognised the need to develop civil standards for unmanned aerial vehicles (UAVs). Accordingly the CAA Directorate of Airspace Policy has published the document ‘CAP 722 – Unmanned Air Vehicle Operation in UK Airspace – Guidance’, (which can be accessed via the CAA website — http://www.caa.co.uk/docs/33/CAP722.pdf). The document itemises the top-level military and civil regulations which impact upon the operation of UAVs in the UK. One of the items listed within the document is ‘Civil Certification’ of UAVs. This particular aspect is the responsibility of the Design and Production Standards Division, (D&PSD), of the CAA Safety Regulation Group. The purpose of this paper is to present and explain the current position of D&PSD regarding the appropriate design standards to be applied for the civil certification of the airworthiness of UAVs.This paper presents the CAA position that UAVs should be granted permission to fly by qualifying for certificates of airworthiness, by demonstration of compliance with defined airworthiness standards comparable to, and derived from, those applied to manned aircraft. The paper also presents a method for determining, to a first approximation, the level of airworthiness standards which should be applied to any particular design of UAV by reference to the existing codes of airworthiness requirements for manned aircraft.

Aircraft airworthiness certification standards for civil UAVs

AbstractThe CAA has recognised the need to develop civil standards for unmanned aerial vehicles (UAVs). Accordingly the CAA Directorate of Airspace Policy has published the document ‘CAP 722 –Unmanned Air Vehicle Operation in UK Airspace – Guidance’, (which can be accessed via the CAA website — http://www.caa.co.uk/docs/33/CAP722.pdf). The document itemises the top-level military and civil regulations which impact upon the operation of UAVs in the UK. One of the items listed within the document is ‘Civil Certification’ of UAVs. This particular aspect is the responsibility of the Design and Production Standards Division, (D&PSD), of the CAA Safety Regulation Group. The purpose of this paper is to present and explain the current position of D&PSD regarding the appropriate design standards to be applied for the civil certification of the airworthiness of UAVs.This paper presents the CAA position that UAVs should be granted permission to fly by qualifying for certificates of airworthiness, by demonstration of compliance with defined airworthiness standards comparable to, and derived from, those applied to manned aircraft. The paper also presents a method for determining, to a first approximation, the level of airworthiness standards which should be applied to any particular design of UAV by reference to the existing codes of airworthiness requirements for manned aircraft.

Development and application of a human error identification tool for air traffic control

This paper outlines a human error identification (HEI) technique called TRACEr—technique for the retrospective and predictive analysis of cognitive errors in air traffic control (ATC). The paper firstly considers the need for an HEI tool in ATC, and key requirements for the technique are noted. The technique, which comprises a number of inter-related taxonomies, based around a simple cognitive framework, is then described. A study concerning a real-world application of TRACEr is outlined—the evaluation of several options for reduced separation minima in unregulated UK airspace. In this study, TRACEr was used predictively and retrospectively, looking forward to pre-empt potential problems and looking back to learn from experience. The paper concludes that TRACEr is a valuable aid to design, development and operations in UK ATC, and has indeed been used as a basis for further applications in ATC both in Europe and the USA.

Reliability Performance in GPS Receivers and the Nature of Their Failures: Planning to Live with Realistic Failure Rates in Satellite Navigation System Receivers

This paper and the following three papers were presented at the Institute's NAV-96 Conference, “Global Navigation — Where are we now?” The Conference was held in London In November 1996. Copies of the full proceedings may be obtained on application to the Director, price £35 for members and £50 for non-members.The National Air Traffic Services (NATS) in London require data on the performance likely to be achieved by the navigation system on board aircraft flying in UK airspace. To that end the performance of three different GPS receiver types (all designed for aviation use) have been examined. This paper details the result of that work. The achieved Mean Time Between Failures (referred to here as ‘Outages’) MTBO is presented along with the nature of some of the failures that have been encountered. The paper concludes with the operational implication of the findings.

Safety Topics

REFLECTING widespread concern over the maintenance and where possible, the improvement of safety standards, the annual report of the Civil Aviation Authority (CAA) makes these topics a central theme. The progress made in recent years towards improving the safety of air traffic control (ATC) has been maintained, in particular the number of public transport aircraft involved in risk‐bearing airmisses fell from 45 in 1977 to 16 in 1985 and remained at that level in 1986. Because traffic levels continued to rise in the latter two years, however, this represents a small improvement from 2.9 per 100,000 hours flown in 1985 to 2.8 in 1986. The comparable figure for 1977 was 11.3. In the accompanying illustration is the three‐year moving average of civil aircraft in risk‐bearing airmisses within UK airspace. Some £125 million has been spent over the last five years on re‐equipping the system, including new radars, new navigational aids and new landing systems. New computer equipment, incorporating for the first time a conflict alert capability, has also been installed at the Oceanic ATC Centre at Prestwick. Over the next five years, £200 million is intended to be spent on more radar improvements and upgrading facilities at the London Air Traffic Control Centre (LATCC) at West Drayton as well as the installation of a new central computer for which detailed design studies are well under way.