Interconnected systems and networks are defining features of modern society in an increasingly complex world. They influence one another in unpredictable ways, and disruptions have the potential to create significant ripple effects. We see this in air transport operations, which rely on a complex, interconnected network of technologies, processes, and people. Industry experts are acknowledging this complexity and recognizing the need for a more resilient approach.
Resilient systems adapt to changing circumstances quickly and effectively, but they require effective communication, cooperation, coordination, and collective action from stakeholders. Neglecting these elements results in fragmented efforts, hindering the system’s ability to respond cohesively to disruptions. Conversely, paying attention to interorganizational dynamics promotes cohesive responses, helping systems adapt and thrive in the face of changing circumstances.
During a recent discussion on resilient and sustainable infrastructure, Northeastern University Professor and Founding Director of the Global Resilience Institute Stephen Flynn remarked: “There is no point being an island of resilience in a sea of fragility.”1 In air transport, that translates to the fact that airlines can no longer focus solely on their own operations; successfully transporting people from A to B requires coordination between multiple parties. Security staff, ground handlers, air traffic control, and public transport companies that get passengers to and from terminals play a vital part and have the potential to slow down (or break) the entire operation.
Clearly, we must take a more holistic view. This approach requires strengthening interorganizational interfaces; analyzing bottlenecks; and focusing on improving resilience before, during, and after a disruptive event.2
4 Elements of Operational Resilience
Achieving operational resilience involves practices and conditions that span four overarching elements: system design, system preparedness, system response, and system change. These elements work in unison to provide a comprehensive perspective on air transport resilience.
1. System Design
System design focuses on the setup of an operation and the amount of excess capacity incorporated into the network as a buffer. The larger the buffer, the better a network copes with natural operation deviations and unexpected disruptions.3
Augmenting buffer capacity enhances the potential for a resilient operation, but it can adversely affect network efficiency. Those responsible for the network must manage this trade-off.4 A good first step is to quantify maximum network utilization to create a benchmark for estimating remaining headroom.
For example, in 2017, the UK Civil Aviation Authority (CAA) conducted a review investigating the trade-off between level of punctuality and increase in flight movement.5 It concluded that runway usage at the six major UK airports had continuously increased, causing congestion. With little buffer capacity left, the network had become so brittle that diversion issues at one airport quickly affected the entire network.
The report found that no new ground infrastructure was planned for in the coming years and predicted that, with the projected increase in flight movements, the issue of limited buffer capacity would be amplified. Report authors said it would be essential to collectively work on the network’s resilience to maintain a high level of safety and meet consumer interest. Prior to that point, no shared obligations existed to tackle the resilience of the UK air transport system.
A cross-industry working group was formed and, today, the major UK-based airlines, airports, air traffic control service provider, the regulator, and other aviation stakeholders are part of the Industry Resilience Group (IRG).6 IRG’s main objective is to work on improved situational awareness through information exchange and better data collaboration.
The CAA report focused on constrained airspace and runway capacity. But as passenger numbers increased and operations ramped up during the summer of 2022, other bottlenecks that could significantly impact overall performance, such as the security clearance process, became apparent.7 Achieving resilience across the network requires a holistic approach that takes into account various processes and interorganizational interfaces.
More reviews of critical network parts provide better visibility into the true remaining buffer capacity and help stakeholders make more targeted investment decisions. For example, Ryanair invested a substantial amount of money in ground-handling equipment at its main UK hub, Stansted Airport, as quick turnaround times are a key part of its operation.8 Note that investments do not necessarily always need to involve physical infrastructure; they could include better use of available data or increased/enhanced training.
Another critical part of system design is establishing a consistent audit system. Internal processes, stakeholder interfaces, and the environment continue to change and impact the operation and its embedded buffer capacity. Changes in operations or external environment can affect risk profiles, and audits help leaders evaluate whether or not existing barriers are sufficient to mitigate emerging threats, helping to stabilize operations.
2. System Preparedness
Anticipating possible disruptions is critical to enhancing resilience.9 Close monitoring of available data is important, and a network must be able to translate early, weak signals of danger into potential safety concerns. For instance, the UK’s main air navigation service provider, NATS, compiles a list of special occasions that could impact operations. This includes state visits and sporting events with the potential to create additional stress to the network.10 This type of added demand requires additional buffer capacity, such as increasing the number of air traffic control officers on duty.
Another practical example of successful mitigation occurred around Christmas 2022. On 7 December, the UK Border Force declared a plan to go on strike from 23 December to 26 December and again from 28 December to 31 December — extremely busy travel periods. A reduction in flight schedules would have caused massive economic loss for airlines and airports, ultimately affecting thousands of people. Instead, the UK government decided that army personnel would be trained and put in place to screen passengers to limit the effects of the walkout on passenger flights.11
Of course, deploying additional resources is not always an option. In those cases, proactively reducing performance output can be a good option, especially in situations where demand for resources outweighs available supply. For example, airlines might choose to cancel flights 24 or 48 hours in advance of a severe weather event. This circumvents the need for airlines to cancel numerous flights on the day of the storm, which tends to result in large numbers of diversions, thousands of passengers stranded at airports, and crews and aircraft left out of position for the next day’s operations.
Proactively reducing flights results in more stable operations compared to planning a full flight program and reacting tactically to issues on the day. It can also be cost-effective to make deeper cuts than strictly necessary to ensure a fresh start the following day, rather than having disruptions affect operations for days. Willingness to proactively sacrifice parts of the operation for the greater good can strengthen operational resilience.
IRG is working to reinforce the connection between the UK’s weather forecast provider and air transport stakeholders to ensure that operational planning is based on up-to-date, accurate data. This helps ensure that an appropriate number of flights are cancelled in response to expected weather conditions.
3. System Response
This element of resilience combines emergency management, business continuity, disaster recovery, and several other reactive management concepts. Early detection of a disturbance helps networks contain the damage and stop the failure from spreading. In an increasingly interconnected world, organizations should establish effective communication channels to promptly inform the network and minimize operational impacts. Lack of communication can impede timely situational awareness, creating a barrier to system resilience.
Preestablished response plans are often put in place for events or threats that occur with relative frequency. The efficiency of this response hinges on the design principles described above, including redundant systems, buffer capacity, and other measures. These can minimize the impact of disruptions to network operations.
As stated in the CAA report, the network was at risk of being overwhelmed if an airport closure occurred due to increased runway use. This posed a threat because diversions could not be managed at other airports without significantly impacting operations. Therefore, in a collaborative effort, IRG produced a mass-diversion protocol for a single runway closure at any UK airport. The protocol contains a list of pre-allocated slots at several UK airports that provide air traffic control officers with an overview of the available buffer capacity at individual airports so they can efficiently distribute diverted aircraft.
For some events, no exact preplanned response is available, especially when events are so severe that internal resources of individual organizations are overwhelmed and additional resources are required. The response to these types of events usually involves multiple stakeholders, requiring an effective governance structure for communication and coordination.12
Local resilience forums in the UK can provide airports with the necessary additional resources to handle such events. The forums are multiagency partnerships comprising the National Health Service, local authorities, emergency services, and other stakeholders that airports wish to include.13 Efficient resource management and a coordinated approach among multiple stakeholders in a dynamic situation require an effective governance structure. Regular training exercises can enhance interface capabilities, promote familiarity among staff working with other entities, and generate a shared understanding of workflow.
Following severe events, the priority is to recover rapidly to an acceptable level of performance. This aspect of resilience, often referred to as “bouncing back,” emphasizes achieving a high repair rate and restoring functions promptly to reach pre-disruption performance levels.
The pandemic illustrated that some events do not permit an immediate recovery, necessitating instead a focus on survivability. During such events, the focus shifts toward survival, and organizations may adopt an emergency configuration. The pandemic provided multiple examples of this: London’s Heathrow Airport closed entire terminals to save costs, and airlines converted passenger aircraft into cargo planes, helping to transport essential goods around the world and creating a vital source of airline income.14,15
During these unprecedented occurrences, networks undergo a re-synchronization process, dramatically altering dynamics. This creates the need to reevaluate and possibly reconfigure vital connections and interfaces, emphasizing the need for an adaptable governance framework to facilitate secure and smooth adaptations during a crisis.
4. System Change
The last element of resilience involves “bouncing forward.” After recovering from a disruption, networks should seize the opportunity to review the incident and pinpoint lessons learned. This introspective process involves both contemplating potential improvements and recognizing the positive aspects, ensuring the preservation of effective practices for future events.16
Network enhancements aren’t restricted to learning from past events; they can stem from proactive measures. It is essential to note that apparent improvements in one area of the network may inadvertently produce side effects in other parts, potentially compromising the network’s stability.
Before introducing modifications, it is essential to perform risk assessments and network analyses to detect possible repercussions, and communicating these adaptations throughout the network is crucial. The UK Airspace Change Organising Group (ACOG) is a good example of this type of change; it aims to strengthen the resilience of the UK airspace in the long term.17 The UK’s airspace design was created in the 1950s and 1960s, and although the design has evolved and new airways have been added, traces of the relatively simple original design can still be seen in today’s complex UK airspace structure.18
With the number of flights expected to rise in the near future, the UK government acknowledges a need to update and redesign the country’s airspace in its Airspace Modernisation Strategy.19 Of course, such a significant transformation presents its own set of challenges. ACOG is responsible for identifying the benefits, disadvantages, and trade-offs, while ensuring effective communication with all relevant stakeholders. Although some of these changes are several years off, networks should consider them now, as implementing these changes may require considerable time. Achieving long-term adaptability is a crucial element of resilience.
Resilience is a multifaceted concept, involving system design, system preparedness, system response, and system change. Various tools and principles are available for each of those elements to support organizations and networks as they strive to become more resilient. There are multiple forums working to establish a more holistic view on the concept of resilience and promote the interorganizational element. Achieving resilience is a team effort, so organizations need to come together to work on strengthening resilience across the network.
1 “Resilient and Sustainable Infrastructure.” Council on Foreign Relations, 9 March 2022.
2 Pettersen, Kenneth A., and Paul R. Schulman. “Drift, Adaptation, Resilience and Reliability: Toward an Empirical Clarification.” Safety Science, Vol. 117, August 2019.
3 Woods, David D. “Resilience and the Ability to Anticipate.” In Resilience Engineering in Practice: A Guidebook, edited by Erik Hollnagel, et al. CRC Press, 2010.
4 Madni, Azad M., and Scott Jackson. “Towards a Conceptual Framework for Resilience Engineering.” IEEE Systems Journal, Vol. 3, No. 2, April 2009.
5 “CAP1515: Operating Resilience of the UK’s Aviation Infrastructure and the Consumer Interest.” UK Civil Aviation Authority (CAA), 7 July 2017.
6 “Report of the Voluntary Industry Resilience Group.” UK Civil Aviation Authority (CAA), December 2017.
7 Dollimore, Laurence. “No End in Sight to Holiday Nightmare: Airlines ‘Resign Themselves to Summer of Chaos’ and Heathrow Boss Warns of 18 Months of Misery — As Passengers Face More Mayhem Today with Huge Queues and Bag Collection in ‘Disarray.’” Daily Mail, 8 June 2022.
8 Burns, Justin. “Blue Handling Creation at London Stansted Already Paying Off for Ryanair.” Airline Routes & Ground Services (ARGS), 11 September 2019.
9 Dolif, Giovanni, et al. “Resilience and Brittleness in the ALERTA RIO System: A Field Study About the Decision-Making of Forecasters.” Natural Hazards, Vol. 65, October 2012.
10 Howard-Allen, Wendy. “Planning for a Busy Summer.” NATS blog, 23 May 2019.
11 Syal, Rajeev. “Uniformed Soldiers to Cover for Striking UK Border Force Staff.” The Guardian, 29 November 2022.
12 Naderpajouh, Nader, et al. “Engineering Meets Institutions: An Interdisciplinary Approach to the Management of Resilience.” Environment Systems and Decisions, Vol. 38, August 2018.
13 Civil Contingencies Secretariat. “The Role of Local Resilience Forums: A Reference Document.” UK Cabinet Office, July 2013.
14 Fox, Alison. “Inside Heathrow’s Precautions Against Coronavirus.” Travel & Leisure, 4 May 2020.
15 Horton, Will. “British Airways Removing Seats on 777s for COVID-19 Cargo While Air France Keeps Cabin Installed.” Forbes, 10 May 2020.
16 Hollnagel, Erik. “Resilience Engineering and the Built Environment.” Building Research & Information, Vol. 42, No. 2, December 2013.
17 “CAP2156C: Airspace Change Masterplan — Future Opportunities to Express Views.” UK Civil Aviation Authority (CAA), 15 December 2022.
18 Rolfe, Martin. “History Shows Why Modernising UK Airspace Is So Vital.” NATS, accessed May 2023.
19 “CAP1711: Airspace Modernisation Strategy 2023–2040, Part 1: Strategic Objectives and Enablers.” UK Civil Aviation Authority (CAA), 23 January 2023.
©2023 Fabian Steinmann. All rights reserved.