The normal operation of aircraft and flights can be affected by various unpredictable factors, such as severe weather, airport closure, and unscheduled maintenance of aircraft, leading to disruption of the planned schedule. When a disruption occurs, the airline operation control centre (OCC) performs various operations to reassign resources (e.g., flights, aircraft, and crews) and redistribute passengers to restore the schedule while minimising costs or time or both.
The aviation industry has become a major player in sustaining and growth of the global economy. As people become increasingly dependent on air travel, the number of scheduled flights worldwide grows every year. According to the International Air Transport Association (IATA), civil aviation passenger demand increased by 4.2% while capacity increased by 3.4% worldwide in 2019. With the increasing demand of air travel, the airline planning and scheduling has attracted attention, and most airlines employ advanced optimisation methods at each stage of planning and execution. Flight delays and cancellations have become important factors that affect passengers’ airline preferences. Consequently, national regulatory authority for civil aviation categorically mentions airline punctuality in terms of “On time Performance”. Airlines invest millions of dollars to optimise their operations and prevent delays. But what about disruptions and its management, which in other words can be termed as resilience of operations. In recent past we have seen many such examples where airline operation were disrupted due to software issues, bad weather or due to changes in rules. In this article we will look at why disruption management or recovery has become a major problem in airline operation management.
Difference in Planning and Recovery
There are many differences between airline planning and airline disruption recovery. Planning focuses on optimization, whereas recovery targets a feasible and possibly suboptimal solution that can be obtained in real time. Furthermore, recovery may be more uncertain than planning, depending on the degree and type of disruption. Flight planning commences several months before operation, whereas recovery solutions should be coordinated and implemented as quickly as possible after a disruption and last for few hours to days.
Sources of Disruptions
Flight operations is the comprehensive management and execution of all activities ensuring an aircraft flies safely and efficiently, covering pre-flight planning (schedules, fuel, weight), in-flight monitoring (weather, ATC coordination, real-time adjustments), and post-flight analysis, involving teams like Flight Operations Officers, engineers, and systems to manage logistics, safety compliance, and performance optimisation from takeoff to landing. As various consecutive flights are arranged, any disturbance in network may propagate through the operations and may result in disruption. Sources of disruptions are –
- Airline resource disruption (e.g., aircraft, crew). This type of disruption is caused by factors such as corrective maintenance due to aircraft system failures, or when crew members are absent due to illness or personal emergency.
- External environmental disruption (e.g., weather, air traffic control). Air travel is weather-sensitive. Even minor weather conditions may reduce the airport departure and arrival rates, causing flight delays. Under severe weather conditions, coercive measures such as airport closures and air traffic control are adopted to ensure the safety of passengers and airline assets.The capacity of airports and airspaces also becomes a major factor during disruptions.
Recovery operations
Flight recovery mainly comprises the following operations –
- Delaying flights. The departure time of affected flights and related flights may be delayed.
- Cancelling flights. If the allocated resources to carry out a flight are not available, or if the flight can take place but the delays would exceed a limit, the flight is cancelled. As flight cancellation incurs high costs, this operation is usually the last recovery option for airlines.
- Swapping resources (rerouting). When aircraft or crew members are not legal for the next flight, other aircraft or crew available at the same airport are substituted for the original ones to carry out the flight.
- Deadheading crew. Deadheading means that the crew is transported to another airport as passengers to operate or perform flight tasks.
- Ferrying. Ferrying means that an aircraft is assigned to an unscheduled flight without passengers. Given the high costs of such operations, they are rarely adopted.
- Speed controlling. Various studies have recently addressed speed controlling as a recovery operation that modifies the flight time to reduce the impact of a disruption and its corresponding delay.
- Passenger reallocation. If itineraries are disrupted, passengers can be reallocated to different routing (single or multiple halts) with the same origin and destination.
Multiple recovery operations can be adopted simultaneously, according to airline preferences and capabilities. According to the complexity of disruption of operations, the recovery problem is commonly separated into a sequence of subproblems that are solved in order usually, aircraft recovery is solved first, followed by crew recovery and passenger recovery or an integrated recovery plan is selected.
Aircraft Recovery
As both crew rescheduling and passenger rerouting depend on the aircraft arrangement, effective reassignment of aircraft is essential for disruption recovery. Compared with that of planning, the time horizon of recovery is relatively short, varying from hours to days. Aircraft recovery aims to reschedule aircraft routes affected by disruptions at minimum cost while ensuring that flights after the recovery period will not be affected by disruptions. In addition, aircraft should be located at specific stations at the end of the recovery period to carry out the subsequent planned flights. Thus it is modelled as a network problem with fixed starting and end points in space and time.
Crew Recovery
Crew recovery aims to find a solution with a minimum cost for reassigning the available crews to affected flights, while crews start and end at given fixed time schedule as the crew duty period is governed by regulations.
Integrated Recovery
Both aircraft and crews play important roles during recovery, with the former being the scarcest resource for airlines. Complex restrictions and the scale of the problem hinder the integrated modelling of these two resources. The integrated recovery technique considers various inputs like aircraft and crew compatibility and integrates it with passenger and passenger itinerary. The fully integrated problem still remains challenging due to its complexity and not all disruptions are alike hence developing a model or program for disruption is very difficult.
Challenges of Integrated Recovery
Enabling good disruption management solutions requires various stakeholders to share their expertise, data, and recommendation for resolving situations. The key obstacle to automated disruption solutions is successfully integrating all parts of the airline, both at a data and User Interface level.
- Workload spike: When a large volume of passenger rescheduling requests come in, the workload spikes, demanding management of a complex set of variables which are dynamic.
- Modern systems: Disruption management solutions require a large amount of information, computing power, which may not be available. Modern systems become useless when the requisite information is not available or is out-dated/old. The next question becomes how to optimise the system which has only partial data thus human intervention and experience comes in handy.
- Optimizing the Impossible: Airline network are optimised for efficiency and profit. While disruptions resolution are based on minimising the loss and delays. This makes resolving the equation impossible at times. Flight operations application vendors haven’t built recovery solutions, and recovery solution vendors haven’t built flight operations applications. Having these two entities interact meaningfully becomes a challenge.
- Communication complexity: The task of communication between the airline (and all its departments and functions) and passengers is extremely complex, critically important, and needs to be managed effectively. An effective disruption recovery solution is one that is able to help the airline navigate through these obstacles and provide a seamless information and resolution of problems by prioritising in the order of significance. This might entail swapping the aircraft with one from a later flight, or calling a reserve crew, or even creating new itineraries for every disrupted passenger.
Integrated Disruption Recovery benefits
For airlines that can create truly integrated recovery solutions, the tangible and intangible benefits are substantial :
- Improved airline productivity
- Improved quality of life for crew
- Improved passenger satisfaction
- Reduced direct operating cost
In the airlines business, service disruptions are a fact of life – no system will eliminate them entirely. But an integrated airline disruption recovery solution can do a lot to minimise the costs and the inconvenience associated with disruptions.
Way Forward
Once the disruption has been resolved, airlines should conduct a thorough review of the incident to identify areas for improvement. Reach out to affected passengers to gather feedback on their experience and address any outstanding concerns. Demonstrating a commitment to learning from disruptions and implementing necessary changes can help rebuild trust and enhance the airline’s reputation in the long run. In an industry where trust is paramount, investing in robust disruption management strategies is not just a necessity but a competitive advantage.
- Review of disruption event and follow up with passengers.
- The national regulatory authorities should also define and publish “Network Resilience” of airlines just like they do for “On Time Performance”. This will also help passengers make an informed decision before purchasing a ticket.
- Airlines should invest in Integrated Disruption Management solutions.
To conclude, effective management of airline disruptions is essential for safeguarding reputation and maintaining customer loyalty. By prioritising proactive communication, transparency, flexible rebooking options, assistance for vulnerable passengers, empowerment of frontline staff, and post-disruption follow-up, airlines can navigate disruptions with resilience.
Be safe. Fly safe.
