Ground operations can be a major contributor to flight delays, which can lead to dissatisfied passengers and additional costs for airlines. A number of technological solutions have been developed to improve the efficiency of ground operations and minimize delays.
Airlines are constantly striving to improve operational efficiencies, often by focusing on methods for reducing in-flight fuel burn and related costs. Another area that can optimize operations is on the ground, between flight sectors. Typical ground operations and turnaround processes are discussed here. Some of the solutions and strategies available for optimizing ground operations processes, thereby improving rates of aircraft utilization, are identified.
Aircraft turnaround process
WheelTug defines the time an aircraft spends on the ground between an arrival and its next departure, in terms of two sub-categories: total ground time (TGT) and turnaround time (TAT). TGT covers the entire period from touchdown to the next take-off, including the time required to taxi-in and out. TAT covers the onblock, off-block period, or the time taken between parking on the stand and starting pushback for the next departure.
“There are five main categories of tasks in the turnaround process,” says Martin Harrison, global managing director, airlines, aerospace and MRO at ICF. “These are: disembarkation;
servicing; security checks; boarding; and pushback/air traffic control (ATC) clearance. Each category features multiple sub-tasks. For example, servicing includes cleaning, catering and refuelling.” easyJet lists its main turnaround functions as: customer disembarkation; baggage unloading; cabin tidy and security check; customer boarding; baggage loading; refuelling; water and waste servicing; baggage and customer reconciliation; and flightcrew
preparation. It says that these task groups are broken down into 360 different subtasks. According to easyJet’s procedures, the turnaround period finishes once all doors and holds are closed, the parking brake is off and the aircraft is moving at more than three kilometres per hour (kmph), either under its own power, or by being pushed back by a tug. In common
with some operators, easyJet does not consider the pushback process as part of the turnaround, but efficiency gains in this area can still bring benefits since they
could reduce TGT. WheelTug suggests that airlines have not previously focused
on improving pushback efficiencies due to a reliance on ground-handlers.
A number of factors can influence an airline’s turnaround processes and TATs, including the airline business model, onboard service, aircraft size, and the airports and routes being served.
Delta Air Lines says variables such as aircraft size, hub versus spoke airports, and international versus domestic routes all influence the length of a turnaround. Low-cost carriers (LCCs) and those operating mainly point-to-point networks are likely to have shorter average TATs than full-service airlines operating huband-spoke systems. Short TATs are a principal strategy of the low-cost business model and are designed to maximise aircraft utilisation. Full-service operators may have longer TATs, since their schedules are often designed around providing connections at a hub airport.
The turnaround process may therefore be governed more by schedule requirements, than by a desire to minimise TAT. Harrison points out that full-service airlines are more likely to need a heavier catering service than LCCs, which could add to their TATs.
A widebody’s extra capacity means that it will require a longer TAT than a narrowbody. For example, many of the standard turnaround processes, such as disembarkation and loading tasks, and servicing functions, like cleaning and catering, will take longer on a widebody,
while its longer range and fuel capacity mean that refuelling will also take longer. “Widebody ground times for fullservice carriers are often driven by commercial scheduling requirements, rather than the turnaround process,” says Harrison. “Widebodies operating longhaul sectors can be on the ground for six to eight hours, simply because of an airline’s preferred departure time. The growing number of low-cost, long-haul carriers may choose instead to minimise ground time and maximise utilisation.” Turnaround procedures and TAT can also be influenced by an airport’s infrastructure, operating procedures and how busy it is in terms of commercial aircraft movements and passengers. “Airport infrastructure and curfews can affect time on the ground,” says Michael Muzik, senior product manager of the weight and balance solution NetLine/Load, at Lufthansa Systems. “Turnarounds take longer at major hubs than at smaller regional airports, due to the higher complexity of hub airports. A typical LCC TAT might be 20-25 minutes at a provincial regional airport, but could take 40-45 minutes at a major hub.”
“Large airports operating near capacity might request standardised TATs from operators for gate allocation and planning purposes,” says Harrison. “At busy airports, TATs can be defined by slot availability.” easyJet says its TATs vary by airport according to the stand infrastructure.
“Our standard TAT for an A319 or A320 is 25 minutes when both the forward and aft doors can be used for disembarkation and loading,” says Philip Harbidge, operations performance manager at easyJet. “We use two doors when the parking stand allows passengers to walk
to and from the aircraft; be bussed to and from the aircraft; or when a jet bridge is used for the forward door, but steps can also be used for the aft door. On stands where only one door can be used, the standard TAT increases to 30 minutes. More time is also scheduled when an airport does not allow passengers to be on the aircraft while it is being refuelled.”
Certain route types can also influence turnaround times. There may be differences between domestic and international services, for example, related to different fuel, catering or baggage demands. “We adjust scheduled TATs according to the quantity of cabin baggage that is typically brought to the gate,” says Harbidge. “We allow more time for turnarounds on domestic Italian routes, for example, because this market tends to see high cabin bag numbers and few bags checked into the hold. A high number of cabin bags increases the time taken for boarding.”
Why efficiency matters
Ground-handling and turnaround operations can be responsible for flight delays, which result in additional costs for an airline. “An efficient turnaround is crucial to our operation because punctuality is important to our customers,” says Harbidge at easyJet. “It also allows us to maximise aircraft utilisation which keeps costs and fares low.”
Delta says that operational reliability is a key focus across the business and a smooth, safe turnaround is at the heart of that. It adds that many aircraft fly multiple sectors in a given day, so a delay could have a compounding effect on subsequent flights. Delta claims to have demonstrated a much improved flight completion factor and delay performance in recent years, and says this has helped to drive its strong revenue performance. “An efficient turnaround is very important for maintaining network schedules,” says Stephan Ellenberger, head of ground operations, Switzerland, at SWISS. “Flight delays are a serious challenge,” says Altay Fellah, vice
president, business development, Aviation Division at INFORM. “According to the US Bureau of Transportation (BTS), external factors such as severe weather conditions have been the main cause of late arrivals since it started collecting data in 2003, but weather delays are now
being surpassed by other factors. In more than 50% of cases, the leading reason for a delayed flight can now be traced to circumstances within the airline’s control, such as refuelling, cleaning, maintenance and crew scheduling. “From 2005 to 2015, 28-45 million delay minutes per year were attributed to factors that were under the direct control of US airlines,” continues Fellah. “This results in billions of dollars of delay costs. In 2016 the average cost of block time for US airlines was $62.55 per minute. A small setback in one of the turnaround processes can result in delays that are almost impossible to make up, if the problem is not identified, rectified, or at least limited early enough. The knock-on effect can lead to delays on other flights operated by the airline.” If an aircraft is scheduled to operate multiple sectors in a single day, but is delayed on one of its first flights, the remaining flight sectors could also be affected, and the extent of the delay could get worse throughout the day, if air traffic slots are missed. Delays to one aircraft can also affect other parts of an airline’s network, especially in a hub model where an aircraft may be forced to wait for large numbers of delayed connecting passengers. “If one aircraft is delayed on the stand, the next arriving flight may be unable to enter the gate at the allocated time,” says Jan Willem Kappes, business development manager at INFORM. “It
may also have to wait for ground service providers which have been delayed due to previous flights.” Airlines incur costs as a result of flight delays, including the provision of food and refreshments, hotel accommodation or alternative flights on other carriers for delayed passengers or those that have missed connections. Airlines may also be obliged to pay compensation to delayed passengers. European Union (EU) regulation EC 261/2004 dictates the levels of compensation that should be paid to delayed passengers travelling to or from an EU member state, depending on the extent of the delay. It is difficult to determine a global average for the delay-related costs incurred by airlines, due to the many potential variables and scenarios. “A number of studies have tried to identify the costs associated with delays, but the results have been varied,” says Harbidge. “Airlines also need to consider customer dissatisfaction levels when evaluating the impact of delays,” says Harrison. “Customer satisfaction is one element that can influence loyalty levels and the potential for repeat business.”
Technology solutions for improving efficiency
Some of the technology solutions available for improving efficiencies in ground operations, and reducing the potential for delays, are identified here: turnaround management software, which
is designed to optimise TATs; and E-Taxi solutions, which can increase efficiency in the period from off-blocks to take-off.
This summary is not intended as a comprehensive survey of suppliers, and other solutions may be available.
Turnaround management software
“Managing an aircraft turnaround is complex,” says Harrison. “There are many functions in the turnaround process, some of which may be carried out internally by the airline, while others are outsourced to third-party groundhandling or ramp-service agents. A large number of stakeholders are involved, such as pilots, cabin crew, customer service personnel, cleaners, security, agents and ramp personnel. Coordinating these functions and stakeholders is one of
the main challenges of a turnaround.” “Ideally, every turnaround needs proactive management and monitoring and I.T. solutions can be used to achieve this,” says Muzik. In a Lufthansa Systems white paper called ‘Airline Turnaround Management’, Muzik argues that many airlines are still not actively controlling their ground processes. He suggests that by implementing a turnaround management strategy, airlines could improve on-time performance and passenger satisfaction, and reduce delay costs. Muzik recommends setting up a reference model to plan and define the main turnaround processes and process points for measuring the performance of the turnaround. Some of the central turnaround processes are defined as: deboarding, de-loading, cleaning, catering, fuelling, boarding and loading. Each single turnaround process can be broken down into process points. For example, process points for disembarkation might include identifying the time when doors are opened and when the first and last passengers leave the aircraft. For fuelling they might include identifying when the refuelling truck arrives, when fuelling commences and when it is complete. Target times need to be defined for when each process point should begin, and dependencies between the different turnaround processes need to be identified. For instance, catering and cleaning can only start after de boarding has finished. It is recommended that target times be clearly allocated among stakeholders for each turnaround task. Muzik also suggests that airlines should apply rules to allow for differences between individual turnaround scenarios. This might include different TAT and process assumptions depending on the aircraft type, route and airport. “The key to coordinating a turnaround is to identify the critical path,” says Harrison. “This involves defining the desired processes and subtasks, when they should start and stop, and how long each stakeholder has to perform a task. Dependencies between tasks should also be identified, which means processes that cannot be started until another has been completed.” Muzik suggests airlines should establish service level agreements (SLAs) with third-party ground service providers, once turnaround processes, any related rules and target completion times have been defined. The SLA might include a requirement for service providers to complete turnaround tasks within a specific time frame. “Airlines should monitor the performance of their providers, but also implement an SLA which includes financial rewards or penalties depending on whether the service provider meets their agreed performance targets,” says Muzik. “Visible key performance indicators (KPIs) can be a useful tool for internal and third-party staff involved in the turnaround process,” says Harrison. “For third-party providers these may be based on SLAs.” There are software solutions on the market that help airlines and groundhandling companies coordinate the turnaround process and reduce the potential for ground-handling related delays. These solutions permit users to establish and measure bespoke turnaround processes, executed by thirdparty ground-handlers or airline personnel. They provide users with a realtime picture of turnaround status and the ability to compare this against set target times and SLAs. This can allow users to intervene proactively and reallocate resources where available, to try and prevent certain tasks falling behind schedule, which, in turn could lead to delays. An example of an intervention might be to request a quick cleaning from the relevant supplier. In addition to monitoring real-time operations, turnaround management software might also include tools for identifying longer terms trends in turnaround performance. “ICF has worked with airlines to help redesign their turnaround processes. This can also be part of a turnaround management software implementation project,” says Harrison.
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Original source: Aircraft Commerce