Investigations into ways to reduce flight delays at airports have concluded that reducing variability in departure and arrival times is central to improving punctuality.
Eleven major European airports participated in a study to determine the drivers behind air transport punctuality, a probe Eurocontrol describes as the first attempt to find specific links between airport, airline and air traffic-management performance.
The airports involved in the study, supported by Eurocontrol Central Office for Delay Analysis and Central Flow Management Unit (CFMU) data, were responsible for the highest flow-management delays in 2003: Amsterdam Schiphol, Barcelona, Frankfurt, London Heathrow, Madrid, Milan Malpensa, Munich, Paris Charles de Gaulle, Rome Fiumicino, Vienna and Zurich.
“Beyond measuring punctuality and understanding delay causes, the variability of flight operations emerged as an important issue towards improving air transport performance,” says the study by Eurocontrol’s performance review commission.
Variability is the statistical spread of aircraft departure or arrival times; the greater the spread, the more unpredictable the flight operations. “Tightening the distribution of arrival times allows time buffers in block times to be reduced while maintaining punctuality,” the study says.
Compressing half of European scheduled flights by 5min, says the commission, would generate savings of around €1 billion ($1.2 billion) a year. “A reduction of variability directly translates into improved punctuality or reduced costs to meet the same punctuality target,” it adds.
The study makes eight proposals for action – four addressing overall network issues and four aimed at local airport community issues:
- improve understanding of network effects because, despite a large proportion of reactionary delays – the knock-on effects from earlier hold-ups – there is only limited knowledge about how individual airline and airport strategies affect the network as a whole;
- Eurocontrol’s CFMU should consider post-event analysis for air traffic flow-management performance, perhaps formally recording actual demand when flow-management regulations are issued to assess decision-making quality;
- look at modifying flow-management priority rules – perhaps by giving preference to on-schedule flights – to see whether this could cut reactionary delays;
- consider the benefits of en-route sequencing to generate more continuous and accurate delivery of arrival streams improve flight efficiency within terminal airspace;
- explore the scope for improving airport capacity-declaration processes, with a view to using strategies such as de-peaking or using slot information more effectively;
- extend the use of collaborative decision-making, applying it to the arrival, turnaround and departure phases of flight;
- strive to maintain declared peak arrival capacity, and eliminate the differences in procedures applied between different airports, during poor weather conditions;
- fine-tune the arrival flow into airports by combining and balancing techniques such as flow-management regulations – which are relatively coarse and inaccurate – with tactical en-route sequencing, de-peaking, and the use of local vectoring or holding.
While punctuality – defined as the proportion of flights meeting scheduled departure and arrival times to within 15mins – is a generally-accepted operational performance indicator for airlines and airports, Eurocontrol says: “Punctuality is a valid indicator from a passenger viewpoint. However, punctuality alone is not, of itself, a sufficient indicator to assess individual airport or air traffic control performance.
“Early arrivals have also been examined as this can be a problem as well for air transport operations.”
Eurocontrol warned earlier this year that airport congestion is threatening to become the primary cause of delays and that by 2025 the top 20 European airports could be saturated for much of the day.
Source: Flight International
