The Air Transport System

M Hirst

• Editore: Woodhead Publishing
• Anno: 2008
• ISBN:
  9781845695224
• Argomento: Technology & Engineering
• Categoria: Transportation & Navigation

Major operational elements of the world's air transport system are examined in this important book, which provides a rare overview and an invaluable single information source to managers in all sectors of the air transport industry.The air transport system considers route structure options in terms of operational impacts and describes the context and boundaries of the industry – the natural, regulatory and operational environments. 'Systems' perspectives are introduced to integrate the discussion of aircraft, airlines, airports and airspace issues. The issues faced in ensuring symbiosis of all these elements of the changing scene and the scope for developing balanced strategies to suit all stakeholder requirements are considered in depth to produce a comprehensive text with the potential to influence how well the air transport industry succeeds in meeting its many future challenges.

• Examines major operational elements of the world's air transport system
• Considers route structure options in terms of operational impacts
• Examines the natural, regulatory and operational boundaries of the industry

Part I

System objectives and environments

1

More than one answer?

Abstract

This chapter considers how civil aviation has changed the complexion of societies, and as a demand-led business it seems set to continue to grow. Because it is a controversial business this chapter focuses on turning towards holistic processes that can assist in finding enduring and acceptable solutions to operational dilemmas. A simple example is presented and solutions are considered that include a range of air service configurations. Extracted data are used to introduce properties of the air transport system that are explored in more detail throughout the book.

Key words

city pairs

influence of demand

frequency of service versus aircraft size

hub-and-spoke and direct route configurations

airport and airspace demands

1.1 Introduction: breadth of thinking

If flying was as easy as falling from a tree it would not have taken a million years or more for mankind to learn how to fly. The dream became a reality in the 20th century, and the progress from discovery to the stage it has reached, spanning barely 100 years, has surpassed the dreams of most of the individuals who have ever joined in the pursuit.

Civil aviation is only one branch of aviation, but it is an industry that is vigorous and a relatively young industry; it has changed the complexion of societies. All the indications are that it will continue to grow for the foreseeable future, because it is already popular where it is established and it is yearned for where there is still only limited access to its benefits. However, it is a business that has the attributes of a double-edged sword, able to blight as surely as it can enhance and encourage prosperity. While it is a business that will move ahead for many decades to come, its progress will be at times controversial.

A key reason for presenting an overall view of the air transport system is that it is already a victim of its own success. Alongside general approbation, it is an industry that also has to look inwards. As the volume of air traffic has grown, so the congestion in airspace and at airports has increased, and the quest for more and more capacity is a dilemma, because in such cases the benefits that air services bring are often viewed, even by the beneficiaries, as unjustifiable. The traditional route for finding solutions is to look towards technology, but a future based on such a single-discipline perspective looks bleak. Civil aviation is a complex system of many parts, and to develop as a whole, many stakeholders of its parts have found that turning towards holistic processes has assisted to find enduring and acceptable solutions to dilemmas. These pages consider how wide-ranging views can evolve from the traditional knowledge of the parts, and consider a process that will assist in the transition from the old to the new perspectives and that will be useful to people at all levels of involvement. It is largely to do with developing breadth of thinking and not in losing sight of anything that is already common knowledge.

The solutions that will evolve can be shaped by industry, as has often been the case in the past, or solely by the pressures that society applies, as is feared will be the case with internationally backed statutes promoting political correctness, or through a concerted effort by industry and society that will promote the way the demand is viewed and innovation is applied. The businesses that make up air transport have to balance their self-interests with these societal constraints if they are to maintain the degree of control they believe is rightly their own.

Inevitably, the customer will be asking for more. The definition of ‘more’ is far from simple, as they can crave more capacity or more service with prescribed qualities, or both, and more besides. Whether these are demands that require more on-board comfort, more agreeable flight times or more point-to-point travel depends largely on societal issues. This is well beyond the immediate scope of aviation per se, but at the same time these issues offer the opportunity to look for innovative solutions. Determining solutions will require thinking in terms of how demand is generated, served and satisfied, which goes a long way beyond the traditional ‘box’.

‘Out of the box’ thinking has become an established nomenclature for ‘systems engineers’ and much of what this new discipline has to offer is reflected in the approaches considered and advocated here. The important first principle to stress is that ‘systems engineering’ is not concerned with engineering in the physical sense. The word ‘engineer’ has roots in the Latin description of ingenuity, and the concepts that are used in ‘systems engineering’ are folded into these ideas, whereby those who create are encouraged to be innovative, or to apply ingenious thought processes, to find solutions that better serve broad needs. Systems engineers can be bankers, economists, philosophers and more, as well as engineers – and the best problem-solvers in society have always have been ‘out of the box’ thinkers.

In civil aviation the potential prize is worth the effort, because while many specialists have already learned to branch out from their own fields of interest, there is always a fear that treading even further afield is driven by ‘gut feel’ and has no justifiable reason. By adopting property-led perspectives, intuitive forays can become structured into objective and justifiable investigations. The outcomes from such curiosity trips become important contributors to opening new perspectives and encouraging the thought processes that are needed to craft solutions to ever more wide- ranging problems. The debate begins simply and grows rapidly into a multi- dimensional web of often contradictory issues, as will be illustrated very quickly in what follows.

1.2 A simple system

The demand for air services (indeed all transportation services) arises from population, its distribution and the economic and other factors that influence the propensity to travel within the population. These are properties of the natural environment. They are never static and they are often unpredictable.

Passengers interact directly with airlines, which offer them a service for the price of a ticket and vie with competitors to win the custom of individuals. Airlines monitor and judge where and when there will be sufficient demand to justify an air service, select aircraft types to serve the demand, create route structures and publish timetables. They use the airports that are available and can, in general, safely assume that the air traffic control (ATC) service providers that guide aircraft while they are airborne will be able to service their needs. This is a brief and generalised description of the route development process, and it is a fact that such important components as the airports and ATC services have little choice but to await the publication of demands that will be placed upon them. This is fine if these providers have the capacity to cope with the proposed level of demand.

However, capacity constraints are unavoidable and just occasionally airports and ATC systems reach their limits and fail the users. They do not fail in the dramatic sense – there is no desire to point at a danger signal. Quite simply, one day there is not the room for any more demand without unacceptable impact on the service, such as delay, as safety takes precedence over capacity. Rather than wait for that time to arrive, it is important that the businesses that make up civil aviation start to think innovatively now, not just about the problem but about the range of possible solutions. Some groups of individuals have started the process, indeed perhaps they all have, but some are more reluctant than others to enter the fray with their opinions. There should be no desire to oust the old and say ‘in with the new’. The aim must be to find out if debate based on wider perspectives offers the chance of finding new paradigms, and the hope has to be that such debate will generate the evidence to assure all interested parties that the industry would be hard pressed to serve communities better.

To add practical understanding to the situation and the complexity of the solutions, a very simple system that provides a starting point and is based on a very regularly shaped and homogeneous community will be analysed with regard to several possible ways of serving its travel requirements. It comprises nine identical locations, all equidistantly located, on a three-by- three grid.

The daily demand between city-pairs, based on their distance apart, will be assumed to be as shown in Fig. 1.1.

1.1 The assumed inherent demand for transport (passengers/day) between nine regularly spaced and similar-sized communities.

1.2.1 Service configuration 1

The first scenario to consider is that when a direct ‘point-to-point’ service is offered between all locations (Fig. 1.2). From any corner location (using A as an example), demand in passengers/day is:

1.2 Service configuration 1: direct services in a nine-airport system.

• demand to B = 300

• demand to C = 150

• demand to D = 300

• demand to E = 225

• demand to F = 125

• demand to G = 150

• demand to H = 125

• demand to I = 100 (and the total demand is 1475 passengers/day).

From any central-edge location (using B as an example), demand in passengers/day is:

• demand to A = 300

• demand to C = 300

• demand to D = 225

• demand to E = 300

• demand to F = 225

• demand to G = 125

• demand to H = 150

• demand to I = 125 (and the total demand is 1700 passengers/day).

From the centre, four locations generate a demand of 225 passengers/day and the other four generate a demand of 300, producing a total demand of 2100 passengers/day. Overall this develops a daily passenger demand of 14 800 passengers and involves 72 one-way services (this is treating A to B as additional to B to A). As might be expected, the busiest airport is at the centre.

If services are planned using a 50-seat aircraft and the desire is to fill 75% of seats in every flight (this can be referred to as a 75% passenger load factor), a number o...