Regional contest

4.1.1 Establishing context

The influence of sampling - whether willingly applied or not - on static topological structures or in ATM performance metrics is here assessed. This study is conducted on various regions of the globe and while almost all regions considered (Australia, Brazil, Canada, India, Russia, China⁷ and the US⁸) are straightforward to define, it is slightly more complicated to delineate which countries does Europe refer to. Europe, in the sense of air transportation data, may refer to the geographical European Union (EU), but it might as well refer to the area managed by EUROCONTROL, which includes 44 participating countries of the European Civil Aviation Conference (ECAC). The European area defined within the Single European Sky (SES) project (launched in 2000 by the European Commission specifically to tackle the challenge of increasing delays) is in turn composed of the 28 EU members plus Norway and Switzerland. So, there are four different manners to define ‘Europe’, with the geographical definition being the ‘smallest’

one, forcing caution when referring to the ‘EU’ data. Turkey, for example, is in ECAC and a member EUROCONTROL, but not in the EU nor in SES. This situation leads to a certain fuzziness, as Turkey has been noted in 2014 to be the main contributor to ‘European’ (in EUROCONTROL sense) traffic growth, while, in contrast, remaining unaffected by the costs charging methods imposed within SES [Com15].

For the context of this PhD Thesis, ‘European’ data will designate the countries of the ECAC, being the area commonly used for ATM delay performance assessment, which is precisely the primary focus of our work. As it will be demonstrated in this chapter, user defined features like the number of airports or airlines (within a defined airspace area) significantly alter performance metric assessment.

7Air transport movement data for China often include Hong Kong, Macao and Taiwan but does not account for their airports.

8Air navigation services provided by the Contiguous United States (US CONUS’, i.e. the 48 states located on the North American continent). Alaska, Hawaii and Oceanic areas are excluded.

4.1.2 Market structure

Europe, Australia, Brazil, Canada, India, Russia and the US are all established free markets, with a variety of operator types and with a very limited state intervention in airline planning and operations. Recently, a significant growth in low-cost carriers (LCCs) [Com15] as been witnessed, while the other airlines adopted a merging/grouping strategy, with most of the largest companies now operating as airline groups. LCCs emergence into the market is exemplified in Tab. 4.2 by their presence within the top four airlines (ordered by volume of passengers carried) in both Europe and the US.

In this global context, China is an isolated case, as it is mainly a state-controlled system [CLZ15, CF12, ZR09]. Chinese airlines were merged into three large airline groups (Air China, China Eastern and China Southern) in 2002. Regional airlines - controlled and supported by government - emerged as supplementary carriers on approximatively a quarter of all routes (this having consequences on the hub development in China, as it will later be observed). This state-led system creates obvious disincentives to the emergences of LCCs, as larger airlines benefit from state welfare with some route and schedule advantages.

9International Airlines Group, formed by the merger of Iberia and British Airways.

Region Four largest carrier (groups) Alliances Carrier type Ownership Europe Lufthansa Group Star Alliance Mainline Private holdings

Ryanair No global alliance LCC

IAG⁹ oneworld Mainline

Air France-KLM SkyTeam Mainline

US American airlines oneworld Mainline Public companies

Delta Air lines SkyTeam Mainline

Southwest Airlines No global alliance LCC United Airlines Star Alliance Mainline

China Air China Star Alliance Mainline State shareholding

China Eastern SkyTeam Mainline State shareholding

China Southern SkyTeam Mainline State shareholding

Hainan Southern No global alliance Mainline Private holdings

Table 4.2: Carrier market structure by region. Reprinted with permission from [CBZ16].

In Tab. 4.2, we describe the extracted information about the market structure in the three biggest regions under study (Europe, US and China) from Flightglobal data¹⁰. As a side note, this market structure is currently evolving and changing, as we witness the dissipation of the demarcation between mainline companies and LCCs. Many examples of LCC emerging from mainline carriers (Vueling from IAG, Transavia from Air France-KLM, Eurowings from Lufthansa, Delta and United US groups also possess LCC ownership) can nowadays be found, blurring the line of the potential future market structure. In the case of China, the first three airlines do not have LCC ownership.

4.1.3 Flow management practices

The effect of sampling on Air traffic management (ATM) performance measurement will be assessed only for Europe and the US, being the two regions for which data containing delay related information have been obtained (OpenFlights data do not contain delay information, see Chapter 3). Therefore, this section will focus on describing the flow management practices of those two specific regions.

There is a fundamental difference between Europe and the US on their handling of the aircraft flow and delays. Europe adopts a more strategic approach, with planned routes and adaptive airport slots. Specifically, due to its political definition (see Section 4.1.1), Europe has to deeply resort to at-gate holdings because of the implemented ground delay program (GDP). Indeed, the fragmentation of the airspace in various service providers from different sovereign states -hence, the Single European Sky project - makes the versatile US management impossible to clone. In the US, the presence of a unique service provider (Federal Aviation Administration - FAA) allows for the redirection of airborne flights or even the re-routing of an entire flow of flights around a bad weather spot. Therefore, the GDP in the US is left as a last resort solution. On the opposite, Europe rarely uses en-route spacing, except for collision avoidance, and instead prefers to manage conflict through strategic tools (e.g. Calculated Take-Off Times - CTOTs - re-allocation) and speed control.

10https://www.flightglobal.com/. Accessed May 2016

Those differences have consequences on how airlines reports delays, as on-gate holdings can be originally caused by weather, congestion or any other kind of problems, but will be reported as Air Traffic Flow Management (ATFM) control cause; creating therefore differences between Europe and US delay analysis.