I have been writing down a little bit of research on hubs in the last year. I wanted to set up a blog or something, but now I really just want to get it out there and discuss with you guys (its 2017 data and will get older and older), so here goes. Don't mistake me for a wannabe researcher or a journalist, it's all just for fun - so please be gentle with feedback. My biggest worry is that I do not have enough graphs - often I have to quote my lists and excel files. I hope to still manage to follow.Hubs – connecting one billion passengers a year
In most cases, flying means getting on an aircraft at your home airport and getting off the aircraft and leaving the airport at your destination. This is the case in around three quarters of all flights – because if there is sufficient demand and the right aircraft equipment to offer a direct flight between two airports, there will be at least one direct service. Of the four billion global passengers that boarded airplanes in 2017, three billion took a direct flight from origin to destination. But still the massive number of one billion had to change planes. This is where hubs come into play. They enable people to go from Tirana to Hong Kong or from Little Rock to Nagoya with only one stop. Only as soon as we have invented small one-person aircraft that can economically connect Tirana with Hong Kong or Little Rock with Nagoya will hubs become obsolete. This is my answer to a question I often get asked: why do we need hubs and why passengers that do not even want to go to – say – Amsterdam have to even further congest the airport’s infrastructure. Of course there are more profound approaches to answering this question, such as: only with connecting passenger can most of the long haul flights be filled in order to make them economically viable (with the aircraft technology we have today).
This leads to the very interesting phenomenon (or: paradox) that hubs incur – connecting passengers, that easily make up 70% of most long haul flights, are needed to fill planes at a certain contribution margin. Yet, in most cases it is origin or destination passengers who pay the fares that allow an airline to make a flight an economic success. But why do passengers that only take one flight (and thus cause much lower costs) pay more than passengers that take two flights? Well, you have it right there. Because the trip from A to B without the hassle of having to change planes is worth much more to a passenger, airlines can charge a premium for direct passengers. Thus the latter cross-subsidise the in many cases lower paying but in all cases more costly connecting passengers. This is why Air France will ‘steal’ passengers on Munich to New York from Lufthansa’s direct flights by offering lower prices just as Lufthansa will do the same on Paris – New York via Munich or Frankfurt (or Zurich, Vienna, Brussels or even Dusseldorf for that matter). Of course not only the added second flight involved is driving up costs – connecting passenger also add complexity to the flight processes, e.g. handling of luggage, rebooking or even hotel costs in the event of delays and missed flights.
Yet, the interesting field on costs and yields of hubs is not central to my article. Following aviation media and forums for centuries I feel there is a clear gap in the very basic descriptive statistics about hubs. It sounds almost too trivial, but my goal is to shed light upon a few very basic questions: what hubs are there in the world? What does very basic descriptive data tell us about their differences and commonalities? Do all American hubs work the same way or do all hubs of a similar size work the same way, be they in Asia or Africa? How can we cluster them into logical groups of hubs? And what does all of this tell us about the importance of geography of hubs or the strategy of airlines and alliances? A New Definition of Hubs
To even try to answer these questions, hubs need to be defined first. As a hobby aviation researcher (luckily with MIDT-Data at hand) I find it hard to take that even the big aviation data providers seem to define hubs as more or less large airports with connecting passengers (irrespective of airlines). Others calculate theoretical Connectivity Indices with potential connections based on flights and minimum connecting times over all airlines. The scientific literature does not solve this problem either – mostly lacking the adequate data on passenger flows and O&D city pairs. On forums like this one I feel the need to answer to every second topic with my data-set. I believe there is a clear gap in the public aviation knowledge for numbers about true hubs – not simply airports. Not hubs by some vague ‘large airport’-sytle definition, but by a very specific one, namely‘the operation of one airline with its (alliance and other code-share) partners at one airport’.
I believe that hubs need to be defined this way since hubs don’t simply happen (except maybe at exceptional mega-cities such as London or New York). They are planned in banks of arriving and departing flights by airlines and their partners. Every aviation geek would agree that Icelandair’s operation in KEF is one of the world’s truest hubs, even though by absolute passenger numbers the airport would not be dubbed a hub by many. On the other hand, Garuda Indonesia’s Jakarta operation is located at a very large airport (often dubbed a hub), but the airline’s operation does not qualify as a hub in 2017 (per my definition) since the share of connecting passengers was at only 9%.
For my humble research, I have defined that for an airline-partners-airport combination to be a hub, it needs to have
- at least one million connecting passengers per annum
and- at least a 10% share of connecting passengers
How did I come up with these numbers? First, the basis for every hub definition has to be connecting passengers simply because they make a hub a hub. Since this is no doctoral thesis, I took the liberty of trying around with definitions from my gut feeling of many years in the industry and the definition I chose roughly includes all the hubs I feel it should include and excludes those that I think it should. The line needs to be drawn somewhere, but not every airport can be a hub even though every airport has the odd connecting passenger. I found that only a combination of absolute and relative connecting passengers includes all the small and larger hubs that deserve to be called a hub. Defining a hub only by – say – 30% connecting passengers minimum would have penalised airline/airport operations in very large metropolitan areas – United’s Newark hub for example would have been ruled out. At the same time, defining hubs only by absolute connecting passengers – 2 million for example - would have punished small but intentional hubs such as [email protected]
or [email protected]
Sure there are borderline cases – it hurts to rule out the two Jakarta hubs of Garuda and Lion Air, both at only 9% connecting share but with 2.1 million and 1.8 million absolute connecting passengers. Also, Virgin Atlantic’s very interesting long-haul operation at Heathrow did not make it into my list – it only just misses the one million connecting passengers mark although its share lies at 24%. The line has to be drawn somewhere.This graph shows the world's Top 30 hubs (by my definition) by total daily connecting passengers, hubs by continents follow.Hubs in AfricaHubs in AsiaHubs in EuropeHubs in the GulfHubs by airlines in the big 3 alliances in North AmericaHubs by non-aligned airlines in North AmericaHubs in South America
Applying this definition to 2017 MIDT Data I have come up with a very interesting dataset that – as far as I am concerned – for the first time lists all 154 hubs there are in the world with passenger numbers (connecting passengers and O&D passengers) and connecting passenger share to start with. For my deeper analyses I have defined and calculated further KPIs such as- population of metropolitan areas that serve as catchment for the hubs
- avg. distance flown per passenger via each hub (city pair distance via hub)
- number of city pairs flown via each hub in different size and distance categories
- number of passengers on city pairs via each hub in different size categories and distance categories
- also, I have plotted waves of arriving and departing passengers for many hubs, indicating both the continents, to which flights go, and the height and width of waves.
Prior to clustering airline hubs in order to deeper analyse and compare them, I will introduce basic numbers and statistics about global connecting passenger flows. This should later help embed single hubs into the global aviation system.
Global (Connecting) Passenger Flows
Global Passenger Flows
Before we shift our focus towards hubs and connecting passenger flows, let’s look at the biggest overall passenger flows (including connecting traffic). Notably, the top global city pairs flown are all short domestic routes. Most of them are between the two dominant metro areas of a country, such as Beijing to Shanghai, Sydney to Melbourne, Rio de Janeiro to Sao Paolo, or Delhi to Mumbai. At a distant number one, however, is an odd one: flights between South Korean Capital Seoul (Gimpo and Incheon Airports) to the country’s main holiday island Jeju. An incredible 18,000 passengers take this trip per day each way. At number two and three, Japanese routes Tokyo to Sapporo and Fukuoka respectively follow. At only half the volume of the likes of Beijing to Shanghai, London to Dublin is the first European city pair at just over 5000 passengers per day each way. At the same time, it is only the second non-domestic city pair in the list just behind Tokyo - Seoul.
As for country pairs, China to China and USA to USA clearly top the global list at 15% and 14.3% of all passenger flows. Several domestic flows follow, such as India and Indonesia (both 3%), Japan (2.7%), Brazil (2.3%), as well as Australia, Turkey, and Russia (around 1.5% all). At number 20 of the list, the largest international passenger flow between two countries between the UK and Spain at 1.2% or roughly 60,000 passengers per day in each direction. (Connecting) Passenger Flows via Hubs
As for passenger flows with a connecting hub, let’s also look at city pair flows before we look at country pairs. The largest city-pair flow on the list with at least one stop – one could have guessed it – is the original ‘Kangaroo Route’ London to Sydney at 782 passengers per day each way. Although most one-stop flights in the world could be flown non-stop if economically viable, London-Sydney is one of the few relevant city pairs that actually require a stop for refueling. Now, as part of ‘Project Sunrise’, Qantas is looking at options to fly the route non-stop from the 2020s onwards on Boeing 787s, 777-8, or Airbus A350s. For a very long time, East Asian hubs Singapore, Bangkok, and Hong Kong have famously dominated this ‘Kangaroo’ flow. Today, at just over 200 passengers per day each way, Dubai is the top hub between the British Capital and Australia’s largest metro. Fellow gulf hubs Abu Dhabi (92) and Doha (51) are also forces to be reckoned, but Singapore (182) is still the clear runner-up. Hong Kong (81) and Bangkok (41) have fallen behind. To give you an idea of how hubs work: thick flows such as these are very rare. In my dataset there are over 85,000 city pairs with at least one passenger per day each way. Of these, not even 700 are 100 or more passengers thick. More than 110,000 have 10 or fewer passengers. And then there are thousands more flows with below one passenger per day that do not even show up in my data. Hubs cater for all these tiny traffic flows and this is what I wanted to stress when I mentioned earlier that hubs will exist until we invent little one-seater aircraft that can fly long haul missions.
Back to our list of global connecting passenger city pairs: before LON-SYD’s little sister Kangaroo-flow London – Melbourne shows up at number five on the list, three US coast to coast flows follow. Los Angeles and San Francisco to Washington D.C. are number two and three; Los Angeles to New York is number four. These American flows are notably all quite evenly split up between the at least ten hubs in the US with the likes of Denver, Chicago, Charlotte, Atlanta, or Phoenix leading most ranks. You can already see that the US is the country of hubs, a fact my analysis will clearly show.
Also in the top ten of global connecting passenger flows is New York to Israel’s main metro Tel Aviv. Aeroflot’s Moscow Sheremetyevo hub is the dominant player in connecting the city with the largest Jewish population in the world (New York at over one million) to the country with the largest Jewish population (Israel at 6.5 million). To give you a rough idea of how a flow like this one – a flow that can be and is flown directly – is distributed: roughly 1,500 total passengers fly between the two cities per day in each direction. 1,000 fly non-stop on the direct routes provided by El Al, United, and Delta. Around 500 choose to fly via a hub, mostly via Aeroflot’s hub at Moscow (117 passengers), other important hubs include [email protected]
(55), [email protected]
(47), and Air [email protected]
When we go on to look at country pair flows, the US leads by a mile (even though adding up the European countries would be a helpful measure to compare). Domestic US to US connecting traffic makes up an incredible 26% of global connecting traffic. Of these flows, Delta and American Airlines share more than a quarter each. Low-Cost Carrier Southwest is notably number three at 22% ahead of network carrier United at 17%. Back to country pairs: At a tiny 1.6% each, USA-Canada and USA-Mexico follow the mega US domestic connecting passenger market at number two and three. China to China (number four) and Brazil to Brazil (number five) have a mere 1%. Other important domestic connecting passenger markets are Indonesia, Russia, and Australia. The former is a growing country made up of hundreds of islands, thus making air travel necessary even at short distances; the other two are simply vast land masses. The thickest intercontinental connecting passenger flow between two countries is USA to India at 0.9% followed by USA to UK at 0.8%.
This is how the four billion global passengers were roughly split up between the flows they flew on in 2017. Shifting our focus towards hubs, we have seen on what city and country pairs the one billion connecting passengers traveled. But before I will go deeper into analysing single hubs and hub groups, they need to be clustered. This is what I will do in the next chapter.Clustering Airline Hubs
The 154 global hubs of 2017 are as different as they are fascinating. Some are very small and cater for only a few very thick city pairs: Eva Air’s operation at Taipei takes more than 150 people from Ho Chi Minh City to Los Angeles every day. Yet, there are much bigger hubs such as Lufhansa’s Munich operation where the largest city pair is Rome to Hamburg at a mere 23 daily passengers. A hub with a deep network like [email protected]
, however, has tens of thousands of city pairs with less than one passenger per day, while Eva [email protected]
only has a fraction of this number. Some hubs connect their average passengers with a combination of two flights under 1000km – American Airlines does so at its Washington Reagan (DCA) hub, and so does LATAM at Sao Paolo’s secondary Congonhas Airport (CGH). Others, such as Singapore Airlines, famously connect Europe to Australia and other long haul flows at an average of over 9000km flown per passenger. Then there are hubs at the same global location that work completely differently. Dubai – the second largest hub in the world – connects all continents with a mega-fleet of wide-bodied aircraft. Nearby Gulf Air at Bahrain Airport specialises in connecting the Gulf and Middle East to India on A320s. Then there is the hub that eclipses every other hub with its sheer numbers: Delta’s Atlanta operation that makes Hartsfield-Jackson Int’l Airport, with six parallel runways, the world’s largest in terms of passengers.
First, in order to cluster global airline hubs (by my definition) I have plotted them on two axes (see graph below). The X-Axis contains total connecting passengers per day of the airline/airport operation; the Y-Axis indicates the percentage of connecting passengers vs. Origin & Destination (O&D) passengers of the same operation. Note that throughout my analyses I count connecting passengers twice – once on the inbound flight and once on the outbound flight they connected to – in order to stay in line with the general approach to airport and airline statistics.All 154 hubs plotted, airport codes follow
The results show the majority of airline hubs scattered in a curve (‘hub-curve’) from the bottom left where there are many hubs in one place up to the top right hand corner where the density of hubs becomes very thin. On the bottom left are hubs where only a few thousand total daily connecting passengers represent merely a 10% share of an airline’s passengers at an airport. These only just classify as hubs in my definition. In the top right hand corner are hubs that combine a large number of absolute connecting passengers with a high proportion of total passengers at the airline’s operation at this airport. Additionally there are a few hubs that leave the curve – some to the top left corner and some to the bottom/right or top/left hand sides of the curve. Notably there are no hubs in the bottom right corner – for this would mean that there are hubs of several hundreds of millions of passengers. Today, Delta Airlines and its (SkyTeam-) partners’ Atlanta hub is the largest hub with around 80 million passengers, coincidently at the world’s largest airport with more than 100 million passengers in total.The hub-curve
Clustering these hubs into groups for the first time, lacking professional clustering software, I have chosen a hands-on approach simply using proximity on the plot of connecting passengers and their share at a hub. Later, I added data about City population and average flown distances via hubs to help sharpen the clusters. All 154 hubs clustered into groups‘Regular’ hubs on the ‘hub-curve’: Small Hubs to Super Hubs
First, however, I have defined five clusters of hubs that roughly make up the ‘hub-curve’ I have mentioned above. These groups become smaller as hubs get bigger from bottom left to top right. Clusters range from the largest group of the ‘Small Hubs” in the bottom left corner to the two ‘Super Hubs’ of Emirates and Delta Airlines at Dubai and Atlanta respectively. Don't worry, I will go through the groups on by one, starting with the largest hubs.‘Super Hubs’
- 70% - 75% connecting passengers share
- over 100,000 daily connecting passengers
- [email protected] (ATL)
- [email protected] (DXB)
First: those two ‘Super Hubs’ are massive; especially Atlanta could have easily deserved a category on its own. However, a comparison is very interesting. 80,000 actual people (counted one at landing and once at take-off to get to 160k passengers) change planes at ATL on Delta every day, nearly 60,000 at Dubai on Emirates. Yet, the two hubs could not be more different in the way they work (see image below), even though they are both located in similarly large metros (between four and six million inhabitants). Delta’s Atlanta Skyteam hub has an average weighted passenger-distance of only 2,879km (note that all global hubs have an average of around 5,000km). Around 90% of connecting passengers are domestic, a further 6% Caribbean and Central American. In stark contrast, Emirates’ Dubai hub averages nearly fourfold the distance at 10,242km with its wide-body only fleet of Airbus A380s and Boeing 777-300ERs. Only 12% of connecting passengers use [email protected]
for regional flying between cities of the Gulf and the Middle East while nearly two-thirds alone (65%) use it on the global North-West to South-East-Corridor between Europe, Southeast Asia, the Indian Sub-Continent, and Australia. Dubai – along with the other Gulf-based hubs and Istanbul – is perfectly located to cater for these traffic flows. As a country-pair, however, USA to India is [email protected]
’s strongest (5.4%) and India is its source of the highest number of connecting passengers (9.3%) followed by the UK (8.6%). The strongest city-pairs via [email protected]
are routes from Muslim mega-cities Karachi (25 million) and Jakarta (29 million) to Jeddah – gateway to the place of Muslim pilgrimage town Mecca. These are some of the thickest one-stop city pair flows there are in the world at around 150 connecting passengers per day each way.The world's two absolutely dominant hubs could not work more differently: Emirates' Dubai hub (above) and Delta's Atlanta hub (below) shown here by their waves of arriving and departing flights on a random day in 2017. Destinations are coloured in by continents (Western Europe being blue, Eastern Europe light blue, North America red, Central America pink, South America purple, Asia yellow, Australia green, Africa grey, Middle East brown). Not only is it obvious that [email protected] is very domestic and [email protected] very intercontinental (check out the waves of pax going from blue (Europe) to green/yellow (Asia/Pacific!!)), also the peaks are more than twice the height at ATL - Delta using much smaller aircraft to many more destinations. Also, [email protected] has much fewer and longer peaks with only three connecting waves per day in which (mostly long haul) passengers have longer connecting times as compared to [email protected] The graph for the Emirates hub also makes the point that the hub could not exist if it wasn't for the 24h operations at the airport.‘Very Large Hubs’
- 55% - 75% connecting passengers share
- 70,000 - 100,000 daily connecting passengers
- [email protected] (CLT)
- [email protected] (DFW)
- [email protected] (AMS)
- [email protected] (FRA)
- [email protected] (IST) The 'Very Large Hubs' by size of connecting passengers and coloured in by alliance
Moving down the ‘hub-curve’ come the five ‘Very Large Hubs’. They consist of two US-hubs – notably two American Airlines oneworld hubs, Dallas Fort-Worth and Charlotte – and three European hubs, Frankfurt (Lufthansa), Amsterdam (KLM), and Istanbul (Turkish Airlines). Similar to [email protected]
, both American Airlines hubs are located in the southern states of the USA and they, too, are very regional hubs. [email protected]
has a share of 96% of connecting passengers to and from North and Central America as well as the Caribbean (at 3639km average weighted passenger-distance). At 99%, [email protected]
(2,313km) is even less connected to the world, only a mere 1% of passengers connect to Europe.
The European hubs, on the other hand, all average around 6,000km distance per passenger, even though Turkish Airlines’ hub at Istanbul works very differently than the other two. [email protected]
and [email protected]
feature a similar set of passenger flows with Europe equally important at 67% of connecting passengers (AMS focuses more on Western Europe, especially the UK, while FRA has a larger share of Eastern Europe-bound passengers). North America (around 14% for both) and Far East Asia (around 6% for both) follow, while Amsterdam then has a larger focus on ex-colonies in Africa, South America, and the Caribbean. Frankfurt specializes more in connecting traffic to the Middle East and India. Notably, the domestic share of connecting passengers of Turkish’s IST hub at 11% is smaller than the UK’s share of passengers at KLM’s AMS hub (12%). Frankfurt, in comparison, has 16% domestic connecting passengers.
Turkish Airlines’ main hub at Istanbul Ataturk (IST) has a very broad connecting traffic pattern. While Europe is its most important market, at (46%) it is not as important as it is to the competition in this cluster. Its traffic flows are much more evenly split with shares of passengers to and from North America, Gulf, India Sub-Continent, Southeast Asia, and Africa all making up between 4 and 8 percent. Making efficient use of its geographic location, [email protected]
uses narrow-body equipment on many more medium-haul route than its competition and thus serves more destinations in all parts of Africa, the Middle East, and Central Asia than any other hub. An analysis of the distribution of connecting passengers over different total flight distances via the hubs underlines this observation: While [email protected]
’s and [email protected]
’s curves peak at passengers flying intra-European 1,000-2,000km and vanish to almost nothing for city pairs between 3,000 and 6,000km, [email protected]
peaks between 2,000 and 5,000km. On the long-haul end of the scale, all three hubs interestingly peak at the same category of 9,000-10,000km. AMS and IST show a nearly parallel height pattern between 8000km and 12000km while Frankfurt – with its strong focus on North America and Far East Asia – carries almost double the amount of connecting passengers between 8,000 and 10,000km.[email protected] (above) has five clear hub waves while [email protected] (below) has four that are much less visible. Note that Turkey is listed as being Eastern European in my dataset, that is part of why [email protected] is dominated by light blue colours. The Turkish hub resembles [email protected] much more than it does its continental European competitors. This of course has to do with the airport being open 24h like DXB, unlike the likes of FRA or AMS.Look at [email protected]! This is the same scale as FRA and IST above! Isn't it fascinating how hubs run so differently can cater for a very similar amount (and precentage) of connecting passengers? American's largest hub (yes, more connecting passengers than Dallas!) has strong similarities to next door neighbour [email protected], albeit being even more clear cut between banks of arrivals and departures. In all my research I have not seen anything as clinical as [email protected]‘Large Hubs’- 50% - 60% connecting passengers share
- 25,000 - 50,000 daily connecting passengers
- [email protected] (PHX)
- [email protected] (DTW)
- [email protected]/St. Paul (MSP)
- [email protected] (ORD)
- [email protected] (IAH)
- [email protected] (DEN)
- [email protected] (FCO)
- [email protected] (MUC)
To the bottom left of the ‘Very Large Hubs’ lies a group of eight ‘Large hubs’. Apart from Chicago, which is on the overlap to the ‘Large Mega City Hubs’, the group of hubs has a homogenous set of metropolitan areas in which they are located. Starting with Munich at two million inhabitants, the group averages around four million with Houston, home of United’s hub at Bush International Airport, the largest at six million. The Windy City, with a metro of 9.2 million Chicagoans almost a mega city, finds itself in this group and not in the group’s ‘Mega City Hubs’ sister group, since its profile of average connecting passenger distance at 3,650km is very similar to that of the other regular ‘Large Hubs’. The eight ‘Large Hubs’ are a very homogenous group with around 3,500km on average and all in between 3,000 and 4,000km. The ‘Large Mega City Hubs’, in comparison, average at more than double, around 7,500km distance flown per connecting passenger.
A look at their location explains the similarities between the members of the ‘Large Hubs’. Not only are the metro areas of similar size, they are also all located within the continent. I thought about naming this group ‘Large Continental hubs’. In contrast, the majority of mega cities and their hubs lie on the edge of continents at the great oceans, which in part explains their connecting traffic patterns (see ‘Mega City Hubs’). Of the six (!) US-hubs in this small group of ‘Large Hubs’, half are Mid-Western hubs ([email protected]
, [email protected]
/St. Paul, and [email protected]
). Houston lies on the coast of the Mexican Gulf but can be dubbed ‘continental’ with regard to the large oceans and continents. Phoenix is the closest to an Ocean within the group, but still has the entire 40 million-state of California between itself and the Pacific. Interestingly, over in Europe, Munich (Lufthansa) lies as cozily within the European continent as Denver (United) does in North America. Applying the same oceans and continents logic to Rome (Alitalia), the Italian capital can also be called continental. Rome’s southern central location within Europe makes it a natural gateway for (North-) Europeans towards Africa (in theory), yet the African markets are almost negligible compared to the major Asian and American markets.
The distance per passengers patterns of the ‘Large Hubs’ represent the continental nature of their locations. All eight hubs have their by far largest peak at 1,000-4,000km, with the two European hubs peaking earliest at 1,000-2,000km, notably on par with Detroit. The other five US-American hubs – due to further distances in the much larger continent – peak later, between 2,000 and 4,000km. Munich is very Europe-centric at 82% of total connecting passengers, much more than big-sister hub FRA (see above). Fittingly dubbed ‘northern-most Italian city’, MUC is even more reliant on traffic from Italy (12%) than [email protected]
is famously on traffic from the UK (see above). [email protected]
also has a very strong Eastern European presence with Romania and Poland at a larger share than European heavy-weights France and the UK (!). Italy’s major hub, [email protected]
- coincidently a competitor within the same hub-cluster, suffers from Munich taking much of the wealthy North-Italian traffic on its North-bound journeys to the US and Asia. The FCO hub has, being centrally located within Italy, found its niche in serving traffic between Southern and Northern Italy and its islands. A (by European standards) staggering 21% of connecting traffic stays within the country, a number matched only by four hubs in Europe that we will see in later clusters. I find these numbers so fascinating, so let me quickly take you through them on a short excursion on domestic hubs: First, at 22% domestic share, the largest hub in Europe’s largest country: Aeroflot’s Moscow (SVO) hub that today still follows its historic role in connecting the enormous Russian landmass. Aeroflot was, in 1991, the world’s largest airline and three times larger than the biggest airlines of the Western world. Secondly, Air France’s secondary hub at Paris Orly (ORY) at 22% sports the same amount of domestic to domestic flying. However, when adding in the French ‘départements et régions d’outre-mer’ (most importantly La Réunion, Martinique, Guadeloupe, and French Guiana), Air [email protected] becomes a 75% France to France hub. Then there are the two Scandinavian hubs of [email protected] (23% Norway to Norway connecting traffic) and [email protected] (21% Sweden to Sweden connecting traffic) that often serve as an alternative to motorways or trains by connecting very small airports in very challenging geographic (and often weather) conditions. More on the latter three hubs can be found in the chapter on ‘Small Hubs’.
Back to our ‘Large hubs’: On the long-haul side of the distance per passengers curves, only [email protected]
and to a lesser extend [email protected]
have noteworthy peaks. Munich has nearly 50% more volume but both peak at the typical 7,000-8,000km distance for Europe-US-East Coast/Mid-West traffic, while Munich also has a strong point at 9,000-10,000km where Europe-West Coast and Europe-Far East-Asia traffics lie. The rest of the cluster has small long haul peaks with Delta’s Asian focus at Detroit (see image below) being one observation at 11,000 km to 12,000 km flown.[email protected], [email protected], and [email protected]: three of the 'Large Hubs' and their waves. Denver is clinical, similar to Charlotte, Munich has six broader waves. Delta's Motor City hub has - compared to all red hubs like Denver or Charlotte - a few yellow spots here and there. These represent its focus on Asian destinations.
Ok guys, this is it for now. I will continue with the medium sized and the small hubs the coming week. Then I will go on to the special hubs like the Mega City hubs, the Pure Connectors and the Niche Hubs - granted you guys want to read more of my stuff on boring old hubs
Best regards for now!