Airline hub: Difference between revisions

Content deleted Content added

Inline

Latest revision as of 22:37, 3 November 2024

An airline hub or hub airport is an airport used by one or more airlines to concentrate passenger traffic and flight operations. Hubs serve as transfer (or stop-over) points to help get passengers to their final destination.^[a]^[b] It is part of the hub-and-spoke system. An airline may operate flights from several non-hub (spoke) cities to the hub airport, and passengers traveling between spoke cities connect through the hub. This paradigm creates economies of scale that allow an airline to serve (via an intermediate connection) city-pairs that could otherwise not be economically served on a non-stop basis. This system contrasts with the point-to-point model, in which there are no hubs and nonstop flights are instead offered between spoke cities. Hub airports also serve origin and destination (O&D) traffic.

Operations

The hub-and-spoke system allows an airline to serve fewer routes, so fewer aircraft are needed.^[3] The system also increases passenger loads; a flight from a hub to a spoke carries not just passengers originating at the hub, but also passengers originating at multiple spoke cities.^[4] However, the system is costly. Additional employees and facilities are needed to cater to connecting passengers. To serve spoke cities of varying populations and demand, an airline requires several aircraft types, and specific training and equipment are necessary for each type.^[3] In addition, airlines may experience capacity constraints as they expand at their hub airports.^[4]^[5]

For the passenger, the hub-and-spoke system offers one-stop air service to a wide array of destinations.^[3]^[6] However, it requires having to regularly make connections en route to their final destination, which increases travel time.^[6] Additionally, airlines can come to monopolise their hubs (fortress hubs), allowing them to freely increase fares as passengers have no alternative.^[4] High domestic connectivity in the United States is achieved through airport location and hub dominance. The top 10 megahubs in the US are dominated by American Airlines, Delta Air Lines and United Airlines, the three largest United States–based airlines.^[7]

Banking

Airlines may operate banks of flights at their hubs, in which several flights arrive and depart within short periods of time. The banks may be known as "peaks" of activity at the hubs and the non-banks as "valleys". Banking allows for short connection times for passengers.^[8] However, an airline must assemble many resources to cater to the influx of flights during a bank, and having several aircraft on the ground at the same time can lead to congestion and delays.^[9] In addition, banking could result in inefficient aircraft utilisation, with aircraft waiting at spoke cities for the next bank.^[9]^[10]

Instead, some airlines have debanked their hubs, introducing a "rolling hub" in which flight arrivals and departures are spread throughout the day. This phenomenon is also known as "depeaking".^[10] While costs may decrease, connection times are longer at a rolling hub.^[9] American Airlines was the first to depeak its hubs,^[9] trying to improve profitability following the September 11 attacks.^[8] It rebanked its hubs in 2015, however, feeling the gain in connecting passengers would outweigh the rise in costs.^[8]

For example, the hub of Qatar Airways in Doha Airport has 471 daily movements to 140 destinations by March 2020 with an average of 262 seats per movement; in three main waves: 05:00–09:00 (132 movements), 16:00–21:00 (128) and 23:00–03:00 (132), allowing around 30 million connecting passengers in 2019.^[11]

History

United States

Before the US airline industry was deregulated in 1978, most airlines operated under the point-to-point system (with a notable exception being Pan Am).^[4] The Civil Aeronautics Board dictated which routes an airline could fly. At the same time, however, some airlines began to experiment with the hub-and-spoke system. Delta Air Lines was the first to implement such a system, providing service to remote spoke cities from its Atlanta hub.^[6] After deregulation, many airlines quickly established hub-and-spoke route networks of their own.^[3]

US majors top 20 airports, millions of departing passengers, 2022^[12]^[13]
Airport	Region ^{[citation needed]}	2022 pax.	AA	DL	UA	WN
Atlanta	South	45.37		33.87		3.68
Dallas/Fort Worth	South	35.33	24.34
Denver	West	33.75			12.34	10.43
Chicago–O'Hare	Midwest	33.13	7.71		11.13
Los Angeles	West	32.29	4.91	5.42	4.74	3.21
New York–JFK	Northeast	26.99	3.37	6.23
Las Vegas	West	25.26				8.87
Orlando	South	24.44				4.79
Miami	South	23.68	13.93
Charlotte	South	23.09	16.14
Seattle/Tacoma^[c]	West	22.11		4.47
Phoenix–Sky Harbor	West	21.79	7.39			7.62
Newark	Northeast	21.66			12.15
San Francisco	West	20.40			8.50
Houston–Intercontinental	South	19.80			11.08
Boston	Northeast	15.42		3.26
Fort Lauderdale	South	15.36
Minneapolis/St. Paul	Midwest	15.20		8.52
New York–LaGuardia	Northeast	14.36	2.49	2.92
Detroit	Midwest	13.73		7.95

Middle East

In 1974, the governments of Bahrain, Oman, Qatar and the United Arab Emirates took control of Gulf Air from the British Overseas Airways Corporation (BOAC). Gulf Air became the flag carrier of the four Middle Eastern nations. It linked Oman, Qatar and the UAE to its Bahrain hub, from which it offered flights to destinations throughout Europe and Asia. In the UAE, Gulf Air focused on Abu Dhabi rather than Dubai, contrary to the aspirations of UAE Prime Minister Mohammed bin Rashid Al Maktoum to transform the latter into a world-class metropolis. Sheikh Mohammed proceeded to establish a new airline based in Dubai, Emirates, which launched operations in 1985.^[15]

Elsewhere in the Middle East region, Qatar and Oman decided to create their own airlines as well. Qatar Airways and Oman Air were both founded in 1993, with hubs at Doha and Muscat respectively. As the new airlines grew, their home nations relied less on Gulf Air to provide air service. Qatar withdrew its share in Gulf Air in 2002. In 2003, the UAE formed another national airline, Etihad Airways, which is based in Abu Dhabi. The country exited Gulf Air in 2006, and Oman followed in 2007.^[15] Gulf Air therefore became fully owned by the government of Bahrain.

Emirates, Qatar Airways, Saudia and Etihad Airways have since established large hubs at their respective home airports. The hubs, which benefit from their proximity to large population centres,^[15] have become popular stopover points on trips between Europe and Asia, for example.^[16] Their rapid growth has impacted the development of traditional hubs, such as London-Heathrow, Paris-Charles de Gaulle, and New York-JFK.^[17]

Types of hubs

Cargo hubs and scissor hubs

A cargo hub is an airport that primarily is operated by a cargo airline that uses the hub-and-spoke system. In the United States, two of the largest cargo hub airports, FedEx's Memphis Superhub and UPS Louisville Worldport, are close to the mean center of the United States population. FedEx's airline, FedEx Express, established its Memphis hub in 1973, prior to the deregulation of the air cargo industry in the United States. The system has created an efficient delivery system for the airline.^[18] UPS Airlines has followed a similar pattern in Louisville. In Europe, ASL Airlines, Cargolux and DHL Aviation follow a similar strategy and operate their primary hubs at Liège, Luxembourg and Leipzig respectively.^[19]

Additionally, Ted Stevens International Airport in Anchorage, Alaska, is a frequent stop-over hub for many cargo airlines flying between Asia and North America. Most cargo airlines only stop in Anchorage for refueling and customs, but FedEx and UPS frequently use Anchorage to sort trans-pacific packages between regional hubs on each continent in addition to refueling and customs.^[20]

Passenger airlines that operate in a similar manner to the FedEx and UPS hubs are often regarded as scissor hubs, as many flights to one destination all land and deplane passengers simultaneously and, after a passenger transit period, repeat a similar process for departure to the final destination of each plane.^[21] In past, Air India operated a scissor hub at London's Heathrow Airport, where passengers from Delhi, Ahmedabad, and Mumbai could continue onto a flight to Newark.^[22] Until its grounding, Jet Airways operated a similar scissor hub at Amsterdam Airport Schiphol to transport passengers from Bangalore, Mumbai and Delhi to Toronto-Pearson and vice versa. At the peak of operations at their former scissor hub at Brussels prior to the 2016 shift to Schiphol, flights operated from Mumbai, Delhi, and Chennai and continued onward to Toronto, New York, and Newark after a near-simultaneous stopover in Brussels and vice versa.^[23] An international scissor hub could be used for third and fourth freedom flights or it could be used for fifth freedom flights, for which a precursor is a bilateral treaty between two country pairs.

WestJet used to utilize St. John's as a scissor hub during its summer schedule for flights inbound from Ottawa, Toronto, and Orlando and outbound to Dublin and London–Gatwick. Qantas similarly used to utilize Los Angeles International Airport as a scissor hub for flights inbound from Melbourne, Brisbane or Sydney, where passengers could connect onwards if traveling to New York–JFK.

Focus city

In the airline industry, a focus city is a destination from which an airline operates limited point-to-point routes.^[25] A focus city primarily caters to the local market rather than to connecting passengers.^[26]^[27]

Although the term focus city is used to mainly refer to an airport from which an airline operates limited point-to-point routes, its usage has loosely expanded to refer to a small-scale hub as well.^[28] For example, even though JetBlue's operations at New York–JFK resemble that of a hub, the airline still refers to it as a focus city.^[9]

Fortress hub

A fortress hub exists when an airline controls a significant majority of the market at one of its hubs. Competition is particularly difficult at fortress hubs.^[29] As of 2012^[update], examples included Delta Air Lines at Atlanta, Detroit, Minneapolis/St. Paul and Salt Lake City; American Airlines at Charlotte, Dallas Fort Worth, Miami, and Philadelphia; and United Airlines at Houston–Intercontinental, Newark and Washington-Dulles.^[30]

Flag carriers have historically enjoyed similar dominance at the main international airport of their countries and some still do. Examples include Aeromexico in Mexico City, Air Canada in Toronto–Pearson, Air France in Paris–Charles de Gaulle, British Airways in London–Heathrow, Cathay Pacific in Hong Kong, Copa Airlines in Panama City, Emirates in Dubai, Ethiopian Airlines in Addis Ababa, Finnair in Helsinki, Iberia in Madrid, Japan Airlines in Tokyo-Haneda, Iran Air in Imam Khomeini, ITA Airways in Rome, Aeroflot in Moscow–Sheremetyevo, Korean Air at Seoul–Incheon, KLM in Amsterdam, Lufthansa in Frankfurt, Qantas in Sydney, Qatar Airways in Doha, Singapore Airlines in Singapore, South African Airways in Johannesburg, Swiss International Air Lines in Zurich, TAP Air Portugal in Lisbon, Turkish Airlines in Istanbul, and Aegean Airlines in Athens.

Primary and secondary hubs

A primary hub is the main hub for an airline. However, as an airline expands operations at its primary hub to the point that it experiences capacity limitations, it may elect to open secondary hubs. Examples of such hubs are Air Canada's hubs at Montréal–Trudeau and Vancouver, British Airways' hub at London–Gatwick, Air India's hub at Mumbai and Lufthansa's hub at Munich. By operating multiple hubs, airlines can expand their geographic reach.^[31] They can also better serve spoke–spoke markets, providing more itineraries with connections at different hubs.^[1]

Cargo airlines like FedEx Express and UPS Airlines also operate secondary hubs to an extent, but these are primarily used to serve regional high-demand destinations because shipping packages through its main hub would waste fuel; an example of this would be FedEx transiting a package through Oakland International Airport when shipping packages between destinations near Seattle and Phoenix, Arizona instead of sending deliveries through the Memphis Superhub.^[20]

Reliever hub

A given hub's capacity may become exhausted or capacity shortages may occur during peak periods of the day, at which point airlines may be compelled to shift traffic to a reliever hub. A reliever hub has the potential to serve several functions for an airline: it can bypass the congested hub, it can absorb excess demand for flights that could otherwise not be scheduled at the congested hub, and it can schedule new O&D city pairs for connecting traffic.

One of the most recognized examples of this model is Delta Air Lines' and American Airlines' uses of LaGuardia Airport as a domestic hub in New York City, due to capacity and slot restrictions at their hubs at John F. Kennedy International Airport. Many regional flights operate out of LaGuardia, while most international and long-haul domestic flights remain at JFK.

Lufthansa operates a similar model of business with its hubs at Frankfurt Airport and Munich Airport. Generally speaking, a marginal majority of the airline's long-haul flights are based out of Frankfurt, while a similarly sized but smaller minority are based out of Munich.

Moonlight hub

In past history, carriers have maintained niche, time-of-day operations at hubs. The most notable was America West's use of McCarran International Airport (now named after longtime Nevada Senator Harry Reid) in Las Vegas as a primary night-flight hub to increase aircraft utilization rates far beyond those of competing carriers.

Notes

^ Colloquially, an airline hub may be defined as an airport that receives many passengers or as an airport that serves as the operating base of an airline, whether or not the airline allows for connecting traffic.^[1]
^ The Federal Aviation Administration of the United States defines a hub in terms of passenger enplanements. Specifically, a hub is an airport that handles 0.05% or more of the nation's annual passenger boardings.^[1]^[2]
^ Alaska Airlines: 11.4^[14]

References

^ ^a ^b ^c Holloway, Stephen (2008). Straight and Level: Practical Airline Economics (3rd ed.). Ashgate Publishing. pp. 376, 378. ISBN 9780754672562. Archived from the original on 8 May 2018.
^ "Airport Categories". Federal Aviation Administration. 3 March 2016. Archived from the original on 28 May 2016. Retrieved 30 May 2016.
^ ^a ^b ^c ^d Cook, Gerald; Goodwin, Jeremy (2008). "Airline Networks: A Comparison of Hub-and-Spoke and Point-to-Point Systems". Journal of Aviation/Aerospace Education & Research. 17 (2). Embry–Riddle Aeronautical University: 52–54. Archived from the original on 23 September 2015. Retrieved 28 May 2016.
^ ^a ^b ^c ^d "Airline Deregulation and Hub-and-Spoke Networks". The Geography of Transport Systems. Hofstra University. Archived from the original on 5 April 2016. Retrieved 28 May 2016.
^ Schmidt, William (14 November 1985). "Deregulation Challenges Atlanta Airline Hub". The New York Times. Archived from the original on 24 May 2015. Retrieved 28 May 2016.
^ ^a ^b ^c Lawrence, Harry (2004). Aviation and the Role of Government. Kendall Hunt. pp. 227–228. ISBN 9780757509445. Archived from the original on 15 February 2017. Retrieved 30 May 2016.
^ Reed, Ted (18 September 2018). "American Airlines Has Hubs at Three of Top Four Most-Connected U.S. Airports, Survey Says". Forbes. Retrieved 27 February 2022.
^ ^a ^b ^c Maxon, Terry (27 March 2015). "American Airlines banking on tighter connections". The Dallas Morning News. Archived from the original on 24 June 2016. Retrieved 30 May 2016.
^ ^a ^b ^c ^d ^e Belobaba, Peter; Odoni, Amedeo; Barnhart, Cynthia, eds. (2016). The Global Airline Industry. Chichester, England: John Wiley & Sons. pp. 142, 172–174. ISBN 9781118881170. Archived from the original on 8 May 2018.
^ ^a ^b Reed, Dan (8 August 2002). "American Airlines to try rolling hubs". USA Today. Archived from the original on 5 October 2016. Retrieved 30 May 2016.
^ "Qatar Airways' Doha hub analysed; three waves & 471 movements today". Airline Network News & Analysis. 9 March 2020. Archived from the original on 21 March 2020. Retrieved 13 March 2020.
^ "These Are the 20 Busiest Airports in the United States". AFAR. 28 August 2023. Retrieved 13 November 2023.
^ "USDOT Bureau of Transpoirtation Statistics Data Elements". United States Department of Transportation. Retrieved 13 November 2023.
^ "Sea–Tac Airport Annual Activity Report". Port of Seattle. 15 April 2018. Archived from the original on 22 July 2018. Retrieved 22 July 2018.
^ ^a ^b ^c Al-Sayeh, Karim (2014). The Rise of the Emerging Middle East Carriers: Outlook and Implications for the Global Airline Industry (PDF) (MSc thesis). Massachusetts Institute of Technology. pp. 25–26, 28. Archived from the original (PDF) on 29 May 2016. Retrieved 28 May 2016.
^ Kindergan, Ashley (2 January 2015). "Revisiting: The Rise of the Gulf Carriers". The Financialist. Credit Suisse. Archived from the original on 21 April 2016. Retrieved 28 May 2016.
^ Dewey, Caitlin (5 March 2013). "The changing geography of international air travel". The Washington Post. Archived from the original on 8 August 2016. Retrieved 28 May 2016.
^ Scholes, Kevan (2004). Federal Express – delivering the goods (PDF) (Report). Pearson PLC. Archived from the original (PDF) on 11 June 2014. Retrieved 29 May 2016.
^ "Hubs of Major Air Freight Integrators". The Geography of Transport Systems. Hofstra University. Archived from the original on 12 April 2016. Retrieved 29 May 2016.
^ ^a ^b Denby, Sam (13 February 2018). "How Overnight Shipping Works". Archived from the original on 13 December 2021. Retrieved 4 March 2021 – via YouTube.
^ McWhirter, Alex (27 November 2015). "Jet Airways to axe Brussels hub". Business Traveller. Archived from the original on 12 December 2015. Retrieved 29 May 2016.
^ "Ahmedabad to Newark via London". airindia.in. Archived from the original on 7 March 2018. Retrieved 8 May 2018.
^ André Orban (27 March 2016). "Jet Airways officially launches flights from Amsterdam Schiphol". Aviation24.be. Retrieved 11 December 2021.
^ "The JetBlue focus cities" (PDF). JetBlue. Archived from the original (PDF) on 18 February 2015. Retrieved 26 May 2016.
^ Mammarella, James (2014). "Airport Hubs". In Garrett, Mark (ed.). Encyclopedia of Transportation: Social Science and Policy. SAGE Publications. ISBN 978-1-4522-6779-1. Archived from the original on 8 May 2018.
^ Heilman, Wayne (20 April 2012). "Springs is Frontier's new front in battle for Colorado travelers". The Gazette (Colorado Springs). Archived from the original on 26 May 2016. Retrieved 26 May 2016.
^ Mutzabaugh, Ben (3 March 2006). "United adds a 'hublet' in San Antonio". USA Today. McLean: Gannett. Archived from the original on 26 May 2016. Retrieved 26 May 2016.
^ Mammarella, James (2014). "Airport Hubs". In Garrett, Mark (ed.). Encyclopedia of Transportation: Social Science and Policy. SAGE Publications. ISBN 9781452267791. Archived from the original on 8 May 2018.
^ Rose, Mark; Seely, Bruce; Barrett, Paul (2006). The Best Transportation System in the World: Railroads, Trucks, Airlines, and American Public Policy in the Twentieth Century. Columbus, Ohio: Ohio State University. p. 233. ISBN 9780812221169. Archived from the original on 8 May 2018.
^ Credeur, Mary; Schlangenstein, Mary (3 May 2012). "United Fights Southwest in Texas to Keep Grip on Busy Hub". Bloomberg News. Archived from the original on 29 May 2016. Retrieved 28 May 2016.
^ Thompson, David; Perkins, Stephen; van Dender, Kurt; Zupan, Jeffrey; Forsyth, Peter; Yamaguchi, Katsuhiro; Niemeier, Hans-Martin; Burghouwt, Guillaume (2014). Expanding Airport Capacity in Large Urban Areas. ITF Round Tables. OECD Publishing. pp. 151–152. doi:10.1787/2074336x. ISBN 9789282107393. Archived from the original on 8 May 2018. Retrieved 29 May 2016.

[2] Colloquially, an airline hub may be defined as an airport that receives many passengers or as an airport that serves as the operating base of an airline, whether or not the airline allows for connecting traffic.^[1]

[4] The Federal Aviation Administration of the United States defines a hub in terms of passenger enplanements. Specifically, a hub is an airport that handles 0.05% or more of the nation's annual passenger boardings.^[1]^[2]

[17] Alaska Airlines: 11.4^[14]

[holloway-1] Holloway, Stephen (2008). Straight and Level: Practical Airline Economics (3rd ed.). Ashgate Publishing. pp. 376, 378. ISBN 9780754672562. Archived from the original on 8 May 2018.

[3] "Airport Categories". Federal Aviation Administration. 3 March 2016. Archived from the original on 28 May 2016. Retrieved 30 May 2016.

[erau-5] Cook, Gerald; Goodwin, Jeremy (2008). "Airline Networks: A Comparison of Hub-and-Spoke and Point-to-Point Systems". Journal of Aviation/Aerospace Education & Research. 17 (2). Embry–Riddle Aeronautical University: 52–54. Archived from the original on 23 September 2015. Retrieved 28 May 2016.

[hofstra-6] "Airline Deregulation and Hub-and-Spoke Networks". The Geography of Transport Systems. Hofstra University. Archived from the original on 5 April 2016. Retrieved 28 May 2016.

[7] Schmidt, William (14 November 1985). "Deregulation Challenges Atlanta Airline Hub". The New York Times. Archived from the original on 24 May 2015. Retrieved 28 May 2016.

[govt-8] Lawrence, Harry (2004). Aviation and the Role of Government. Kendall Hunt. pp. 227–228. ISBN 9780757509445. Archived from the original on 15 February 2017. Retrieved 30 May 2016.

[Forbes-9] Reed, Ted (18 September 2018). "American Airlines Has Hubs at Three of Top Four Most-Connected U.S. Airports, Survey Says". Forbes. Retrieved 27 February 2022.

[dallas-10] Maxon, Terry (27 March 2015). "American Airlines banking on tighter connections". The Dallas Morning News. Archived from the original on 24 June 2016. Retrieved 30 May 2016.

[belobaba-11] Belobaba, Peter; Odoni, Amedeo; Barnhart, Cynthia, eds. (2016). The Global Airline Industry. Chichester, England: John Wiley & Sons. pp. 142, 172–174. ISBN 9781118881170. Archived from the original on 8 May 2018.

[american2002-12] Reed, Dan (8 August 2002). "American Airlines to try rolling hubs". USA Today. Archived from the original on 5 October 2016. Retrieved 30 May 2016.

[13] "Qatar Airways' Doha hub analysed; three waves & 471 movements today". Airline Network News & Analysis. 9 March 2020. Archived from the original on 21 March 2020. Retrieved 13 March 2020.

[14] "These Are the 20 Busiest Airports in the United States". AFAR. 28 August 2023. Retrieved 13 November 2023.

[15] "USDOT Bureau of Transpoirtation Statistics Data Elements". United States Department of Transportation. Retrieved 13 November 2023.

[16] "Sea–Tac Airport Annual Activity Report". Port of Seattle. 15 April 2018. Archived from the original on 22 July 2018. Retrieved 22 July 2018.

[mit-18] Al-Sayeh, Karim (2014). The Rise of the Emerging Middle East Carriers: Outlook and Implications for the Global Airline Industry (PDF) (MSc thesis). Massachusetts Institute of Technology. pp. 25–26, 28. Archived from the original (PDF) on 29 May 2016. Retrieved 28 May 2016.

[19] Kindergan, Ashley (2 January 2015). "Revisiting: The Rise of the Gulf Carriers". The Financialist. Credit Suisse. Archived from the original on 21 April 2016. Retrieved 28 May 2016.

[20] Dewey, Caitlin (5 March 2013). "The changing geography of international air travel". The Washington Post. Archived from the original on 8 August 2016. Retrieved 28 May 2016.

[21] Scholes, Kevan (2004). Federal Express – delivering the goods (PDF) (Report). Pearson PLC. Archived from the original (PDF) on 11 June 2014. Retrieved 29 May 2016.

[22] "Hubs of Major Air Freight Integrators". The Geography of Transport Systems. Hofstra University. Archived from the original on 12 April 2016. Retrieved 29 May 2016.

[:0-23] Denby, Sam (13 February 2018). "How Overnight Shipping Works". Archived from the original on 13 December 2021. Retrieved 4 March 2021 – via YouTube.

[24] McWhirter, Alex (27 November 2015). "Jet Airways to axe Brussels hub". Business Traveller. Archived from the original on 12 December 2015. Retrieved 29 May 2016.

[25] "Ahmedabad to Newark via London". airindia.in. Archived from the original on 7 March 2018. Retrieved 8 May 2018.

[26] André Orban (27 March 2016). "Jet Airways officially launches flights from Amsterdam Schiphol". Aviation24.be. Retrieved 11 December 2021.

[jetblue-27] "The JetBlue focus cities" (PDF). JetBlue. Archived from the original (PDF) on 18 February 2015. Retrieved 26 May 2016.

[encyclo-28] Mammarella, James (2014). "Airport Hubs". In Garrett, Mark (ed.). Encyclopedia of Transportation: Social Science and Policy. SAGE Publications. ISBN 978-1-4522-6779-1. Archived from the original on 8 May 2018.

[29] Heilman, Wayne (20 April 2012). "Springs is Frontier's new front in battle for Colorado travelers". The Gazette (Colorado Springs). Archived from the original on 26 May 2016. Retrieved 26 May 2016.

[30] Mutzabaugh, Ben (3 March 2006). "United adds a 'hublet' in San Antonio". USA Today. McLean: Gannett. Archived from the original on 26 May 2016. Retrieved 26 May 2016.

[31] Mammarella, James (2014). "Airport Hubs". In Garrett, Mark (ed.). Encyclopedia of Transportation: Social Science and Policy. SAGE Publications. ISBN 9781452267791. Archived from the original on 8 May 2018.

[32] Rose, Mark; Seely, Bruce; Barrett, Paul (2006). The Best Transportation System in the World: Railroads, Trucks, Airlines, and American Public Policy in the Twentieth Century. Columbus, Ohio: Ohio State University. p. 233. ISBN 9780812221169. Archived from the original on 8 May 2018.

[33] Credeur, Mary; Schlangenstein, Mary (3 May 2012). "United Fights Southwest in Texas to Keep Grip on Busy Hub". Bloomberg News. Archived from the original on 29 May 2016. Retrieved 28 May 2016.

[34] Thompson, David; Perkins, Stephen; van Dender, Kurt; Zupan, Jeffrey; Forsyth, Peter; Yamaguchi, Katsuhiro; Niemeier, Hans-Martin; Burghouwt, Guillaume (2014). Expanding Airport Capacity in Large Urban Areas. ITF Round Tables. OECD Publishing. pp. 151–152. doi:10.1787/2074336x. ISBN 9789282107393. Archived from the original on 8 May 2018. Retrieved 29 May 2016.

[a]

[b]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[c]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

[22]

[23]

[24]

[25]

[26]

[27]

[28]

[29]

[30]

[31]

[1]

[2]

[14]

v t e Commercial aviation
Airlines	Airline codes Airline holding companies Cargo airline Charter airlines Flag carriers Low-cost airlines Non-scheduled airline Passenger airlines Regional airlines
Alliances	Oneworld SkyTeam Star Alliance Value Alliance Vanilla Alliance U-FLY Alliance
Trade groups	International ACO ATAG IATA IATAN IFALPA ISTAT United States A4A RAA Europe A4E ASD ECA EBAA ERA ETWF Other regions AACO AAPA AFRAA RAAA
Aircrew	Pilot in command (Captain) First officer Second officer Third officer Relief crew Flight attendant Flight engineer Loadmaster Aircraft pilot Purser Dead mileage
Airliner	Travel class First class Business class Premium economy class Economy class Basic economy class Aircraft cabin Aircraft lavatory Aircraft seat map Airline meal Airline seat Buy on board Crew rest compartment In-flight entertainment Inflight smoking Galley Sickness bag
Airport	Aerodrome Airline hub Airport check-in Airport lounge Airport rail link Airport terminal Airside pass Airstair Boarding Domestic airport Gate International airport Jet bridge Low-cost carrier terminal Runway Transit hotel
Customs / Immigration	Arrival card Border control (internal) Departure card Passport Timatic Travel document Travel visa (Electronic)
Environmental effects	Hypermobility Environmental effects of aviation
Law	Air transport agreement Air route authority between the United States and China Bermuda Agreement (UK–US, 1946–1978) Bermuda II Agreement (UK–US, 1978–2008) Cross-strait charter Beijing Convention Cape Town Treaty Chicago Convention Convention on the Marking of Plastic Explosives European Common Aviation Area Flight permit Freedoms of the air EU–US Open Skies Agreement Hague Hijacking Convention Hague Protocol Montreal Convention Paris Convention of 1919 Rome Convention Sabotage Convention Tokyo Convention Warsaw Convention
Intergovernmental organizations	ICAO ECAC Eurocontrol EASA ENCASIA
Baggage	Bag tag Baggage allowance Baggage carousel Baggage cart Baggage reclaim Baggage handler Baggage handling system Baggage sizer Checked baggage Hand luggage Lost luggage (WorldTracer) Luggage lock
Aviation safety	Air rage Air traffic control Air traffic service Aircraft safety card Airport authority Airport crash tender Airport police Airport security Airspace class Area control center Brace position Civil aviation authority Control area Control zone Controlled airspace Evacuation slide Flight information region Flight information service Flight recorder Instrument flight rules Overwing exits Pre-flight safety demonstration Sky marshal Special use airspace Special visual flight rules Terminal control area Terminal control center Uncontrolled airspace Upper information region Visual flight rules
Airline tickets	Airline booking ploys Airline reservations system Airline ticket Airline timetable Bereavement flight Boarding pass Codeshare agreement Continent pass Electronic ticket Fare basis code Flight cancellation and delay Frequent-flyer program Government contract flight One-way travel Open-jaw ticket Overbooking (Overselling) Passenger name record Red-eye flight Round-the-world ticket Standby Tracking Travel agency Travel website
Ground crew	Aircraft maintenance technician Aircraft ground handling Baggage handler Flight dispatcher
Miscellaneous	Air cargo Air travel Aviation taxation and subsidies Mile high club