Airline hubs or hub airports are used by one or more airlines to
concentrate passenger traffic and flight operations at a given
airport. They serve as transfer (or stop-over) points to get
passengers to their final destination.[a][b] It is part of the
hub-and-spoke system. An airline operates flights from several non-hub
(spoke) cities to the hub airport, and passengers traveling between
spoke cities need to 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.
1 Focus city
3 Types of hubs
3.1 Cargo hub
3.2 Focus city
3.3 Fortress hub
3.4 Primary and secondary hubs
3.5 Reliever hub
3.6 Scissor hub
3.7 Moonlight hub
4.1 Middle East
4.2 United States
5 See also
The focus cities of
JetBlue are Boston, Fort Lauderdale, Long Beach,
New York (JFK), Orlando and San Juan
In the airline industry, a focus city is a destination from which an
airline operates several point-to-point routes. Thus, a focus city
primarily caters to the local market rather than to connecting
However, with the term's expanded usage, a focus city may also
function as a small-scale hub.
Southwest Airlines are examples of US-based
airlines that consider some of their destinations to be focus
The hub-and-spoke system allows an airline to serve fewer routes, so
fewer aircraft are needed. 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. 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. In addition, airlines may experience
capacity constraints as they expand at their hub airports.
For the passenger, the hub-and-spoke system offers one-stop air
service to a wide array of destinations. However, it requires
having to regularly make connections en route to their final
destination, which increases travel time. Additionally, airlines
can come to monopolise their hubs (fortress hubs), allowing them to
freely increase fares as passengers have no alternative.
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. However, an airline must assemble a large number of
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. In addition, banking could result in inefficient
aircraft utilisation, with aircraft waiting at spoke cities for the
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".
While costs may decrease, connection times are longer at a rolling
American Airlines was the first to depeak its hubs,
trying to improve profitability following the September 11
attacks. It rebanked its hubs in 2015, however, feeling the gain
in connecting passengers would outweigh the rise in costs.
Types of hubs
FedEx Express aircraft at Memphis International Airport
The primary hub of
British Airways is Heathrow
Airport in London
The hub-and-spoke system is also used by some cargo airlines. FedEx
Express established its main hub in Memphis 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.
Other airlines that use this system include UPS Airlines, TNT Airways,
Cargolux and DHL Aviation, which operate their primary hubs at
Louisville, Liège, Luxembourg and Leipzig respectively.
Although the term focus city used to mainly refer to an airport from
which an airline operates several point-to-point routes, its usage has
expanded to refer to a small-scale hub as well. For example,
JetBlue's New York–JFK focus city, which is the airline's busiest
operation, functions like a 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. Examples include Delta hubs at
Atlanta, Detroit and Minneapolis–Saint Paul;
American Airlines hubs
at Charlotte, Dallas–Fort Worth and Philadelphia; and United hubs at
Denver, Houston–Intercontinental and Newark.
Flag carriers have historically enjoyed similar dominance at the main
international airport of their countries and some still do. Examples
Lufthansa at Frankfurt Airport,
KLM at Amsterdam Airport
British Airways at
Air China at Beijing
Capital Airport, and
Air France at
Paris Orly and Charles de Gaulle
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 Turkish Airlines' Istanbul–Sabiha Gökçen hub,
British Airways' hub at London-Gatwick, Air India's hub at
Lufthansa's hub at Munich. By operating multiple hubs, airlines can
expand their geographic reach. They can also better serve
spoke–spoke markets, providing more itineraries with connections at
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.
A scissor hub occurs when an airline operates multiple flights to an
airport that arrive at the same time, swap passengers, and then
continue to their final destination.
Jet Airways has a scissors
hub in Amsterdam, where passengers fly in from Delhi,
Mumbai to connect onto the flight to
Toronto and vice versa. Air
India operates a similar scissor hub at London's Heathrow Airport,
where passengers from Delhi, Ahmedabad, and
Mumbai can continue onto a
flight to Newark. 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
WestJet Airlines uses St. John's as a scissor hub during its summer
schedule for flights inbound from Ottawa and
Toronto and outbound to
In past history, carriers have maintained niche, time-of-day
operations at hubs. The most notable is America West's use of McCarran
Airport in Las Vegas as a primary night-flight hub to
increase aircraft utilization rates far beyond those of competing
Emirates aircraft at
Dubai International Airport
In 1974, the governments of Bahrain, Oman,
Qatar and the United Arab
Emirates took control of
Gulf Air from the British Overseas Airways
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.
Observing the success of Emirates,
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
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.
Qatar Airways and
Etihad Airways have since established
large hubs at their respective home airports. The hubs, which benefit
from their proximity to large population centres, have become
popular stopover points on trips between Europe and Asia, for
example. Their rapid growth has impacted the development of
traditional hubs, such as London, Paris, and New York City.
Before the US airline industry was deregulated in 1978, most airlines
operated under the point-to-point system. 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
Delta Air Lines
Delta Air Lines was the first to implement such a system,
providing service to remote spoke cities from its Atlanta hub.
After deregulation, many airlines quickly established hub-and-spoke
route networks of their own.
US majors top 12 airports
(Departing seat capacity in millions, 2017)
New York JFK
Salt Lake City
Hidden city ticketing
List of former airline hubs
List of hub airports
^ Colloquially, an airline hub may be defined as an airport that
receives a large number of passengers or as an airport that serves as
the operating base of an airline, whether or not the airline allows
for connecting traffic.
Federal Aviation Administration
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
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