In-Flight Connectivity (IFC) is a service that provides Internet to aircraft passengers during a flight through an onboard local wireless network, typically Wi-Fi. Since 2004, numerous airlines have integrated this access into their in-flight entertainment offerings (collectively known as In-Flight Entertainment & Connectivity, or IFEC), which are delivered wirelessly to customer-owned Personal Entertainment Devices such as smart phones and tablets, or via a wired network connection to in-seat screen systems. The range of in-flight services offered by airlines varies significantly. Some airlines provide completely free and unlimited access, while others may offer complimentary limited service exclusively for instant messaging, with additional fees for other services or navigation packages during the flight. Market research specialized in customer behavior indicates that this service can influence a passenger's choice of airline, positioning it as a new competitive factor within the passenger air transport industry.
In 2001, Connexion by Boeing had plans to provide Internet connectivity on a number of U.S. airlines. However, broader economic challenges for the airlines industry following the September 11 attacks led to these plans being cancelled.
As of January 15, 2003, Lufthansa, the German airline, became the first airline globally to provide in-flight Internet service to its passengers, following a series of preliminary tests and through an alliance with Connexion by Boeing, which began developing in-flight Internet connections using Ethernet and 802.11 Wi-Fi. The inaugural commercial flight featuring this service operated from Frankfurt Airport to Washington Dulles, in the United States, aboard the airline's Boeing Sachsen-Anhalt aircraft.
In December 2013, JetBlue became the first airline in the United States to offer free Internet access on some of its domestic flights.
While the term Wi-Fi is often incorrectly and generically used to mean Internet access, it is important to distinguish between the two, as the former is a wireless connection between the end user device and a local network, and does not always imply that Internet access is available via that network. This distinction is especially important when dealing with publicly accessible wireless networks such as those on aircraft and cruise ships that offer local services over Wi-Fi without requiring access beyond the vessel. Internet access is often considered a premium/paid service in these scenarios.
Internet connectivity is typically available from gate to gate on commercial aircraft equipped with a satellite connection, although on aircraft that use legacy cellular Air-to-Ground (ATG) connections, it is deactivated during takeoff and landing or below 10,000 feet. Passengers can connect to the Internet aboard the aircraft via Wi-Fi. The speed and coverage of the Internet connection during the flight may vary based on the specific systems and technologies used by the airline. Typically, the Wi-Fi network uses open access without a pre-shared key and is unencrypted, which carries some security and privacy risks for applications that do not use SSL at the application level. Some IT security experts consistently recommend implementing precautions such as utilizing antivirus software, VPNs, and other network security measures when using this network, although modern operating platforms inherently mitigate many of these risks.
The growing use of Wi-Fi on personal devices by travelers is enabling airlines to eliminate in-seat screens, resulting in fuel savings and reduced aircraft weight.
In addition to offering internet access to passengers, some airlines also use the IFC system to provide operational Internet connectivity to the cabin and flight crews via Electronic flight bag devices, as well as for maintenance and ground crews.
A typical commercial airliner will have between 2 and 6 cabin wireless access points (CWAPs) depending on the size of the aircraft to provide wireless connectivity to passengers and crew. These CWAPs are typically based on off-the-shelf enterprise-grade APs that have been modified and certified to aircraft standards for safety, power, connectivity, and management (such as ARINC 629). A server located in the avionics bay handles most of the local networking tasks such as DHCP addressing, DNS, routing, captive portal, onboard content filtering, content caching, local content delivery, and other IFE functions. It will typically also have a built-in network switch to connect the various devices on the network. Internet-facing hardware is typically one or more satellite modems and antenna systems (which can be a mechanical tracking antenna or an electronically steered antenna)mounted on top of the aircraft with a clear view of the sky. Older IFC systems used an Air-to-Ground cellular modem with one or more antennas mounted on the belly of the aircraft, connecting to a dedicated network of cellular base stations on the ground. Some systems still keep a cellular modem for Out-of-band management.
Unlike the Internet service provided at airports, which is mostly free of charge, each airline determines its own fees associated with the use of Wi-Fi during a flight, which can vary from free and unlimited access to charges for data packages or daily passes for browsing. As of 2024, the airlines providing complimentary in-flight Wi-Fi service for all classes are:
These airlines allow free access to Wi-Fi on board for passengers who have previously signed up for a loyalty program, such as a frequent-flyer program: