Boeing has been inundated by requests from business jet operators for information about its Connexion broadband satellite communications system since the widely publicized trial launch of the service in January aboard a Lufthansa 747-400. For the time being, though, the size, weight and power requirements of the phased-array antenna mean the service is unlikely to be available on any business aircraft smaller than those based on airliners with a capacity of 100 or more seats.
So far, said a Boeing spokesman, there have been 14 installations of the system aboard privately owned aircraft. Platforms equipped include the Boeing Business Jet, Boeing 757 and Airbus A340. At least two of these use the system solely for in-flight reception of satellite television broadcasts, but Boeing has used its 737-400 demonstrator for public demonstrations of video conferencing. The company is also installing Connexion on the C-32A version of the 757-200, which the U.S. Air Force uses to transport the vice president and other government officials.
Lufthansa Technik installed a receive antenna to provide satellite television reception on an Airbus A340 for a Middle East customer three years ago. That antenna was derived from an earlier model developed for a Boeing 767 installation, and the antennas fitted for trials on Lufthansa’s 747-400 represent another iteration of the same basic design. The production antennas planned for customer airlines’ aircraft are a new design under development by Mitsubishi Electric that integrates the transmit and receive functions in a single phased array. So far Lufthansa, SAS and Japan Airlines have committed to installations starting next year on their long-haul fleets, and British Airways was expected to follow suit subject to the successful outcome of a 90-day in-service trial that started February 20 on a 747-400 operating between London and New York JFK.
In the Lufthansa installation, said Lufthansa FlyNet project general manager Dr. Burkard Wigger, the antennas can continue to track the geostationary satellites that provide the communications link regardless of pitch or bank angle. Operating in the same 12.5- to 18-GHz Ku band used for terrestrial satellite television reception, they maintain a one-degree beamwidth. One beneficial byproduct of the steerable beam is that satellites that are no longer able to keep to their original position can be used.
The production antennas are designed to be usable at latitudes of up to 75 degrees north. The satellites orbit at an altitude of 22,000 miles, so there is a perceptible delay of at least 0.6 seconds between the sending of an e-mail message and receipt acknowledgment. This is a consequence of the distance the signal has to travel from airplane to Earth via the satellite, and subsequent routing through the terrestrial telecommunications network. Bandwidth capacity for the Lufthansa trial was three megabytes per second for the uplink from ground to aircraft and 128 kbps in the reverse direction, but capacity is scheduled to increase to five to 20 mbps and one megabyte per second, respectively.
In the cabin, the FlyNet service can be accessed either through in-seat Ethernet ports or through a wireless local-area network (LAN), which Lufthansa Technik developed in collaboration with Cisco Systems. The LAN has been certified by both the FAA and JAA for use on the Boeing BBJ/BBJ2 and 747-400.
By the time the service is fully operational, Lufthansa expects to allow customers to use their own laptops if they have wireless capability compatible with the IEEE 802.11b WiFi standard. But while demonstrating compliance of the LAN with airworthiness regulations was quite easy, Wigger said, gaining approval for end-user devices has proved more difficult. For the trial the airline is loaning passengers wireless laptop computers developed by Fujitsu Siemens that have been tested for compliance with electromagnetic interference standards and approved on that basis.
FlyNet avionics and cabin systems manager Jens Lehne told a workshop hosted by the World Airline Entertainment Association in London in February that Lufthansa’s approach to gaining approval for passengers to use their own wireless devices was to define a worst-case condition and demonstrate the aircraft’s immunity to it. The alternative of certifying individual devices would have involved identifying and testing every possible device, he said, an approach that would have been neither reasonable nor feasible. So the airline has worked with Boeing to identify susceptible equipment and locations, then tested them for susceptibility to emissions at a power level of 30 watts from a distance of about three feet. The immunity of Airbus aircraft to high-intensity radiated field (HIRF) interference is being addressed by a service information letter from the manufacturer and by work group 58 of the European Organization for Civil Aviation Electronics (Eurocae).
The Boeing spokesman said recent inquiries triggered by the Lufthansa trial have concerned the possibility of installing Connexion equipment on everything from Gulfstream and Bombardier business jets to Cessna Citations and in one case a Cessna 182. Others have asked about its applicability to passenger trains, emergency vehicles and yachts.
But for the time being Boeing is focused primarily on the airline market. “Down the road we’re looking at the possibility of equipment that would be suitable for Gulfstreams, Embraers and other large business jets, along with all the other potential applications,” the spokesman said. “But our focus and strategy now is to introduce it to the airline market.”
Before September 2001, Boeing was working with the three biggest U.S. airlines– American, Delta and United–on a program that was expected to equip 1,600 of their aircraft for the service–equivalent to roughly 11 percent of the world’s jetliner fleet.
But the carriers put those plans on hold as they concentrated their attention on financial survival.