Australia is buying five AISREW (Airborne Intelligence, Surveillance, Reconnaissance, and Electronic Warfare) aircraft based, like a growing number of recent electronic warfare aircraft on a long range business jet. In this case it is the 40 ton Gulfstream G550. This is part of trend as more and more such aircraft use twin-engine business jets rather than larger commercial transports (like the 707, 737 or prop-driven Constellation). This use of business jets became particularly attractive once the G550 was introduced in 2004. The five Australian AISREW aircraft will cost $260 million each including the cost of the aircraft, the electronic sensors and monitoring equipment, training and maintenance. .
The G550 became particularly popular for this sort of thing after Israel showed it could be successfully used as an AWACS (Airborne Warning and Control System) aircraft. This occurred in 2008 when Israel introduced a new AWACS design based on the G550 fitted out with Israeli made radar and electronics. The Israeli Air Force ordered these CAEW (Conformal Airborne Early Warning) AWACs in 2006 and the first two entered service in 2008. Israel had already sold the AWACS electronics to India, for installation in four Russian Il-50/76 aircraft but realized the CAEW gear could work on a smaller aircraft. Singapore, Italy, Australia and the U.S. Navy later bought four CAEWs fitted to G550s.
The CAEW AWACS carries a Phalcon conformal (it is built into the lower fuselage) phased array radar, SIGINT equipment (to capture and analyze enemy electronic transmissions), and a communications system that can handle satellite signals as well as a wide array of other transmissions. There are six personnel on board to handle all this gear, plus the flight crew. The Gulfstream G550 used for this can stay in the air for over ten hours per sortie and can fly at up to 13,200 meters (41,000 feet).
The G550 AISREW uses the same basic idea of attaching the various sensors an airborne electronic intelligence aircraft needs to the fuselage of the G550 and then put most of the electronics, plus the equipment operators, inside the aircraft. By the time the G550 appeared electronics, both sensors, computers and displays, had gotten lighter, cheaper, more reliable and more powerful. A smaller aircraft was the way to go.
The G550 is a larger version of the Gulfstream G400, which the U.S. Army uses as the C-20H transport. The U.S. Coast Guard, Air Force, and Navy also use militarized Gulfstreams (usually as C-37Vs). The 30 meter (96 foot) long aircraft has two engines and was built for long flights (over 11,000 kilometers). Current Gulfstream G550s cost about $40 million each.
In the midst of all this acquisition of new electronic surveillance aircraft Australia also shifted all its AWACS, maritime patrol and electronic warfare aircraft into one unit (the Surveillance and Response Group) during 2004. This new organization controlled all air surveillance capabilities including maritime patrol, aerospace surveillance and the development of new intelligence, surveillance and reconnaissance (ISR) and electronic warfare (EW) capabilities.