July 27, 2015:
Italy is renewing its lease on its only SIGINT (signals intelligence) aircraft, mainly because of the continuing and growing problem with people smugglers operating out of Libya and trying to bring several hundred thousand illegal migrants to Italy. SIGINT aircraft are equipped to monitor all sorts of wireless communications and are a key tool in keeping track of what the smuggling gangs are up to. The SIGINT aircraft was built by an American firm, using a modified Gulfstream III business jet. This 30 ton twin-jet aircraft normally carries a crew of two and up to 19 passengers. Outfitted for SIGNINT most of the internal space is taken up by electronics, monitored by about four system operators while the two pilots keep the aircraft in the air for up to eight hours per sortie. Italy began leasing the Gulfstream III SIGINT aircraft in 2012 because the air force could not afford to buy it. The Italian deal involved paying for hours (in the air) used and was a lot cheaper than buying.
These are not the only militarized business jets Italy uses. In 2012 Italy bought two Israeli AWACS (Airborne Early Warning Aircraft) for $375 million each. Italy didn’t have a choice in this case as this was part of the offset for the recent Israeli purchase of $993 million worth of Italian jet trainers. Israel also calls this aircraft CAEW (Conformal Airborne Early Warning).
In 2008 Israel introduced this new AWACS design which used a long range business jet (the 40 ton Gulfstream G550) fitted out with Israeli made radar and electronics. The Israeli Air Force bought the CAEW 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. Singapore later bought four CAEWs.
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 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.
The Phalcon radar is, in some respects, superior to the one used in the American AWACS. For example, Phalcon uses a phased array radar (thousands of small radar transmitters are fitted underneath the aircraft). The phased array radar, in combination with the latest, most powerful computers and other antennas for picking up a variety of signals, enables Phalcon to be more aware of what electronic equipment (airborne or on the ground) is operating up to 400 kilometers away. The phased array radar allows positions of aircraft on operator screens to be updated every 2-4 seconds, rather than every 20-40 seconds as is the case on the United States AWACS (which uses a rotating radar in a radome atop the aircraft). The first Phalcon system was fitted on a Boeing 707, although somewhat limited versions could be put onto a C-130. On a larger aircraft you can have more computers, and other electronics, as well as more human operators. But the major advantage of the Phalcon is that it is a more modern design. The U.S. AWACS is over twenty years old and has undergone upgrades to the original equipment. The Israeli air force operates six Phalcon aircraft (using Boeing 707 airframes).
Business jets have proven very popular for the latest generation of electronic support aircraft, mainly because the business jets have gotten larger and the electronics smaller and lighter. Altogether it is a cheaper and more affordable package. The next generation of these support aircraft will probably be unmanned UAVs.