When Singapore revealed that it had chosen the Gulfstream G550 business jet as its new airborne early warning (AEW) platform last April, Northrop Grumman officials were reportedly shocked. They had every confidence that the Republic of Singapore Air Force (RSAF) would select the E-2D, an upgraded version of the Hawkeye twin turboprop that had served the RSAF well for nearly 20 years.

But as Singapore Minister for Defence Teo Chee Hean noted when he announced the choice, “The G550-AEW with its high operating altitude of 41,000 feet enjoys an unhindered radar detection of more than 200 nautical miles.” Singapore is also believed to have evaluated and rejected another twin-turboprop-based AEW solution, the Saab Erieye.

That is not the full story, though. Singapore will receive four G550s after modification by IAI Elta Systems into the Conformal Airborne Early Warning & Control (CAEW) system. Four similar aircraft are now entering service with the Israeli Air Force, where they are known as the Eitam (Fish Eagle).

At a conference in London in December, Avishai Izhakian, deputy general manager of IAI Elta’s AEW Division, gave an aggressive briefing on the merits of the EL/W-2085 integrated sensor suite that forms the heart of the CAEW system. “We bring a different attitude and considerable innovation. We do things in months that our competitors take years to develop,” he claimed.

These short development cycles have allowed Elta to take full advantage of the tremendous advance of electronics processing technology, which at the same time has provided significant reductions in weight and size, he added. “It’s a very simple algorithm to transform kilograms into kilobytes,” Izhakian said.

The CAEW system provides 360-degree coverage through two very large active arrays faired to each side of the fuselage, operating in L-band, in addition to smaller antennas in the nose and tail looking fore-and-aft, operating in S-band. The side-looking arrays generate most of the tracks; the shorter-range fore-and-aft lookers help maintain the track quality.

This is a unique configuration that Elta has been working toward for 25 years, starting with the Boeing 707-based Phalcon system that looked fore-and-aft only and continuing with an Il-76 testbed. Izhakian noted that Elta has also developed “very advanced phased-array radar technology” for warships and air-surface missiles.
According to Elta, the radar provides accurate 3-D tracks, low false-alarm rate, flexible and high revisit rate, electronic counter-countermeasures and programmable search-and-track regimes. But Izhakian noted that in the CAEW system, communications are even more important than the radar.

“This is a big change over earlier systems,” he pointed out. The CAEW includes U/VHF, HF, satcom, VOIP, secure voice, integrated intercom and a secure datalink. “There is full connectivity with other air, land and sea systems for network-centric warfare,” Izhakian said.

The system also includes a full Signals Intelligence sensor suite that provides high probability of signal interception and high bearing accuracy. The electronic intelligence subsystem of this suite additionally fulfills a radar warning function, and is therefore integrated with the aircraft’s self-protection system. This also consists of a missile approach warning system that employs radar and IR technologies; a chaff and flares dispenser; and directional infrared countermeasures.

The G550 CAEW carries six workstations for the operators, who are provided with 24-inch Windows-based displays. Each workstation can perform command and control tasks, as well as AEW. The whole system is built on an open architecture. “The machine works for the operator, not the other way round,” said Izhakian.

After four months of aerodynamic flight testing in the U.S., Gulfstream Aerospace delivered the first G550 CAEW to Israel in September 2006. The EL/W-2085 system was installed by IAI’s Bedek Division. Intensive airborne trials took place throughout last year. Meanwhile, IAI installed and commissioned a mission simulator plus planning and debriefing systems at the squadron base. The CAEW is due to achieve initial operating capability in the Israeli Air Force by the end of this month.