Eight versions of the Gulfstream II and IV variants are currently in service with the USAF, Army and Marine Corps with the general designation of C-20. However, one version of the Gulfstream IV that is rarely seen is the USAF C-20C, which isn't listed in anywhere and is part of a classified programme. Three C-20C aircraft (85-0050 c/n 456, 85-0049 c/n 473 and 86-0403 c/n 473) are based at Andrews AFB in Maryland and are operated by the Presidential Airlift Group (PAG) of the 89th Airlift Wing. The C-20C aircraft are part of a secret programme known as COOP (Continuity Of government Operations Programme) and are used to transport the President and other VVIPs in the event of a national emergency. The three C-20C aircraft are equipped with a comprehensive communication system installed by E-Systems and designed to enable operations in a post-nuclear environment. As part of this rol, whenever the US President or another VVIP travels anywhere in Air Force One, a C-20C is usually positioned discretely at an adjacent airfield, just in case the President or VVIP has to suddenly depart in a hurry and Air Force One has been disabled.
However, Gulfstream Aerospace, now owned by General Dynamics, hasn’t been sitting on it’s laurels and have been busy pitching new versions of their celebrated business jets for a variety of military programmes.
G450 – As part of their effort to secure the contract to develop the US Army’s Aerial Common Sensor (ACS) ISR system, one of the competitors, Northrop Grumman, has selected Gulfstream as a partner, using the Gulfstream G450. Northrop Grumman have already been given the G450 (IV-SP) version they’re proposing for the ACS contract the unofficial designation RC-20. The ACS will replace both the RC-7 ARL and the RC-12 Guardrail reconnaissance systems and is scheduled to become operational in 2009, with a total of 35 aircraft eventually fielded by 2017.
G500 – Gulfstream are offering air forces a version of the G500 long-range business jet, designated the EC-37SM, as an economic off-the-shelf ELINT and Special Mission solution. Offering the capability of providing ELINT, targeting and other special missions currently fulfilled by large airliner platforms. Some concepts show the aircraft with either 2 or 4 under-wing pods and a large canoe-shaped equipment pod underneath the forward fuselage. As well as ELINT payloads, the aircraft could carry a radar in the canoe, similar to the UK’s ASTOR, providing an AEW and SAR/GMTI capability, as well as an EO/IR surveillance pod. A stand-off electronic attack version would be equipped with EW pods, towed decoys and SIGINT equipment.
G550 UAV – Although the Northrop Grumman Global Hawk UAV would appear to have the inside track, in its attempt to win the US Navy’s Broad Area Maritime Surveillance (BAMS) requirement, Gulfstream have decided to enter the fray with an unmanned version of the G550 business jet. BAMS is intended to provide the USN with an unmanned adjunct to the follow-on Multi-mission Maritime Aircraft replacement for the P-3C Orion. Designated the RQ-37, the vehicle would offer between 3 and 4 times the payload of the Global Hawk, over 15 hours endurance and the redundancy of twin engines. However, apart for considerably less endurance, the biggest drawback of the RQ-37 proposal is cost – the Global Hawk should come in around $24-25 million whilst a basic, unequipped G5000 sells for around $35 million. Although the ‘off-the-shelf’ RQ-37 solution certainly has possibilities, given the cost and proven success of the Global Hawk, I would be very surprised if this programme ever gets off the ground.
Since Oct 73 the Israeli Air Force (IAF) has operated a number of Boeing 707 aircraft based at Lod Airport as 120 Sqn. The aircraft operated by the IAF were all initially operated by El Al, the state airline and were initially acquired to provide an air transport capability; however, it soon became obvious that the 707 was an ideal platform for a whole variety of additional roles. By 1976 a number of 707’s had been equipped to operate as Command, Control & Communications (C³) airborne command posts, but to make the most effective use of the aircraft they also included a basic SIGINT and ECM capability. In 1976 E Systems of Greenville, Texas converted four IAF 707s into dedicated SIGINT aircraft, two aircraft were fitted with equipment similar to the USAF RC-135U Combat Sent and the other two were fitted with a similar capability to the RC-135W Rivet Joint. Since then the IAF have modified a number of other 707’s to undertake the SIGINT role, but the IAF are very reluctant to release any information or official photographs of their SIGINT 707’s. However, the possible existence of an IAF AEW 707 is even less clear.
In 1976, to meet the IAF’s AEW needs, four AEW Grumman E-3C’s were ordered and although these aircraft performed well, they were optimised for an ‘over-sea’ role and despite many modifications they were expensive to operate and never quite met the IAF’s and in 1996 they withdrew their Hawkeye’s from active service. The IAF’s apparent lack of an effective AEW aircraft since 1996 is something of a mystery, particularly as back in 1994 IAI delivered one Boeing 707 equipped with the Phalcon system to Chile, demonstrating that they had the capability for this complex undertaking. Although it has never been officially confirmed that the IAF have a Phalcon equipped 707 and despite the lack of photographs, it would be very odd for them not to have at least one or possible two aircraft fitted with the Phalcon system, if only for ‘development’ purposes – time will tell.
However, the IAF’s Boeing 707’s are now approaching the end of their useful lives and like all aging aircraft are becoming increasingly expensive to operate and maintain. On 1 Dec 2001, to replace their Boeing 707’s, the IAF ordered four Gulfstream G550 and once delivered to Israel the aircraft will then be fitted with specialised equipment by IAI.. In IAF service the G550 will be known as Nachshon (Pioneer) and the first bare airframe is scheduled to arrive in Israel by the end of 2004.
IAI Elta division will install a compact version of the Phalcon AEW&C system on 3 ac of the 4 aircraft. This ‘compact Phalcon’ system, believed to be known as the IAI Elta EL/W-2085, is derived from both the full-scale Phalcon system and the Green Pine fire control radar developed for the Arrow anti-tactical ballistic missile system and will consist of four phased array radar antennas, giving 360º degree coverage. Inside the fuselage at the rear of the aircraft will be six operator stations. The aircraft will also be quipped with ESM antennas ahead of the cockpit, in small wingtip pods and under rear Phalcon radome. A SATCOM antenna will be inside a fairing on top of the tail enabling a near real-time data link to command headquarters.
However the first G550 to arrive in Israel will be converted by IAI into a specialised SIGINT aircraft and fitted with the IAI EltaEL/1-3001 system. It may see unusual that only one G550 aircraft is being equipped for SIGINT duties, however, Israel also operates a number of Raytheon RC-12 aircraft, as well as a number of UAV’s and tethered aerostats, in the SIGINT role and so they probably simply want to give themselves another option if long-range activities are required as the basic G550 can reach 51,000ft and has a range 6750nm at 0.8 Mach. All of the G550 Nachshon aircraft will operate out of Nevatim air base in the Negev, perhaps by a re-located 120 Sqn. Israel retains the options for two further G550 aircraft and, provided the IAI equipment performs as expected, I imagine this option will be taken up at some stage in the future. In total the entire deal could be worth up to $473 million.
The market for an AEW / SIGINT aircraft smaller than the costly Boeing 707/767 is growing all the time as more and more countries realise that the capability of their other expensive air assets are severely limited without the intelligence such aircraft can provide. Gulfstream and IAI are keen to develop a compact AEW system and a SIGINT option for the G550, ensuring they can then compete alongside the SAAB 2000 AEW or Embraer EMB-145 AEW in the emerging markets of South America and the Pacific Rim, as well as in the Middle East where Saudia Arabia are already looking to replace their large Boeing E-3A aircraft with something much smaller and more economic. If the G550 performs as anticipated, I would imagine many more specially equipped G550s will be appearing in various air forces over the next decade.