v1.2.3 / chapter 4 of 4 / 01 may 07 / greg goebel / public domain
* In the four decades since the introduction of the Grumman Mohawk, technology for battlefield surveillance has greatly improved, becoming an even more central element in battlefield operations. State of the art battlefield surveillance platforms are now "must-have" asset for any modern military force. This chapter discusses the present and future of battlefield surveillance aircraft.
* In the spring of 1999, Raytheon was awarded the contract in the $1.3 billion USD "Airborne Stand Off Radar (ASTOR)" competition for the UK. The ASTOR program was intended to develop a surveillance aircraft carrying air-to-ground radar for battlefield surveillance, similar in concept to Joint-STARS.
Raytheon's competitors for the ASTOR contract included a team led by Lockheed Martin partnered with British Aerospace; and another team led by Northrop Grumman, which proposed a joint US-UK Joint-STARS update development program. Raytheon's winning ASTOR bid may give the company an edge in sales of similar systems to other countries.
ASTOR is a joint program of the British Army and Royal Air Force (RAF). The program had its origins in the 1980s in the form of the "Corps Airborne Standoff Radar (CASTOR)" requirement for the British Army, which wanted to obtain the capability to observe Soviet military movements in Central Europe. The fall of the Soviet Union threw CASTOR into confusion, but the clear usefulness of the US Joint-STARS during the Gulf War greatly impressed the British, leading to the issue of the ASTOR requirement in the mid-1990s.
The UK is obtaining five ASTOR systems based on modified Bombardier "Global
Express" business jets, along with two portable ground sites and six tactical
ground stations mounted on trucks. Raytheon selected the Bombardier Global
Express over the comparable Gulfstream V because the Global Express has
greater cabin volume and electrical power capability. In RAF service, the
ASTOR has been given the designation of "Sentinel Reconnaissance Mark 1" or
just "Sentinel R1".
BOMBARDIER GLOBAL EXPRESS BIZJET (ASTOR BASELINE AIRCRAFT):
_____________________ _________________ _______________________
spec metric english
_____________________ _________________ _______________________
wingspan 28.5 meters 93 feet 6 inches
wing area 94.94 sq_meters 1,022 sq_feet
length 30.3 meters 99 feet 5 inches
height 7.57 meters 24 feet 10 inches
empty weight 25,400 kilograms 56,000 pounds
max loaded weight 42,400 kilograms 93,500 pounds
maximum speed 935 KPH 580 MPH / 505 KT
service ceiling 15,550 meters 51,000 feet
take-off field length 1,700 meters 5,575 feet
range, max payload 9,575 kilometers 5,945 MI / 5,170 NMI
_____________________ _________________ _______________________
The Global Express is powered by twin BMW Rolls Royce BR710-48C2
turbofans with 65.6 kN (6,690 kgp / 14,750 lbf) takeoff thrust each.
The Sentinel R1 can operate at altitudes of 15,250 meters (50,000 feet) or
higher for 11 hours. Initial plans to add inflight refueling capability were
cancelled. The aircraft has two pilots and three electronics system
officers, and additional seats and bunks for relief crews.
The primary payload is a SAR-MTI system based on the Hughes "Advanced Synthetic Aperture Radar Type 23 (ASARS-2)" radar system, used on the US Air Force U-2 reconnaissance aircraft. Marconi Radar & Countermeasures systems developed the new, larger 4.6 meter (15 foot) antenna for the ASTOR SAR system, with the antenna accommodated by a canoe fairing under the forward fuselage of the aircraft. The SAR has a low-resolution wide-area swath mode, and a spot mode for high resolution imaging of specific targets. Best resolution in spot mode from operating altitude is under 30 centimeters (1 foot). The antenna is electronically steered; it has a narrow "blind spot" in front of and behind the aircraft. Future upgrades of the radar system may add jamming / self-defense capabilities. Although there has been talk of fitting electro-optical sensors as well, that is not part of current ASTOR plans.
The Sentinel R1 has Ku-band and X-band data links for transmitting reconnaissance data, as well as a capability for "off tether" operation, storing data on board for download later. A L-3 Communications "Network Centric Collaborative Targeting (NCCT)" package performs intelligence fusion.
In the ASTOR system, the aircraft operates in conjunction with either the truck-mounted ground stations or large corps-level mobile sites. Along with increased automation, this "offload" strategy is why ASTOR only requires three systems operators, while Joint-STARS requires 17. The datalink systems have been designed with interoperability with US and NATO systems in mind. ASTOR ground systems are expected to be part of a larger network that can fuse data from other British intelligence assets on land, sea, air, and space under a scheme known as "Intelligence, Surveillance, Target Acquisition, & Reconnaissance (ISTAR)".
ISTAR will merge data from sources such as RAF Boeing E-3D Sentry AWACS aircraft; Royal Navy Sea King AEW.7 helicopters; RAF BAE Nimrod R.1 SIGINT platforms; RAF & Royal Navy tactical aircraft such as the Tornado or Harrier carrying reconnaissance pods; and the British Army's "Watchkeeper" unmanned aerial vehicles (UAVs). The merged intelligence will provided directly to command and combat elements. The British have been very interested in work conducted by the US with Joint-STARS along this line during operations in the Balkans, and will leverage off American experience.
* Initial flight of a Global Express modified with the appropriate fairings but lacking operational electronics systems took place on 3 August 2001 from the Bombardier Flight Test Center in Wichita, Kansas, with Bombardier test pilot Mark Schlegel at the controls. The initial test flights were to validate the aerodynamics of the modifications. Ventral fins were fitted under the tail to compensate for the canoe fairing.
After the initial flight, the crew reported the aircraft showed no handling peculiarities. Flight trials continued into mid-2002. This aircraft was never fitted with operational systems. An initial production aircraft was delivered to Raytheon's Greenville, Texas, facility and brought up to operational specification, performing its first flight on 26 May 2004, preparatory to being sent on to the UK for British service trials. Airframe modifications to the other four Global Express aircraft will be performed by Bombardier's Short Brothers subsidiary in Northern Ireland, with operational systems installed by the Raytheon facility in Wales. ASTOR is now in operational service with the RAF.
* The Raytheon win for ASTOR complicated US planning for Joint-STARS upgrades. The US Air Force was disappointed that their bid for a collaborative program to fulfill the ASTOR requirement with an updated Joint-STARS was rejected, but the UK needed the ASTOR capability quickly and the updated Joint-STARS program would have led to additional delays and costs.
As mentioned in the previous chapter, the Pentagon had been working on an upgrade program, the "Radar Technology Insertion Program (RTIP)", with the original intent to improve the capabilities of Joint-STARS, but technology and politics worked to change the scope and direction of the program.
The fact that the British selected a "bizjet" (the term being defined here as including both true business jets and regional jetliners) like the Global Express for ASTOR demonstrated the impact of technology improvements in battlefield surveillance aircraft. New electronic reconnaissance systems are lighter and more compact than those of a decade ago, allowing them to be carried on smaller aircraft, and such new systems are more automated, reducing the number of crew needed to operate them. Given that modern bizjets are highly refined aircraft with excellent range, performance, reliability, and low operating costs, they are now an attractive complement to larger battlefield surveillance platforms.
Similarly, the US Air Force has become increasingly committed to UAVs, particularly the service's ultra-long-range Northrop Grumman "Global Hawk". The USAF increasingly sees the Global Hawk as a valuable platform for a wide range of missions, including battlefield surveillance.
The result of this three-way tug was a change in the direction of RTIP towards "multi-platform" support, with the program's name changed appropriately to "MP-RTIP". A contract for the MP-RTIP system was awarded to Raytheon and Northrop Grumman in late 2000. Raytheon was to build the radar system itself, while Northrop Grumman handled systems integration. The Global Hawk will be the first platform to be fitted with MP-RTIP. The goal of MP-RTIP is to build a "scaleable" system that can be used on UAVs, bizjets, or a Joint-STARS-class platform. The antenna size will range from 1.5 meters (5 feet) to 6 meters (20 feet), with antenna size roughly proportional to the size of the operational platform. Antennas are built up as "aperture units", with four aperture units in the Global Hawk radar and 16 in a large-platform radar.
The current Joint-STARS SAR system is designed to track targets moving on the ground at low speed, 56 KPH (35 MPH) or less. MP-RTIP will be based on a next-generation X-band "active electronically scanned array (AESA)" system that could also track low-flying, stealthy, fast-moving missiles hundreds of kilometers away. Even the Global Hawk version of MP-RTIP is expected to be superior to the existing Joint-STARS SAR in terms of target resolution and revisit times, due to AESA technology.
An AESA can be thought of as a radio-frequency (RF) "array processor", composed of a grid of interconnected "transmit-receive" modules, each with its own RF, processing, and control electronics. The modules can work with each other to perform a wide variety of tasks -- active radar sensing, passive electronic sensing, communications, and jamming -- in an interleaved or parallel fashion. One of the advantages of an AESA is that it lends itself to a scalable design, since the array can be sized to a UAV, bizjet, or Joint-STARS-class platform by fitting fewer or more modules as required, with capability proportional to size.
Development costs will be reduced by the fact that Raytheon is currently designing similar AESA systems for US fighter aircraft, and the MP-RTIP system should be able to use much of the same technology. Total system development costs for the Global Hawk MP-RTIP system, excluding aircraft costs, are estimated at $2 billion USD.
In early 2001, the scope of the MP-RTIP program was expanded considerably. While the current focus of development efforts is still focused on an AESA-based SAR-MTI system for battlefield surveillance, the technology is seen as applicable for a wide range of applications, including surveillance or air defense based on satellite, aircraft, naval, or ground platforms. While this expansion of scope could well overwhelm the effort through "gold plating" and "creeping featurism", hopefully the current effort will remain focused on the battlefield surveillance mission, simply ensuring that the current system has "hooks" for expansion that can be exploited in incremental follow-on development efforts.
Initial flight tests of MP-RTIP were performed on a Scaled Composites Proteus aircraft beginning in 2006. The current plan is to install variants of MP-RTIP on at least three Global Hawks and five Joint-STARS platforms, but the implementation details remain a bit of a moving target.
* A derivative of MP-RTIP designated the "NATO Trans-Atlantic Radar (NATAR)" was also promoted as a solution for parallel NATO efforts to procure a "NATO Alliance Ground Surveillance (AGS)" aircraft. A competing radar, the "Stand-Off Surveillance Targeting & Acquisition Radar (SOSTAR)", was promoted by a multinational consortium with participation by EADS, Thales (formerly Thomson-CSF), FIAR of Italy, Indra of Spain, and Fokker Space of the Netherlands.
Instead of choosing one, NATO officials decided to merge NATAR and SOSTAR to create the "Transatlantic Collaborative Advanced Radar (TCAR)", similar to MP-RTIP in general concept but slightly smaller and less capable, as NATO decided that capabilities such as detecting low-flying cruise missiles were not required.
There was a considerable delay in defining the platform to carry TCAR. In 2006, a decision was made to obtain four Airbus A321 twinjets as the manned element of AGS, with production by EADS and Northrop Grumman. BAE Systems and Raytheon had proposed an alternative configuration based on the Global Express, but it didn't make the cut. Four Global Hawks will also be obtained for the AGS program.
* The development of MP-RTIP and related modern "electronic warfare (EW)" systems has led military services to wrestle with the issue of what mix they want of UAV, bizjet, or large jet platforms, and what range of surveillance and other EW functions they want these platforms to perform.
Currently battlefield surveillance, airborne early warning (AEW), jamming, and SIGINT missions are generally performed by different aircraft types, but now there is a push towards generalized EW platforms that combine some of the functions, or can be reconfigured for different EW missions. A UAV is the cheapest option, but also the most limited. Such machines are relatively small and cannot carry large payloads, restricting the size and sensitivity of SAR and other EW systems they carry. Most of the data acquired by a UAV will have to shuttled over high-speed datalinks to a ground, air, or sea based command center. A bizjet can carry larger sensors and do some onboard processing, but at present it is unclear just how much can be handled from the aircraft and how much will have to be offloaded to a command center elsewhere.
The Air Force was considering a follow-on to Joint-STARS designated the "Wide Area Surveillance (WAS)" aircraft, to go into initial service in 2010, but this scheme was gradually seen as too limited. What complicated the issue was the USAF's parallel effort to obtain a replacement for their current Boeing KC-135 aerial tanker fleet, with the Boeing 767 jetliner selected as the best option. As long as the Air Force was planning on acquiring the 767 for the tanker role, it seemed sensible to acquire it for the surveillance role as well. Initially, there was some push to actually merge the two roles to an extent, with the tankers capable of carrying a pallet of SIGINT, surveillance gear, or battlefield communications relay gear, with the pallets swapped out as required by the mission. There was talk of trying the scheme out with the existing KC-135 tanker fleet to obtain an interim capability and see how well it worked in practice.
The whole "smart tanker" concept gradually faded into the background, though it's hard to say it has gone away. The idea of using the 767 as a surveillance platform, initially designated the "Multi-Sensor Command & Control Aircraft (MC2A)", remained in the foreground. A Boeing 707 jetliner, configured as an experimental "MC2A-X" prototype of the production MC2A, performed its first flight on 18 April 2002. The machine was given the name "Paul Revere" to reflect its mission to provide warning of attack.
In the summer of 2003, the Air Force awarded a contract to Boeing for a test-bed aircraft, based on the Boeing 767-400ER airliner. The production MC2A was to be designated the "E-10A". The original plan was to begin with the battlefield surveillance mission; then add an AEW capability to the E-10A, allowing it to replace the E-3 AWACS; and then add SIGINT capabilities, allowing it to replace the RC-135 Rivet Joint platform. Critics suggested that trying to have one aircraft do all three functions was flying in the face of the laws of physics, and the Air Force then considered separate "E-10B" AEW and "E-10C" SIGINT versions.
Although defense programs tend to be moving targets during their development, it was not surprising that the E-10A MC2A suffered some political difficulties because Congress found the Air Force's story on the machine exasperatingly fuzzy and inconsistent. Congressmen weren't the only ones baffled; AVIATION WEEK magazine summed up the exasperation in a short article titled "One Plane To Confuse Them All" -- no doubt the author was a Tolkien fan.
Other political difficulties were catching up with the program as well. It was about at this time that the program's linkage to the 767 tanker effort led to difficulties. The Air Force and Boeing came up with an unconventional funding scheme for the tankers based on a lease arrangement. The lease deal attracted some very negative attention from the US Congress, with critics claiming it amounted to a corrupt pay-off program for Boeing at taxpayers's expense.
The Air Force defended the scheme, saying the numbers added up over the long run, but unfortunately there had been a series of corporate scandals, some of them unbelievably corrupt, at American corporations over in the previous few years, and the public and the politicians were highly sensitive to such matters. An Air Force civilian official who had been working in part on the tanker deal arranged a high-paying job with Boeing for herself while she was setting up the deal, which was blatantly illegal and ended up putting her behind bars in Federal prison; Boeing CEO Phil Condit had to step down. The Air Force insisted that the tanker deal had been reviewed to ensure that it was clean and that the service desperately needed the new tankers, but Congress killed the deal anyway.
The E-10 MC2A effort was caught in the shadow of the fiasco, and its shifting definition didn't inspire confidence in the project in Congress, particularly at a time when the US armed services were heavily committed in the Middle East and money was tight. The E-10 was cut from the Fiscal Year 2008 budget.
It's an ill wind that blows nobody good, and the E-8C Joint-STARS was one of the clear beneficiaries, with plans to fit MP-RTIP rising back up the priority queue and the reengining effort finally getting off the ground. However, the Air Force still has future requirements to deal with. It is very possible that a bizjet platform will be seen as the way of the future, though for the moment the Air Force is in recovery on the E-10A program and no new plans have been offered.
* The US military has not abandoned the idea of using a mid-sized bizjet platform for surveillance and other roles. As mentioned, the Army's Aerial Common Sensor platform originally planned to use the EMBRAER ERJ-145, and it seems plausible that the USAF may acquire a cheaper platform as a complement to or even a substitute for the MC2A.
Bizjet-based "special mission" aircraft are already in operational service, and are clearly headed for increased use. The Gulfstream series of business jets is a prominent player in this trend, due to its value, capability, and widespread use with military forces all over the world.
* The Gulfstream has been in use for military special missions for decades. In 1979, the Danish government ordered three of the early "Gulfstream III" business jets for fisheries patrol, fitting them with sea search radar in a modified nose and improved navigation and communications gear. Except for the custom gear, the Danish Gulfstream IIIs were configured as cargo-transport aircraft and are sometimes used in that role.
However, in 1984 Grumman introduced the "SRA-1", a modified Gulfstream III intended to advertise the type's adaptability to more warlike roles. The SRA-1 featured a mockup of a Motorola "Side-Looking Airborne Multimode Radar (SLAMMR)" system in a pod under the fuselage; three dummy stores pylons under each wing, for a total of six; and small dummy pods on the wingtips for an "electronic support measures (ESM / emitter targeting)" or other EW system. The SRA-1 also featured a new, large cargo door, apparently not only to support getting large pieces of electronics gear in and out, but to give the aircraft a secondary cargolifter role.
The SRA-1 was displayed at the Farnborough Air Show in the UK in September 1984, with the dummy stores pylons fitted with dummy stores such as torpedoes, missiles, and bombs. One of the few pieces of real gear that the SRA-1 carried was a "Long Range Optical (LOROP)" camera for photographic reconnaissance. Grumman proposed a wide range of possible configurations to potential buyers, and used the demonstrator to try out plausible kit such as countermeasures gear, including warning receivers and chaff-flare dispensers; a dummy inflight refueling probe; and even tanker operation using an external refueling pod. Nobody bit on the armament or other exotic options, but the Indian Air Force did buy two Gulfstream IIIs for special missions, with the aircraft delivered in 1986. The exact configuration and use of these two aircraft remains mysterious, but they appear to be fitted with LOROP cameras and may have had some ELINT gear.
* The improved "Gulfstream IV" was introduced in 1985, and Grumman promoted an "SRA-4" special mission configuration for the type. This led to a 1992 purchase by Sweden of two Gulfstream IVs configured as SIGINT platforms, with a canoe fairing under the nose. These two aircraft were given the designation of "S-102B Korpen (Raven)".
The "Raven" name for the S-102B does reflect the common nickname for EW crews as "crows" or "ravens", but it has special significance in Sweden, since in Norse mythology ravens were the eyes and ears of the uber-god Odin. He would send his two ravens, "Hugin" and "Munin", to the corners of the Earth, and they would return and whisper what they had seen in his ears. Of course, the two S-102Bs were given the names of Odin's ravens.
* The Gulfstream V has continued in this tradition of small-scale Gulfstream sales for special missions. Two were sold to the Japanese Self-Defense Forces in November 2001 as "Sea Watch" coastal patrol / search and rescue aircraft. They were fitted out by Fokker Systems of the Netherlands with a Thales search radar in a neat canoe fairing in the belly forward of the wing, as well as a FLIR imager. Japanese radios will be installed by Murabeni, Gulfstream's Japanese agent and prime contractor for the project, when the aircraft are delivered to Japan. They have two mission consoles, one for the sensor systems operator and the other for the communications system operator; they retain 19 airliner-type seats for use as personnel transports, and have a medevac litter and a galley in the rear cabin. The aft baggage door can be opened in flight to drop a liferaft. A third aircraft, to be based on the more capable G550 platform, is in discussion.
In December 2001, Israeli announced the purchase of three Gulfstream Vs as special "electronic mission" platforms. This contract evolved to specify purchase of four G550 machines, with options for two more. They will be operated by the Israeli Air Force (IAF) under the name of "Nachson (Pioneer)", with some of the batch in a "compact AEW (CAEW)" configuration and some in a SIGINT configuration.
Although the Israelis are notoriously security-conscious, the IAF has actually displayed detailed models of the Nachson configurations. The CAEW configuration is fitted with an Elta EL/I-3001 Phalcon phased-array radar, with antenna fairings on nose and tail and alongside the fuselage. There is also an extensive farm of blade antennas on the top and bottom of the fuselage, presumably for communications gear but possibly also for some complementary ELINT functions.
The SIGINT configuration has a litter of blade antennas on top of the fuselage and under the wings, plus a large fairing under the fuselage that suggests a SAR antenna. Sources hint that three of the G550s will be fitted out to the CAEW configuration, while the fourth will be fitted out to the SIGINT configuration.
The Israelis developed a testbed for a surveillance platform using a Boeing 737. It includes an IAI-Elta-built SAR, electro-optic sensors, wideband datalinks, and possibly SIGINT gear. It was used in early 2002 to track the progress of a freighter, the KARINE-A, which was carrying weapons for Palestinian militants.
* General Dynamics has developed their own concepts for a Gulfstream V EW variant, designated the "EC-37 Special Missions Aircraft (SMA)" and clearly a descendant of the SRA-1.
The EC-37 concept envisions an aircraft with accommodations for 12 to 15
battle staff and EW operators, with payloads stowed in blisters or attached
to underwing pylons. General Dynamics believes they could sell an EC-37 for
$100 million USD.
GULFSTREAM V BIZJET (GENERAL DYNAMICS EC-37 BASELINE AIRCRAFT):
_____________________ _________________ _______________________
spec metric english
_____________________ _________________ _______________________
wingspan 28.5 meters 93 feet 6 inches
wing area 105.63 sq_meters 1,137 sq_feet
length 29.4 meters 96 feet 5 inches
height 7.87 meters 25 feet 10 inches
empty weight 24,200 kilograms 53,350 pounds
max loaded weight 40,370 kilograms 89,000 pounds
maximum cruise speed 925 KPH 575 MPH / 500 KT
take-off length 1,790 meters 5,870 feet
service ceiling 15,500 meters 51,000 feet
range 12,050 kilometers 7,475 MI / 6,500 NMI
_____________________ _________________ _______________________
The Gulfstream V is powered by two BMW Rolls-Royce BR710 turbofans with a
thrust of 65.6 kN (6,690 kgp / 14,750 lbf) each.
An illustration of the EC-37 displaying a "notional configuration" shows it
with a pod mounted on top of the tail to house a wideband satellite data
communications link; a canoe fairing under the forward fuselage for SIGINT
gear to perform eavesdropping and direction finding; and six detachable pods
carried under the wings, including:
While this is likely a more diverse payload than would be carried on typical operational missions, the idea of carrying SIGINT and jammer gear on the same flight is practical. Using fast digital control systems, the jammer systems are switched off for a few milliseconds, allowing the SIGINT gear to spot a target, and then the jammer systems are turned back on to electronically attack the new target. The technique is called "looking through".
General Dynamics is also investigating integration of an AESA-based multipurpose EW system, either built into the fuselage or into the 1.8 meter (6 foot) tall winglets at the tips of the Gulfstream V's wings. They also suggest that the EC-37 SMA could be used as an auxiliary GPS signal source to help defeat GPS jamming and enhance GPS target location.
General Dynamics says the EC-37 SMA has plenty of engine power and can easily operate at altitudes high enough to give its payload suite a clear view of a battle theater. In a typical mission profile, the aircraft could reach operating altitude in 25 minutes, fly 1,600 kilometers (1,000 miles), and remain on station for 10 hours at 14.3 kilometers (47,000 feet), without mid-air refueling.
The EC-37 SMA would offer a shirtsleeve environment for its crewmembers. Advocates also point out that the tail-mounted turbofans of the Gulfstream V do not block the view of underwing electronics pods, as would be the case for an EW platform based on the Boeing 737 or Airbus jetliners, which have turbofans mounted under the wings. Critics suggest that the Gulfstream V is too small an aircraft to mount antenna arrays or carry gear with really adequate capability.
The EC-37 SMA notional configuration does not include armament, but the Navy is also interested in an aircraft with the capability to carry the Harpoon antiship missile, the similar SLAM land-attack cruise missile, or other long-range precision strike munitions, allowing the EW aircraft to not only identify and locate targets, but to attack and destroy them as well.
* In the summer of 2003, Gulfstream began to promote an interesting variation on the Gulfstream V special mission concept, in the form of a Gulfstream G550 configured as a UAV. Stripped of all the niceties required for carrying people, it would have a load capacity of 9,525 kilograms (21,000 pounds).
The "GV-UAV" concept, to give it a name, was pitched as a solution for the US Navy's need for a replacement for the current EP-3 Aries SIGINT aircraft, as well as the Navy BAMS requirement. It could also be used as a tanker, either with dedicated refueling gear or fitted with buddy refueling packs on its stores pylons. For the moment, the GV-UAV remains a highly speculative concept.
* Although the Grumman Gulfstream has likely the highest profile as a platform for bizjet-based special missions aircraft, of course there are plenty of similar aircraft that can do the job as well.
In 1996, the South Korean government awarded a contract to Raytheon for four
Raytheon Hawker 800XP (Extended Performance) bizjets configured for the
surveillance role, with four (some sources say six) more obtained later.
Initial deliveries were in late 1997. The Raytheon Hawker 800XP is of
conventional bizjet layout, with a swept low-mounted wing and twin turbofans
at the rear. It is less than half the size of a Gulfstream V, and is
normally sold as an 8 to 12 seat executive jet.
RAYTHEON HAWKER 800XP (BASELINE AIRCRAFT):
_____________________ _________________ _______________________
spec metric english
_____________________ _________________ _______________________
wingspan 15.67 meters 51 feet 5 inches
wing area 34.75 sq_meters 373.85 sq_feet
length 15.58 meters 51 feet 1 inch
height 5.3 meters 17 feet 5 inches
max takeoff weight 12,700 kilograms 28,000 pounds
max payload weight 5,440 kilograms 12,000 pounds
max cruise speed 860 KPH 535 MPH / 465 KT
service ceiling 12,500 meters 41,000 feet
range 4,850 kilometers 3,000 MI / 2,615 NMI
_____________________ _________________ _______________________
The Hawker 800XP is powered by twin AlliedSignal TFE731-5BR turbofans
providing 20.7 kN (2,115 kgp / 4,660 lbf) thrust each.
The South Korean Hawker 800XPs have been delivered in at least two
configurations, with visibly different sets of antenna fairings. Sources
give confusing data on them, and it appears that one variant is focused on
the SIGINT mission, while the other carries a SAR-MTI system and possibly
other sensors. They have high-speed datalinks to transfer data to associated
ground systems, also provided in the Raytheon contract. The name "Peace
Krypton" has been used in connection with these machines, but it is unclear
if it applies to one or both variants.
* The EMBRAER company of Brazil is now offering a set of special mission
aircraft based on their EMBRAER Regional Jet 145 (ERJ-145) regional jetliner.
The ERJ-145 is twin-turbofan aircraft with a configuration generally similar
to that of the Global Express or Gulfstream V, and has a passenger capacity
of 50 seats. It is a thoroughly modern aircraft with a state-of-the-art
glass cockpit. EMBRAER announced development of the type in 1989, though due
to various problems first flight wasn't until 1995. Initial deliveries were
in 1996.
EMBRAER ERJ-145 (RB-99B BASELINE AIRCRAFT):
_____________________ _________________ _______________________
spec metric english
_____________________ _________________ _______________________
wingspan 20.04 meters 65 feet 8 inches
wing area 51.18 sq_meters 550.91 sq_feet
length 29.87 meters 98 feet
height 6.75 meters 22 feet 2 inches
empty weight 11,150 kilograms 24,585 pounds
loaded weight 20,600 kilograms 45,425 pounds
cruise speed 833 KPH 520 MPH / 450 KT
service ceiling 11,275 meters 37,000 feet
range 2,450 kilometers 1,520 MI / 1,320 NMI
_____________________ _________________ _______________________
The ERJ-145 is powered by twin Allison AE-3007A turbofans with 31.3 kN
(3,190 kgp / 7,040 lbf) thrust each. Data is for the standard ERJ-145,
though there is a slightly heavier "long-range" variant.
The Brazilian Air Force found the ERJ-145 to be an attractive electronics
platform, and obtained five "R-99A" AEW variants fitted with Swedish Ericsson
Erieye AEW radar, referred to as the "ERJ-145SA (Surveillance of Air)" by
EMBRAER. The R-99A features a long AESA antenna carried on the back of the
aircraft, with the antenna consisting of 192 transmit-receive modules. The
Erieye is capable of tracking hundreds of targets at once at a maximum radius
of about 460 kilometers (286 miles), and can deal with both airborne and
water-borne targets, using four different waveform modes. It is capable of
wide-area search or close examination of targets with a high-power narrow
beam. The R-99A carries a suite of SIGINT gear as well.
EMBRAER is also selling an "R-99C" maritime patrol version of the ERJ-145, which has been ordered by Mexico, and built three "R-99B" surveillance variants for the Brazilian Air Force, referred to as the "ERJ-145RS (Remote Sensing)" by EMBRAER. The prototype R-99B was rolled out in 1999, with initial aircraft delivery in 2001 and final delivery in the spring of 2002. The primary sensor of the R-99B is the Canadian-built MacDonald-Dettwiler "IRIS (Integrated Radar Imaging System)" SAR with three-dimensional imaging capabilities, with the antenna installed in a fairing under the belly; a Daedelus multispectral scanner; a "Skyball" EO/IR turret, and the same SIGINT suite as used on the R-99A.
The IRIS SAR can operate in an L-band polarized mode that provides some foliage penetration, or an interferometric X-band mode that can create 3D maps. It has a slant range of about 120 kilometers (65 NMI) at normal operating altitude. The SAR has a wide-area mode, multiple strip and spot modes, and MTI and air-to-air modes. In strip modes, the strips can have swath widths of 20 to 120 kilometers (12.5 to 75 miles), with a tradeoff with resolution, which can be 3, 6, or 18 meters (10, 20, or 60 feet). Spot modes can give a resolution of 1.8 meters (6 feet).
The multispectral scanner has 31 channels, including 28 visible and near-infrared channels, including one realtime color imagery channel; two short-wave infrared channels; and a thermal infrared channel. The EO/IR system includes three cameras, including an infrared camera with a 21 magnification zoom, a color camera with an 18-power zoom, and a high-resolution color spotter scope. The SIGINT system used on both the R-99A and R-99B includes a wideband COMINT system with communications intercept capability, direction finding, audio recording, and a panoramic operator display; and a wideband ELINT system with direction-finding and a panoramic operator display.
Although AEW aircraft are not discussed in this document, the R-99A and R-99B have to be discussed together because they are principal and complementary elements of Brazil's System for Vigilance of the Amazon (SIVAM)" program, run by the Brazilian Air Force. SIVAM is an extremely interesting application for surveillance aircraft and is worth discussing in detail.
Brazilian authorities have an immense problem in monitoring activities in the huge Amazon region, which covers about 5.2 million square kilometers (2 million square miles), about the size of the US to the west of the Mississippi River. They believe with good reason that much of what is going on there unknown to the authorities isn't good -- illegal logging and mining, smuggling, drug manufacture, and insurgent training and support. The SIVAM network integrates ground stations, air platforms, and satellite data linked through an extensive communications network to ground centers to observe what is going on in the jungle region. Incidentally, satellite data is now being provided by the "China Brazil Earth Resource Satellite (CBERS)" series of spacecraft, which as the designation states are being developed in collaboration with China, and are launched by Chinese boosters.
Although the R-99s aren't actually performing a "battlefield surveillance" mission in the strict technical sense, the distinction is mostly semantic. The R-99A monitors air and water traffic, while the R-99B observes what is going on down on the ground, with both platforms performing SIGINT operations to observe what's going on over the airwaves. The systems of the two types of machines were built so they could operate simultaneously without interfering with each other, while they stay on station for six-hour shifts. The RB-99B's SAR system is particularly useful, since the Amazon is very rainy much of the year, and many illegal activities are carried out during the rainy season when they are harder to detect.
If the aircraft spot targets that need to be dealt with, such as clandestine jungle airstrips, they can call on paramilitary forces and EMBRAER Super Tucano light strike aircraft to take them out. SIVAM is directed from a large "campus" at Manaus, in the heart of the Amazon region; surveillance data from the aircraft, ground SIGINT stations, and CBERS satellites are analyzed and integrated at this site, and used to plan responses. The R-99s have proven so effective that drug dealers have assigned "eyes" to keep track of their comings and goings at Anapolis AFB, near Brasilia. The eyes report in with cellphones, which are ironically often picked up by the SIGINT gear on board the aircraft. SIVAM elements like the R-99A and R-99B have been involved in cooperative operations with Brazil's neighbors, such as locating bases set up by Peruvian Shining Path guerrillas.
The R-99B also performs resource mapping and pollution monitoring, and can help in fire-fighting by locating infrared "hot spots" on the ground through the smoke. These sorts of tasks are often used in support of the "System for the Protection of the Amazon (SIPAM)", a civilian-run organization that complements SIVAM. SIPAM is referred to as a "green" organization, with an environmental focus, while SIVAM is a "blue" organization, with an air power / intelligence focus. The R-99s have been receiving upgrades, such as AE 3007 A1P engines with 20% more thrust and thrust reversers, as well as system upgrades to improve their effectiveness.
EMBRAER sees their ERJ-145 AEW and surveillance platforms to be highly competitive on the world market. Greece has obtained the R-99A and as mentioned, Mexico has obtained the R-99C. Having the ERJ-145 selected for the US Army ACS program, mentioned in a previous chapter, was a big win since the US military is strongly inclined to "Buy American", and the cancellation of the program must have been a great disappointment.
* I got into the subject of battlefield surveillance aircraft by a somewhat indirect route. They're something of a hot topic in aerospace at present, and I took some notes from articles on the subject. Over time, I became increasingly interested in the entire range of airborne electronics platforms, such as battlefield surveillance, AEW, SIGINT, antisubmarine warfare (ASW), and jammer platforms, and started to accumulate more information on them. I finally obtained enough information to start piecing together bigger pictures.
The chapter on the RC-7 was originally released as a stand-alone document in July 1998, and the chapter on the Grumman Mohawk was similarly released as a stand-alone document in February 2001. A month later I was acquiring notes on Joint-STARS and realized I had enough to nail down battlefield surveillance aircraft, and I took everything I had on the subject and rolled it into this document.
Incidentally, I was taken to task after releasing the first version of this document for not discussing helicopter-based battlefield surveillance platforms. However, the focus of this document is on fixed-wing aircraft and I think it best to discuss rotorcraft in a separate document.
* I have actually never seen any of the aircraft described in this document except for the Grumman Mohawk. I have a clear memory of seeing one minus its wings parked at Fort Gordon, Georgia, in the winter of 1972:73. I have less clear memories of seeing Oregon National Guard Mohawks flying around while I was a student at Oregon State University in Corvallis, Oregon, in the late 1970s.
I had a little fun with the initial release of the RC-7 document. The week after the crash of the RC-7 in Colombia, an assistant newspaper editor emailed me and asked if he could interview me about the aircraft. I politely replied that the suggestion was very flattering, but an interview would not prove useful to him, since once he read the document he knew as much about the subject as I did. He thanked me kindly and went about his business. Later in the day, however, he sent me another message. He'd contacted the Pentagon on the matter as well, and as background information they faxed him a printout of this document. Nice of him to tell me that.
* Sources include:
Other materials were also found on the Federation of American Scientists website and US military sources found on the web.
* Revision history:
v1.0 / 01 apr 01 / gvg
v1.1.0 / 01 apr 02 / gvg / General cleanup & improvements.
v1.1.1 / 01 jun 02 / gvg / Added comments on MC2A & "Paul Revere".
v1.2.0 / 01 jul 04 / gvg / General enhancement.
v1.2.1 / 01 sep 04 / gvg / Added comments on ERJ-145 ACS, SIVAM.
v1.2.2 / 01 sep 06 / gvg / Reset on ACS, general cleanup.
v1.2.3 / 01 may 07 / gvg / Reset on E-10A.
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