Jackson Flores jr/SAO JOSE DOS CAMPOS
The addition of the EMB-145 surveillance platform and the ALX light strike aircraft will give the Brazilian air force new teeth to police the Amazon, particularly against drug smugglers.
Sparsely populated and little explored, the Amazon Basin encompasses 5.2 million square kilometres of nearly impenetrable rain forest and scrubland that fan across 61% of Brazilian territory. With 35% of the planet's rain forests and immensely rich mineral deposits, the region has resources yet to be gauged fully.
Controlling and monitoring its fringes that extend to seven neighbouring countries along an 11,000km (6,800 miles) border, is almost impossible - given Brazil's limited resources.
As a result, illegal activities within the Amazon Basin have increased at an alarming pace. Natural resources have been squandered or plundered. Smuggling in the region has grown dramatically.
This led to the creation in 1990 of the Sistema de Protejo da Amazonia (SIPAM), or Amazon Protection System. The new joint civil/military agency links the governmental bodies that autonomously oversaw the Amazon's controlled development, enforced existing environmental laws and performed surveys.
Amazon vigilance
To provide it with tools and information, SIPAM will count on the Sistema de Vigilancia da Amazonia (SIVAM), or Amazon Surveillance System, a network of fixed and mobile ground radar stations, remote monitoring devices, satellite-based sensors and airborne surveillance aircraft. Data collected by these and other sensoring systems will be fed to three regional surveillance centres at Manaus, Belm and Porto Velho that will report to the General Co-ordination Centre in Brasilia.
During SIVAM's initial development, the air segment was identified as key to the entire system. With scant radar coverage over the Amazon region, effective air traffic control was virtually impossible outside major airport terminal areas. This shortcoming also encouraged the increase of illegal flights. Indeed, the Brazilian air force ascertained that 2,300-2,500 illegal flights were performed daily within the region. Many involved local landowners making brief hops without filing a flightplan, but a worrying number was directly linked to smugglers transporting gems, precious metals or drugs from and to clandestine airstrips.
Consequently, SIVAM requirements called not only for an airborne early warning and control (AEW&C) platform, but also for an aircraft capable of performing such missions as photomapping, border surveillance, electronic intelligence (ELINT) and communications intelligence (COMINT), airspace management, and search and rescue co-ordination.
Discarding foreign options as economically or politically impractical, the Brazilian Government turned to Embraer to develop a domestic solution.
Work began in 1994 by mating the Ericsson PS-890 Erieye radar and other sensors to the EMB-120 Brasilia airframe. Conflicting mission requirements immediately precluded the development of a single aircraft to perform the various tasks dictated by the SIVAM. Embraer initially concentrated on developing two distinct versions of the EMB-120. But the dual tasks of squeezing the necessary mission sensors into the respective airframes, along with additional fuel tanks, were hard to reconcile. To satisfy SIVAM requirements, both EMB-120 versions needed extensive modification such as fuselage stretching, uprated powerplants and strengthened landing gear. Although preliminary design work continued for some time, the Brasilia was found wanting. Embraer then cast its eye toward a more attractive alternative then leaving the company's drawing boards: the ERJ-145 regional jet.
For the SIVAM, a suitably modified ERJ-145 offered advantages that surpassed any benefit in continuing to develop the Brasilia. Although some structural and systems changes would be needed, these would be far less extensive than those envisaged for the EMB-120.
Aside from the performance gain afforded by a jet-powered aircraft, the more spacious ERJ-145 main cabin allowed installation of all required mission systems destined for the AEW&C and remote sensing aircraft, while allowing considerable systems growth. Consequently, with the long range ERJ-145LR as a start, Embraer initiated preliminary design and development work on the two aircraft that later became known as the EMB-145SA and EMB-145RS. As Embraer refined its studies, the SIVAM co-ordinating committee agreed to the platform change. In March 1997 the Brazilian Government and Embraer signed a $1.3 billion contract for five EMB-145SAs and three EMB-145RSs.
Adhering to US Federal Aviation Regulation Part 25 certification rules, structural modifications to the proposed airframes are restricted primarily to the fuselage, so that the EMB-145SA can bear the 1,300kg (2,900lb) load of the Erieye radar assembly that straddles the central fuselage. Structural frames have been strengthened and several window panels removed. Modifications to the remote sensing aircraft, the EMB-145RS, included altering the forward and central fuselage module to receive a belly-mounted synthetic aperture radar (SAR) and a forward looking infrared (FLIR). To improve directional stability, ventral strakes are fitted on the rear fuselage of both aircraft.
More powerful generators are installed, and the entire electrical system is modified to supply the increased power demands of the mission equipment. Similarly, the environmental control system is upgraded and the auxiliary power unit replaced. Needing to increase range substantially, Embraer has installed additional fuel cells in the aft fuselage, which also required changes to the fuel system. Fuel jettison capability has been added.
These and other changes have increased the ERJ-145LR's 22,000kg maximum take-off weight (MTOW). Consequently, Embraer has modified the landing gear, improving brakes, tyres and wheels. Since weight increases degrade performance, Embraer has replaced the two AE3007A turbofans with higher-rated AE3007A1Ps to maintain ERJ-145LR handling and performance.
Ericsson's Erieye active phased-array pulse-Doppler radar is the ERJ-145SA's primary sensor. Providing 360í coverage, the Erieye is capable of scanning two lateral sectors, with a 350km (190nm) detection range against low-flying aircraft. Equipped with datalink, other ERJ-145SA mission sensors and equipment include identification friend or foe/secondary surveillance radar and comprehensive electronic support measures and COMINT suites.
The Erieye's high degree of automation reduces operator workload, which determines the number of mission crewmembers. The three forward-facing stations are arranged to either side of the aircraft's operation compartment. The mission crew comprises a tactical control officer, as well as electronic warfare and intercept operators. There is provision for a fourth console. The forward fuselage compartment can seat five reserve crewmembers.
With an interior arrangement similar to its AEW&C counterpart, the EMB-145RS' primary sensor is a McDonald-Dettwiller SAR. Capable of strip mapping a swath up to 100km wide, the SAR can monitor road and river traffic, detect construction of clandestine airfields and the opening of clearings that can harbour illegal activity. The EMB-145RS is also endowed with a multispectral scanner and FLIR Systems Star Safire FLIR, plus ELINT and COMINT suites to intercept, identify and locate microwave and communications emissions associated with illicit operations.
Tucano with fangs
The ALX's history, meanwhile, can be traced to 1988, when the Brazilian air force and Embraer decided to research the EMB-312 Tucano's potential for more than advanced training. Conducted with an EMB-312 and Shorts development prototype for the Royal Air Force Tucano T1, the investigation was oriented toward counter-helicopter operations and interception of general aviation aircraft. The latter was important because of difficulties encountered in intercepting and establishing a gun or missile firing solution against a slow-flying target with Brazilian air force fighters such as the Dassault Mirage IIIEBR and Northrop F-5E. Promising results from the trials encouraged Embraer to develop an EMB-312 with a higher rated powerplant. The findings were further validated by the Peruvian air force's success over the years in bringing down 65-70 drug-smuggling aircraft with its EMB-312s.
Initially designated the EMB-312F, and later the EMB-312H, feasibility studies gained momentum during the US Air Force and Navy Joint Primary Aircraft Training System (JPATS) competition. Since the JPATS performance and technical requirements established by the JPATS closely matched those for the EMB-312H, work on the new Tucano was accelerated. A standard EMB-312 was modified as a proof-of-concept aircraft, and first flew in September 1991. Quickly renamed the Super Tucano, development was directed towards Embraer's participation in JPATS, although development data were passed to the EMB-312H design team.
Despite the Brazilian air force's pressing need for a border surveillance aircraft capable of performing light strike duties in conjunction with SIVAM, another of the service's requirements would also be met by the armed version of the Super Tucano. The near-term need to replace the EMB-326GB Xavante as a weapons trainer was equally urgent. As the ALX, and designated the EMB-314, design and development of the light strike version of the Super Tucano began in 1993. In August 1995, the Brazilian air force ordered 50 single-seat and 50 two-seat ALX.
Powering the ALX is a 930kW (1,250shp)-rated Pratt & Whitney Canada PT6A-68/1, driving a Hartzell five-bladed propeller. The ALX has a longer fuselage that its trainer forebear, with a larger, reprofiled, laterally hinged canopy. Embraer has discarded the original Tucano wing, endowing the ALX with a wing that employs the NACA 63-415 aerofoil at the root and which moves to the NACA 63A-212 at the tips. A larger tail has two ventral strakes for improved directional stability.
The ALX will operate in a hot and humid environment. Its frequent deployments to dirt strips for weeks at a time require a rugged structure and systems. Stressed for loads of +7g to -3.5g, the ALX has a 3,150kg zero fuel weight and 3,600kg MTOW. Since its first flight, trials have shown that it can reach 300kt (555km/h) in clean configuration and 245kt with external stores on four wing hardpoints and a single ventral station. With a maximum service ceiling of 35,000ft (10,600m), the aircraft has a range of 750km in a clean condition at a cruise altitude of 10,000ft, falling off to 540km fully armed.
The ALX has many design features in common with its EMB-312 relatives, but inside the cockpit, any similarity ends. Flight information is provided on two night-vision goggle compatible 150 x 200mm electronic flight information system multifunction displays (MFDs). The controls are configured for hands-on throttle and stick operation. At the heart of the aircraft's mission system is two Elbit-developed mission and display processors (MDPs) that are linked to the ALX's head-up display and MFDs.
Acting as the 1553B databus controller, the MDP receives and processes data from the aircraft's sensors and performs tasks that include navigation/attack calculations. The ALX is also equipped with an engine indication and crew alerting system, an embedded global positioning/inertial navigation systems and radar altimeter, data recorder, Mode S transponder, distance monitoring equipment, VHF omnidirectional ranging, instrument landing system, emergency locator transmitter, dual airborne direction finders and a dual VHF communications system. Both versions have Martin Baker BR10LCX ejection seats.
Designated by the Brazilian air force as the A-29 (single-seat) and AT-29 (two-seat), the ALX packs a hefty punch. The aircraft's five hardpoints are cleared for up to 225kg loads, and the ventral and inboard stations are configured as wet points. A wide range of weapons can be carried, from Mk81 and Mk82 low-drag general purpose bombs to Mectron's MAA-1 Piranha short range, infrared guided, air-to-air missiles. When equipped with a laser designator, it can deliver laser-guided munitions.
Finally, two 12mm machine guns with 200 rounds each are installed in the wing. Another gun, the GIAT NC621 20mm cannon, can be carried on the ventral station. The ALX's sensor package relies principally upon a ventrally mounted Safire FLIR. The aircraft also has a radar warning receiver, missile approach warning system and a chaff/flare dispenser.
Into Service
The first EMB-145SA - designated by the Brazilian air force as the R-99A - will undergo flight trials and be fitted with mission sensors before being sent to the 2/6 Grupo de Aviçao, an Anpolis-based squadron activated in January to operate the surveillance aircraft. With roll-out scheduled for November, the first R-99B - as the EMB-145RS has been designated - will follow a similar flight test and fitting-out schedule. Delivery of the SIVAM's final EMB-145SA/RS is slated for May 2002.
It is likely that the air force's first 30-40A-29/AT-29s will go to Natal, on the north-east coast of Brazil, to replace Xavantes in service with 2/5 Grupo. It is in the Amazon Basin that the aircraft fulfil their true role. They will probably replace AT-27 Tucanos of 1/3 Grupo at Boa Vista and 2/3 Grup-o at Porto Velho in the border surveillance role.
Source: Flight International
