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Saab 340 AEWC

sweden flag Sweden (1997)
 Airborne Early Warning & Control (AEWC) Aircraft- 12 Built

The Saab 340B AEW&C and the Saab 2000 AEW&C are airborne early warning and control (AEW&C) airplanes that were developed from the basic Saab 340B airplane, a twin-engine turboprop regional airliner developed and built in partnership with the now defunct American aircraft manufacturer Fairchild Aircraft .  The model was named “Metro III” when manufactured by Fairchild Aircraft. The Saab 2000 AEW&C is based upon the Saab 2000 airliner,it being a variant of the basic Saab 340B model. These airborne radar models came from the inventiveness of the Flygvapnet, as the idea of fitting the basic transport model already in service emerged considering the gaps the Flygvapnet had regarding the type of air asset. This paid off as the Nordic nation is now equipped with an airborne and air control (flying) system that provides a very valuable tool for the Flygvapnet to monitor the Swedish skies and even abroad, as the post-Cold War era meant new missions beyond national defence for the Swedish Armed Forces in general. The basic 340B  version was, despite its initial non-military use, a display of technological advancement with advanced avionics and a product of the company’s desire to revive its interests in the civil market after the not entirely successful Saab Scandia 90, in the 50’s.

The Saab 340B AEW&C (Saab 340B) is a twin-engine turboprop medium size airliner, capable of carrying more than 30 passengers and with a conventional design, mainly for short-range regional flights. The main airframe is cylindrical, with the wings placed near the middle section of the airplane and of trapezoid and thin configuration. The nose is not rounded being rather sloped downwards, and the wings and horizontal control surfaces being angled upwards. The engines are not beneath the wings, as the configuration is that of a low-wing airplane; instead, they are placed above the wings and logically enrooted in them. The Saab 2000 differs from the basic model in the sense that it is larger, wider, slightly taller and with more wing area.

The Saab 340B AEW&C is powered by two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller each, allowing the airplane to reach a cruise speed of 522 km/h (325 mph). The Saab 2000 AEW&C also has a different powerplant, being 2 Allison/Rolls Royce AE 2100A turboprop engines of 4,591 hp with a Dwoty Rotol six-bladed constant speed propellers each, having improved performance than the 340B version: for instance, the cruise speed it can reach is up to 629,68 km/h (391,26 mph).

Given the role of the airframes, both are fitted with an Ericsson Erieye (PS-890) radar installed above the main airframe, with a range of S-band, 3 GHz (GigaHertz) with a range of 160 degrees on each side. The radar is a rectangular pod, in contrast with the radars one would see on more classical AEW&C planes (for example the Boeing E-3 Sentry or the Ilyushin A-50). The radar has a range of 300-400 km capable of detecting sea and airborne targets.

History

The A 340B AEW&C (S 100B Argus) came to be with the idea of having a Swedish modified AEW&C asset and an alternative to the comparatively more expensive Boeing E-3 AWACS. The Flygvapnet was already operating with a Saab 340B for VIP transport, designated TP 100A, and that same airframe was to be the basis for the new airborne defence and air control radar. By the mid-90s, the first unit entered in service with the Flygvapnet. A total of six airframes were ordered: four with the radar already installed and two without the radar, prepared to have it installed when needed and serving as VIP transports during peacetime. As mentioned above, the Saab 340B AEW&C (S 100B Argus) is based upon the commercial airliner Saab 340B, which is a good platform given its structural characteristics, avionics, and performance. This airframe began its development in the 70s, with the propulsion system that it has being chosen as it was more economic than the jet propulsion system back then. It is reported that cost/efficiency considerations and the effects of the 1973 Oil Crisis made the company to pick the turboprop propulsion system. The US Airline Deregulation Act of 1978 gave further impulse for the basic model to be developed. This airplane was developed and built jointly with Fairchild Aircraft, mainly due to the fact that Saab thought the production capacity would not be enough. As a result, from 1980 to 1987, Fairchild was tasked with manufacturing the wings, the tail, and the engine nacelles. Saab, in turn, was tasked with manufacturing the main airframe, covering the 75% of development costs and the system integration and certification. The first Saab 340 flew in 1983, with the first airplane serving with an airline in 1984. After Fairchild ceased operations, Saab began to fully manufacture the Saab 340, doing so until 1999. The Saab 2000 came to be due to a decision in 1988 by Saab to develop an elongated version of the Saab 340 capable of carrying up to 50 passengers, having the same economic efficiency along with better climbing performance. Its first flight was in 1992, entering into service in 1994.

Currently, the S 340B AEW&C (S 100B Argus) operates in the Flygvapnet with 4 units sporting radar equipment and two additional units serving as VIP transports, ready to have the radars installed when needed. Its production was also finished in 1999, with 12 AEW&C units built: six for the Flygvapnet, 2 for the Royal Thai Air Force and 2 for the Pakistan Air Force, with 2 more under production for the United Arab Emirates Air Force. 2 modified airframes were loaned for the Hellenic Air Force from 2000 to 2003, while Greece received two Embraer RJ-145 AEW&C aircrafts fitted with the same Ericsson Erieye radars. It is noteworthy to state that of the basic airliner version, 460 units were built. Of the Saab 2000 airliner version, 63 were built; in turn, the Saab 2000 AEW&C version was introduced in 2010 for the Pakistan Air Force, with 8 units built so far and operating with the Pakistan Air Force, the Royal Saudi Air Force and the United Arab Emirates Air Force. Three more units would be delivered for the Pakistani Air Force.

Design

The Saab 340B AEW&C design is based on the Saab 340B commercial airliner, while the Saab 2000 AEW&C is based on the Saab 2000 commercial airliner. As such, the airframe is the basically the same except that the former has the radar placed above the airframe, and other electronic equipment installed in the airplane. The airplane is of a dihedral wing design, which  means the wings are placed at the base of the airframe and angled upwards. It had two turboprop engines and an airframe built entirely of aluminium with the same construction techniques other Saab military fighters had: usage of bonding instead of rivets, reducing the overall weight of the airplane. It also has wider horizontal stabilizers, a vibration control system in the cabin to reduce the noise from the engines, and more powerful engines (the two General Electric CT7-9B turboprops of 1870 hp).

The wing and the horizontal control surfaces or stabilizers are dihedral, with the angle of the former being more prominent than the angle of the main wings. Both the wings and the horizontal stabilizers are both of trapezoid shape, being very thin – or simply not having that much of surface area. The engines are located at a quarter of the main wings, close to the main airframe. The main wings are located at the middle of the airframe, with the airframe being of tubular shape. The bow section of the airframe has a shape that varies according from the view or perspective. From an upper view, it has a parabolic nose cone; from a side view the shape is divided, with the area between the very roof and the windscreen having and inclination of around 38 degrees negative, and from the lower section of the windscreen to the tip of the nose, an angle of 30 degrees negative. The tip of the nose from a side view is placed at the lower section of the airframe, with the interior bow section from where the frontal landing gear is placed, to the tip, having an angle upwards of 10 degrees. The central section of the airplane is of cylindrical shape.

The aft or stern section of the airplane comprises the horizontal and vertical control surfaces, and two ventral tails fins. The tail is of conventional type with a sort of “double-delta” configuration; this is, the surface having at the forward area different angles. The forward section of the tail, from the central area of the airframe to the area where the horizontal control surfaces are placed, has an angle of nearly 15 degrees. From the aforementioned section to the tip of the tail the angle is of 45 degrees. From an upper view, the rear section is of conical shape, whereas from a side view the upper area of the aft section is lightly going downwards, and the interior part has an upwards angle of around 15 degrees. The ventral fins are placed right beneath the horizontal control surfaces. The rudder dominates half of the tail. And there is an elongating radome at the very rear part of the aircraft. The landing gear is of tricycle configuration, with the frontal landing gear placed at the nose cone (beneath the cockpit) and the two landing gear trains placed beneath the engine gondolas, them being retractable with storage inside the engine gondolas.

The Saab 2000 AEW&C has a similar structure to that of the 340, except that it is more elongated in width and length, the inferior section of the nose being entirely straight and the engines having more distance from the main fuselage. It also lacks the ventral tail fins the Saab 340B AEW&C (S 100B Argus) has.

The engines powering the aircraft are two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller. Thanks to the powerplant, the airplane can reach a maximum cruising speed of 524 km/h (325,60 mph). The aircraft is fitted with devices to reduce the noise generated by the engines. The Saab 2000 AEW&C is powered by two 2 Allison/Rolls Royce AE 2100A turboprop engines of 4,591 hp with a Dwoty Rotol six-bladed constant speed propellers each, allowing a cruise speed of 629,68 km/h (391,26 mph).

The AEW&C version has the Ericsson Erieye radar placed above the central section of the airframe, supported by a series of pillars that connects it to the main airframe and with a slight inclination downwards from stern to bow. Ventral antennas are installed at the inferior area of the fuselage.

The canopy is of conventional type, typical of any commercial or transport aircraft, with two frontal windscreens, and a lateral windscreen at each side of the cockpit. The crew on the Saab 340 AEW&C (S 100B Argus) is normally six.

Fitting a civilian for defence duties

Perhaps surprisingly, the Flygvapnet lacked an airborne AEW&C system during the late Cold War, relying instead on either smaller airborne assets for surveillance or land radar stations. The Flygvapnet decided to close this gap by ordering Ericsson Microwave Systems to develop the PS-890 Erieye radar by the late 80s, with the airframe that would be used undergoing the first trials by the same period. This idea was, in fact, proposed back in the 70s but rejected. It was revived again in the Swedish Parliament (Riksdag) in 1982. As the Boeing E-3 Sentry AWACS was deemed too expensive, it is no surprise that the Saab 340 airliner was chosen by the Swedish Defence Materiel Administration as the platform for the airborne radar system. the Flygvapnet was already operating with a Saab 340B which was being operated as a VIP transport. In any case, it was a very good decision, considering the Saab 340B is a very economic airplane thanks to its powerplant’s configuration and the advanced basis avionics and electronics, which was hence an economic alternative to the E-3 Sentry. In combination with the Erieye radar, it makes a suitable platform for an airborne radar for Sweden. The Saab 2000 is an example of how this concept has evolved by incorporating the Erieye into an equally economical yet very capable airframe, which a derivative from the basic model.

The Eye of Odin

The radar installed in the Saab 340B AEW&C (S 100B Argus) is the Ericsson Microwave System Erieye PS-890 multi-mode active electronically scanned array (AESA) pulse-doppler radar, which makes the airplane a very remarkable AEW&C aircraft, considering its capacities. Its development began in 1985 after the Swedish Defence Materiel Administration, with a dummy dual-sided phased antenna being tested on the future platform, which was tested in trial two years later. It has 200 solid-state modules mounted in the antenna, with an S-band frequency and 3 GHz, with a ‘look’ on each side of 120 degrees and a reach of up to 300-400 km at an altitude of 6096 meters (20,000 ft). It has an altitude reach of up to 20 km (65,000 ft), yet leaves the nose and tail areas as blind spots. This shortcoming is compensated by the fact the radar – with this design in particular – can provide improved detection and better tracking thanks to the electronically scanned beam, at the point of being able to scan other areas while concentrating on a single target. Moreover, the PS-890 Erieye can detect and track fighters, helicopters, cruise missiles and even very small targets at the sea, as it has also a sea surveillance mode. Moreover, sectors deemed important can be scanned with different modes at a single moment, being capable of performing in electronically saturated environments and as an all-weather device, and can discern between friend and foes through its IFF capacities and devices.

This is suitable for the Flygvapnet considering that the dimensions it has to watch for are the air and the sea (even more as the Baltic sea is the most important body of water at the East, an area from which most of the threats have come historically, and even currently). As such, it can perform air and sea surveillance missions, Command and Control, Intelligence, control of own assets, surveillance and control of national borders, national assets and national economic zones, search and rescue, alert warning and air policing. The system is compatible with NATO airborne systems and standards.

The Erieye PS-890 radar has other electronic features, such as adaptive waveform generation with digital; pulse-coded electronic frames; signal processing and targeting, a track while scan device; low and medium pulse repetition frequency operating modes; frequency agility; target radar-cross section display; and air-to-air and sea surveillance modes.

Interestingly and despite the system being capable of receiving four multifunction workstations for airborne controllers, it can spare them as it has instead an onboard automatic systems datalink that can transmit to ground station the information gathered by the airborne radar, and with those same stations being capable of transmitting orders to the platform. The airplane and radar are both connected to the integrated Swedish Air Defence System and network StriC-90, thanks to this network, the airplane can maximize its operational performance, complementing in turn and even enhancing the capabilities of such system; this fact makes the Saab 340B AEW&C (S 100B Argus) airplanes very valuable assets in the Flygvapnet. And the same design of the radar module was the first of its kind, being also an alternative to the disc-shaped classical airborne radars. The radar developed by Ericsson is fitted in other similar airborne platforms such as the Embraer EMB-145/E-99 and the Bombardier Global 6000. It has now evolved into the Global Erieye airborne radar.

Variants of the Saab 340 AEW&C (S 100B Argus)

  • Saab 340 AEW&C / S 100B Argus – Airplanes having the PS-890/FSR-890 radar, and operated by the Royal Thai Air Force.
  • Saab 340B AEW&C 200 – Version fitted with the IS-340 Erieye radar
  • Saab 340B AEW&C 300 / S 100D Argus – Airplanes fitted with the upgraded PS-890/ASC-890 radar, capable of admitting from 1 to 4 operators.

Variants of the Saab 2000 AEW&C

  • Saab 2000 Erieye AEW&C – Version fitted with an airborne Erieye radar
  • Saab 200 MPA (Maritime Patrol Aircraft) – Version for Maritime Patrol and capable of performing ASW, ASuW, anti-piracy/anti-narcotics/anti-people smuggling, maritime counter-terrorism operations, search and rescue, support for special forces, SIGINT, and fisheries patrol, among other sea-based security tasks.

Operators

  • Sweden – The Flygvapnet operates four Saab 340 AEW&C (S 100B Argus) fitted with the Erieye radar, alongside 2 additional airframes serving as transport planes, ready to have the radar installed in case it is needed. The first airframes were received in 1994, entering fully in service between 1997 and 1999, and serving in the F16M wing at Malmstatt. Normally, there are no operators onboard, being rather used as a part of the integrated air defence network.
  • Greece – The Hellenic Air Force decided to acquire the Erieye radar system with 4 units to be installed in Embraer RJ-145 airplanes. While waiting for the newly acquired system to arrive, 2 Saab 340B AEW&C airplanes were loaned by the Greeks in the year 2000. The loaned units were modified, having two to three operator consoles, NATO IFF, communications and datalinks having a ground bases system for information processing fitted for Greek standards, but lacking the Swedish ECCM and also the cockpit display processing information from ground stations. These airplanes were returned to the Flygvapnet by 2003.
  • Thailand – The Royal Thai Air Force has two Saab 340 AEW&C that received in October 2012.
  • United Arab Emirates – The United Arab Emirates Air force requested 2 airplanes, with the units delivered being Saab 2000 AEW&C. Now operational.
  • Saudi Arabia – The Royal Saudi Air Force reportedly operates two Saab 2000 AEW&C for border surveillance.
  • Pakistan – This country operates four Saab 2000 AEW&C airplanes. 2 more are reportedly on order.

 

Saab 340 AEW&C – S 100 B Argus Specifications

Wingspan 70 ft 4 in / 21.44 m
Length 66 ft 8 in / 20.33 m
Height 22 ft 11 in / 6.97 m
Wing Area 450 ft² / 41.81 m²
Engine Two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller.
Empty Weight 22,707 lb / 10,300 kg
Maximum Takeoff Weight 29,101 lb / 13,200 kg
Loaded Weight 7,500 lb / 3,401 kg
Climb Rate 2,000 ft / 10,2 m/s
Maximum Speed 285 mph / 528 kmh
Cruising Speed 285 mph / 528 kmh
Range 900.988 mi / 1,450 km
Maximum Service Ceiling 25,000 ft / 7,620 m
Crew 6
Electronics
  • An Ericsson Erieye (PS-890) radar.
  • Länk 16, HQII, IFF, secure voice, m.m.

 

Saab 2000 AEW&C Specifications

Wingspan 81 ft 3 in / 24.76 m
Length 89 ft 6 in / 27.28 m
Height 25 ft 4 in / 7.73 m
Wing Area 600 ft² / 55.7 m²
Engine Two Allison/Rolls Royce AE 2100A turboprops of 4152 hp with a Dowty Rotol six-blade constant speed propeller.
Empty Weight 30,424 lb / 10,800 kg
Maximum Takeoff Weight 50,625 lb / 22,800 kg
Loaded Weight 13,010 lb / 5,900 kg
Climb Rate 2,250 ft / 11,4 m/s
Maximum Speed 391,26 mph / 929,68 kmh
Cruising Speed 391,26 mph / 929,68 kmh
Range 2,301.55 mi / 3,704 km
Maximum Service Ceiling 30,000 ft / 9,144 m
Crew 7
Electronics
  • An Ericsson Erieye (PS-890) radar.
  • Länk 16, Self-protection systems, IFF/SSR, secure voice, ESM/ELINT, AIS; Command and Control devices such as consoles and a latest generation HMI.

Gallery

Saab 340 AEW Blueprint

 

 

Sources

Deagel.com. (2017). Saab 2000 AEW&C., Forecast International. (2000). Saab 2000 (Archived Report)., Fredriksson, U. (2004). Saab 340AEW. X-plane.org., Pike, J. (1999). S 100B Argus, Saab 340 AEW&C. FAS.org., SAAB. (n.d.). SAAB 2000 Erieye AEW&C Airborne Early Warning & Control., SAAB. (2009). SAAB 340B/Bplus. SAAB Aircraft Leasing. SAAB. (2013a). Erieye AEW&C Mission System., SAAB. (2013b). SAAB Airborne Surveillance Solutions. SAAB. (2015). High Quality and Support in Focus – Saab 340 & SAAB 2000., SAAB. (2016). The First Airborne Radar in Sweden Underwent Final Testing 20 Years Ago., SAAB. (n.d.). Erieye SAAB 2000 AEW&C System. The Spyflight Website. (2003). SAAB S100B AEW&C Argus. Images: 340AEW Royal Thai Airforce by Alec Wilson / CC BY-SA 2.0, 340AEW by Gnolam / CC BY-SA 3.0,  Side Profile Views by Ed Jackson – Artbyedo.com