In a peculiar twist of fate, an aircraft whose series-production ended in 1999 continues to be selected as the preferred platform for airborne early warning and control (AEW & C), with its two latest customers now being the air forces of Pakistan and Thailand. While Pakistan would be procuring four Saab 2000-based AEW & C platforms (all ex-Air France airframes) Thailand will acquire two smaller Saab 340-based AEW & C systems. The Saab 2000 AEW & C programme got underway in June 2006, when launch customer Pakistan finalised the purchase of six operational platforms.
This contract was revised in May 2007 when Pakistan decided to acquire only four AEW & C platforms, with the remaining two Saab 2000s being cannibalised for spares. Currently, there are only a total of 50 out of 63 Saab 2000s that remain in airline service, with the remainder 13 being retained by Saab Aircraft. It is these aircraft that are being relifed and modified as AEW & C platforms.
In the case of Thailand, Bangkok agreed on October 16 last year to go ahead with a Baht34.4 billion (USD 1.086 billion) programme that calls for the procurement of 12 JAS-39C/D Gripen medium multi-role combat aircraft and two Saab 340 AEW & Cs. While the first six Gripens and one AEW & C platform worth Baht19 billion (USD 607 million) ...
will be procured between 2008 and 2012, the remaining aircraft worth Baht15.4 billion (USD 492 million) will be ordered between 2013 and 2017.
These aircraft will be based at the Royal Thai Air Forces (RTAF) existing air base at Ubon Ratchathani (under 21 Wing) and an expanded and upgraded air base at Surat Thani (under 7 Wing). The first Saab 2000 AEW & C platform for the Pakistan Air Force (PAF) will be delivered this October.
The Saab 2000 is one of the fastest turboprop aircraft in existence, being able to cruise at a speed of more than 665kph (360 Knots). It made its maiden flight on 26 March 1992 and entered commercial airline service in 1994, a few months after its certification by the Joint Aviation Authorities in March and the Federal Aviation Administration in April. The Saab 2000s powerplant comprises twin Rolls-Royce AE-2100 turboprop engines, each driving six-bladed Dowty Rotol propellers. The aircrafts service ceiling is 31,000 feet, and the cockpit is equipped with a Rockwell Collins Pro Line 4 avionics suite with integrated avionics processor, engine indication and crew alerting system, traffic alert and collision avoidance system, attitude heading and reference system, and a digital air data system. Cabin noise is reduced by an active noise control system comprising 72 microphones and 36 speakers, which generate anti-phase noise.
Each of the four PAF Saab 2000 AEW & C platforms will be equipped with the FSR-890 Erieye radar built by Ericsson Microwave Systems. The S-band Erieye is a pulse-Doppler active phased-array radar operating within the 2GHz to 4GHz bandwidth. The 8 metre-long, 900kg antenna will be mounted on the upper dorsal spine of the Saab 2000s fuselage. The radars dorsal unit (DU) will include the carbon-fibre radome, antenna array, RF distribution network, and 192 transmit/receive modules that will be cooled by ram-air. Each such module will comprise a power amplifier for the transmitted microwave signal, low-noise amplifiers as front-ends for the receiver channels, and phase shifters for accurate control of the signal phase in both transmit and receive modes. In the latter, amplification of the signal will be controlled as well. The phases and amplitudes will be continuously calibrated. Each T/R module will be connected to one vertical slotted waveguide on each side. An electronic switch in the module will select the side. By feeding the slotted waveguide separately in the upper and lower half, the beam will be shifted in elevation for height measurement. This shifting will be conducted by single-step phase shifters in the front-ends of the modules. A module-control databus will provide control of the modules to achieve instantaneous antenna beam-steering and the very low sidelobes required.