Monday, November 12, 2007

JAS 39












Gripen Multi-Role Fighter Aircraft, Sweden

The Gripen multi-role fighter aircraft, developed by Saab, was first flown in December 1988 and entered operational service with the Swedish Air Force in 1997. It is planned that the Gripen will replace all current variants of the Viggen and Draken combat aircraft.

Gripen has been developed by an industrial consortium consisting of Saab, Ericsson Microwave Systems, Volvo Aero Corporation, Saab Avionics and FFV Aerotech. A joint venture company, Gripen International, has been set up by Saab and BAE Systems to market the Gripen for export markets. BAE Systems is building the main landing gear unit and wing attachment unit.
JAS 39A is the single-seater version of the Gripen. A two-seater JAS 39B operational trainer variant of Gripen is available. The JAS 39B is equipped with the same avionics and weapons suite as the JAS 39A, with the exception of the gun. JAS 39C is the single seat batch 3 and export standard version, which was first delivered to the Swedish Air Force in September 2002.
JAS 39C has colour cockpit displays, an On-Board Oxygen Generation System (OBOGS) and in-flight refuelling capabilty. JAS 39D will be a similarly upgraded to a two seater.
The Swedish Air Force has ordered 204 Gripen (including 28 of the two-seater version) for two operational squadrons, with deliveries continuing till 2008.
If approved by the Swedish government, Saab intends to begin a Gripen demonstrator programme to develop an upgraded version of the JAS39C. Saab has selected the GE Aviation / Volvo Aero F414G engine to power the demonstrator. The F414G has 96kN (22,000lb) thrust and will be fitted with Full Authority Digital Electronic Control (FADEC). Saab Microwave Systems will develop an Active Electronically Scanned Radar (AESA) for the programme.
In November 1998, the South African Air Force ordered 28 Gripen multi-role aircraft (19 single-seat and nine dual-seat). Denel Aviation of South Africa will produce part of the centre fuselage.


The first flight was in November 2005 and deliveries are to begin in 2008. In November 2001, Hungary signed a memorandum of understanding for the lease of 14 aircraft – 12 JAS 39A single-seat and two JAS 39B. In February 2003, Sweden and Hungary signed an amendment to the lease contract and both the single-seated and the twin-seated aircraft will be upgraded to C and D standard. The amendment also says that Hungary will purchase the aircraft after the lease period. Deliveries will begin in 2006.
In June 2004, the Czech Republic signed a leasing agreement with the Swedish Government for 14 new Gripen (12 single-seat JAS 39C and two two-seat JAS 39D) for a period of ten years. The aircraft were delivered between April and August 2005.


GRIPEN COCKPIT


The cockpit is equipped with a Saab Avionics EP-17 electronic display suite, with three multifunction displays and a wide-angle, 22x28 degree diffraction head-up display. The central head-down display provides tactical data superimposed on a computer-generated map. The displays on the left and right provide the flight data and the target data from the sensor suites.

BAE Systems and Saab Aerospace, with Denel Cumulus of South Africa, have developed an Integrated Helmet-Mounted Display (IHMD) system for the Gripen, known as Cobra. The IHMD is a development of the Striker helmet developed for the Eurofighter Typhoon. Cobra will equip the Gripen for South Africa.
The time-critical systems controls (for example, weapons and communications) are grouped on the throttle and control stick for hands-on throttle and stick (HADES) operation. The flight control system is a triplex digital fly-by-wire system from BAE Astronics and Lockheed Martin.
FIGHTER AIRCRAFT WEAPONS

The Gripen has seven external hardpoints for carrying payloads: one at each wingtip, two under each wing and one on the fuselage centreline.
The air-to-air missiles include MBDA (formerly Matra BAe Dynamics) MICA, Raytheon AIM-120B AMRAAM and Lockheed Martin / Raytheon Sidewinder AIM-9L (Swedish Air Force Designation RB74).


Sidewinder, mounted on the wingtips, is an all-aspect attack, short-range missile for enhanced dogfight capability. Air-to-surface missiles include the radar-guided Saab RBS15F anti-ship missile and Raytheon Maverick missile.
Later versions of the aircraft for Sweden will be armed with the short-range Diehl BGT Defence IRIS-T air-to-air missile and the MBDA Meteor Beyond Visual Range (BVR) air-to-air missile. Deliveries of IRIS-T began in December 2005. Meteor is due to enter service in 2010.
The Saab Bofors / MBDA Taurus KEPD 350 long-range standoff missile, with a range of 350km, has been successfully flight tested on the Gripen.
The internally mounted 27mm Mauser high-energy gun can operate in an automatic radar-guided aiming mode. The stand-off dispenser is the DWF39 from EADS (formerly DaimlerChrysler Aerospace) and Bofors. The Bofors ARAK 70 rocket pod is cleared for carriage on the Gripen.

COUNTERMEASURES SUITE


Saab Avionics is responsible for the EWS 39 electronic warfare suite, which has been ordered by the Swedish Air Force. EWS 39 is an integrated EW system that provides radar warning, electronic support measures and chaff and flare decoy dispensers.


GRIPEN SENSORS


The Ericsson PS-05 long-range multi-purpose pulse Doppler radar has air-to air operating modes covering long-range search, multi-target track-while-scan, multiple priority target tracking, air combat quick search modes, raid assessment and Beyond Visual Range (BVR) missile mid-course updates.
The air-to-surface modes include long-range search/target identification, multiple priority target tracking, high-resolution, real beam mapping, air-to-surface ranging and Doppler Beam Sharpening (DBS).
The aircraft is equipped with a Forward-Looking Infrared (FLIR) sensor and will have the Saab IR-Otis Infrared Search and Track system (IRST).
Nine Swedish Air Force Gripens are being fitted with the SaabTech Modular Reconnaissance Pod, which includes a Recon / Optical CA270 infrared sensor. The system will enter service in 2006.

COMMUNICATIONS


The aircraft has VHF / UHF transmitters and receivers from SaabTech Vectronics, and a Thales TSC 2000 Identification Friend or Foe (IFF) system. An air-to-air data link allows real-time exchange of tactical data within and between cooperating air units.
In the attack and reconnaissance role, the data link allows radar-derived surface data to be transferred from one Gripen to a group of radar-silent attacking aircraft.

ENGINE

The RM12engine, supplied by Volvo Aero, is a development of the GE F404 engine from General Electric. A digital engine control system automatically monitors the engine parameters and automatically switches on the back-up systems if required. A condition monitoring system registers the flight data.
The air-to-air refuelling probe is retracted into the aircraft to retain the aerodynamic profile. The longer flight times achieved by using air-to-air refuelling results in the pilot needing a larger oxygen supply, so an On-Board Oxygen Generating System (OBOGS) has been installed.