Farnborough Air Show

Latest Gripen Demo goes through its paces

 - July 7, 2008, 6:22 AM

Saab achieved the first flight of the Gripen Demo from the company’s Linköping airfield in Sweden on May 27.  Crewed by test pilots Mikael Siedl and Magnus Ljungdahl, the flawless 30-minute flight marked the start of a three-year campaign, during which the fighter will demonstrate a wide range of new technologies destined for the Gripen Next Generation aircraft, as well as options for existing models.

At first glance the Gripen Demo looks like any other two-seater, but a closer examination reveals a much-changed lower central fuselage and wingroot area. By moving the main undercarriage units from the lower fuselage to fairings under the wingroots, greater internal fuel capacity is provided–an increase of 40 percent to 7,275 pounds. The extra clearance during undercarriage retraction allows two large stores pylons to be fitted under the fuselage either side of the existing centerline hardpoint.

With its extra fuel capacity the Demo has an impressive range capability on internal fuel, which can be augmented by up to 8,377 pounds of external fuel, an increase of 33 percent. Engineers are developing the ability to jettison tanks at supersonic speeds. Saab claims a ferry range of 2,200 nm for the Demo, compared with 1,640 nm for the earlier JAS 39C/D.

The Gripen Demo weighs 7.1 tons empty, with a basic design flight weight of 9.1 tons. Maximum takeoff weight is 15,652 pounds. The aircraft is powered by a General Electric F414G turbofan, offering a 35-percent increase in thrust. The extra power easily offsets any weight increases, and affords significant provision for future weight growth. The F414G allows the Gripen Demo to easily supercruise in an air defense configuration. Increased mass-flow requirements have dictated an increase in intake size of about 10 percent.

Complementing the flying demonstrator is a ground-based avionics rig. The Gripen Demo program encompasses a complete review of the aircraft’s systems, centered on new computers and a high-bandwidth databus system. New avionics systems will be tested first in the dedicated ground rig before migrating to the flying aircraft.
The advances focus on improvements in software safety and criticality, capacity and performance, and efficient functional development. Thanks to the adoption of the latest Arinc 653 integrated modular avionics standard, areas of the system can be segregated to allow rapid integration of new functions. By using Arinc 653 partitions, new functionality can be added and verified separately, without having to re-test the whole system.

AESA Radar Available
Saab Microwave Systems has teamed with Thales to provide an active electronically scanned antenna radar for the Gripen. Saab provides the radar back-end, based on the Gripen’s existing PS-05/A but with an upgraded single data processor and exciter/receiver. Thales provides the antenna array, based on the technology it has already begun testing for the Rafale.

Development of the Demo radar began  last fall, and by early spring 2008 the integration of subsystems had begun. In early 2009, the radar will be integrated into the aircraft, leading to the start of flight trials in the summer. Customer demonstrations are scheduled to begin in the fall of that year. An infrared search and track sensor is also to be offered, forming part of the Indian bid.

To survive in a future battlespace the Gripen will need sophisticated defensive systems. The current EWS 39 suite in the JAS 39C/D is already highly advanced,
but it is being developed to enhance the aircraft’s survivability. The main upgrade elements are the addition of a missile approach warning system (MAW), improved digital radio frequency memory (DRFM), and options for podded systems such as jammers for electronic attack, and towed radar decoys.

The MAW-300 system is being installed in the Demo aircraft, and part of the evaluation is to determine whether four sensors are sufficient, as opposed to the six used in other installations. The MAW-300 uses ultraviolet technology, but Saab plans to test a two-color IR system in the future.

The new EW system has enhanced direction-finding, and offers passive ranging and elevation measurement, making it a highly useful tool in the ESM/Elint role. The advanced DRFM allows the EW suite to provide a range of jamming options, including noise, deception and false target generation.

Also incorporated are mechanical countermeasures in the form of BOL chaff dispensers in the rear of the four underwing pylons. The BOP-C dispensers are mounted above and below the rear fuselage on either side of the fin. They fire IR flares upward and downward, with options for reactive or pre-emptive flare protection. The outer wing pylons can also mount launchers for towed radar decoys, while external jamming pods can be carried under the intake pylon.

The Gripen Demo has 10 stores-carrying stations, all of which are Mil Std 1760 compliant. It capitalizes on the advanced weapons integration work already being undertaken for the JAS 39C/D, adding GPS-guided bombs such as JDAM or Small Diameter Bomb (SDB). New weapons such as the Kongsberg NSM are envisaged for the Demo.

New racks have been designed to allow multiple weapons carriage on each pylon. It can carry up to 32 SDBs, or up to six 2,000-pound class weapons, plus a targeting pod. Double-carriage of Meteor BVRAAMs allows the Gripen Demo to carry four of the weapons, plus a pair of IRIS-Ts and drop tanks, and still leave the fuselage pylons free for air-to-ground ordnance.

As its name suggests, the Gripen Demo program is a technology demonstration/ insertion campaign for the whole Gripen family. However, the improvements being tested are those that are most likely to feature in a third generation of production aircraft, and the Demo aircraft will become a de facto prototype for what is being dubbed Gripen NG (Next Generation). The new version should be available for delivery starting around 2015.

On April 28, just five days after the Gripen Demo aircraft was revealed to the world, Gripen International submitted its Gripen IN proposal for the 126-aircraft Indian combat aircraft competition. On the same day, an FMV team handed over the response to a Norwegian Request for Binding Information covering the supply of 48 Gripens. Both bids are based on the Gripen NG, as is the proposal to Denmark.