The Royal Air Force's Jaguars are equipped to stand off and deliver.
Douglas Barrie/BOSCOMBE DOWN
Urgent operational requirements (UORs), by their very nature, are not always easy to meet. Haste and progress are not always compatible. The UK Ministry of Defence (MoD) was lucky, however, with its UOR41/94 to provide a laser-designation-capability for the Sepecat Jaguar GR.1 because a technology-demonstrator programme (TDP) was already under way using a Jaguar airframe.
The UOR 41/94 was endorsed by the MoD in June 1994. The task was to integrate the GEC-Marconi Thermal Imaging and Airborne Laser Designator (TIALD) pod on to 12 Jaguar GR.1s. The aim was to bolster the Royal Air Force's laser-designation capability, which is now dependent on the Panavia Tornado GR.1.
The requirement had emerged after a visit to Bosnia by the then Chief of Defence Staff, Marshal of the RAF Sir Peter Harding. He directed the MoD to "...investigate the feasibility of providing all offensive aircraft types with an airborne laser-designation capability," says Wg Cdr Mike Gordon, Air Offensive 7, MoD.
The Jaguar was deemed to be the most cost-effective short-term option, although the system will eventually also be integrated with the British Aerospace Harrier GR.7.
The MoD, however, did not need to start from first principles on the Jaguar/TIALD integration project. The UK's Defence Research Agency (DRA) had been working on a TDP to examine the feasibility of single-seat aircraft laser-designation operations, at the behest of the MoD, since 1991.
Attempting to carry out laser target-designation in a single-seat aircraft presents specific problems. There is no clear consensus among air forces operating with laser designators as to the effectiveness of such an approach.
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The French air force uses the Thomson-CSF ATLIS laser-designator pod mounted on the centreline section on its single-seat Jaguars. The DRA's preference, although the TIALD has been mounted on the same station, is to put the pod on an in-board wing pylon.
The Royal Singapore air force has recently decided against using the Martin Marietta LANTIRN system on the single-seat Lockheed F-16C. Instead, it will use two-seat F-16Ds configured for the precision-strike role. Aircrew workload is believed to have been the main concern.
In exploring the issues, the DRA had configured a two-seat Jaguar T.2A (XX833) as a flight-trials demonstrator and TIALD testbed. Flight trials of the so-called "Nightcat" Jaguar took place in the first half of 1993.
Peter Tanner, the DRA's programme manager for both the Nighthcat trials and the UOR, says that certain key criteria quickly became apparent for single-seat TIALD operations. "The operation of a complex targeting system, designed for use on a two-crew aircraft, could not be simply transferred for use by a single pilot," Tanner points out.
The pod needed to be "...fully integrated with the avionics/weapon system. The integration must be such that any additional pilot workload is minimised, and the pilot must have adequate situational awareness to maintain flight safety".
For the single-seat requirement, the DRA established the following criteria:
high pointing accuracy. The pod had to be harmonised with the inertial-navigation/global-positioning system (INS/GPS) in pitch, roll and yaw axes;
high sightline stability;
aimpoint refinement;
adequate situational awareness;
system control - wherever possible, the control of the TIALD was automated;
track-loss reversion.
The research programme was complete by August 1993. While it showed that TIALD operation in a single-seat environment are feasible, it also indicated the need for considerable avionics modifications to the in-service Jaguar aircraft for TIALD operations.
As Tanner explains, the modifications to the Nightcat cockpit and aircraft included "a new head-up display and colour head-down display; a GPS; a modified inertial-navigation system; a digital map; computer-symbol generator; a new hand controller and stick top; and a 1553B databus".
The scope of the upgrade was such that it "...effectively trebled the software content within each modified aircraft", notes Tanner.
Situational awareness
Operational use of the TIALD pod would require the pilot to be in a head-down mode in the cockpit during the designation sequence. The imagery from the pod is displayed on the cockpit head-down display.
Tanner points out that, "...to prevent a loss of situational awareness when observing the TIALD video display, a special symbol format was overlaid on to it". This provides the pilot with an "attitude, height and speed display".
During the Nightcap trials, partner and self-designation missions were simulated. Self-designation, using a Toss attack (where the bomb is lobbed in a parabolic trajectory) was shown to be achievable during the flight trials.
In certain instances, says Tanner, targets "...could remain obscured until after the aircraft had pulled up. The pilot had therefore to be confident that the sightline would point at the target accurately throughout the attack. This was achieved successfully, using data provided by the INS/GPS system."
The June 1994 endorsement of UOR41/94 saw the DRA's TDP programme become the baseline for an in-service Jaguar modification programme.
The UOR, says Tanner, called for the "...modification of three single-seat Jaguar aircraft within six months, followed by the remaining seven single-seat aircraft and two, two-seat aircraft within a further 12 months".
In August 1994, the DRA was awarded a £2 million contract to take the lead role in implementing the requirement. This included a further three-month flight-test programme using the Nightcat aircraft "...to convert the system moding and software from a research to an operational standard", along with "the design, installation and flight test of the modified GR.1 aircraft".
Part of the flight-test programme was intended to ensure that the TIALD pod did not lead to "adverse handling problems", says Tanner. Drop trials of the Texas Instruments Paveway laser-guided bomb were also carried out, with the TIALD-pod-equipped aircraft showing "minimal unfavourable carriage effects". The Jaguar will be cleared for carriage of both the Paveway II and Paveway III laser-guided bombs.
So far, three aircraft have been modified at the DRA's Boscombe Down site. The second and third aircraft were modified by a team from RAF St Athan, with the DRA "hand-holding" them through the programme. The other aircraft to be modified for TIALD carriage will be taken to St Athan.
Sqn Ldr Cliff Christensen, Jaguar Support Authority, Headquarters Logistics Command, says: "When the modification was first designed, it had been estimated that it could take up to 3,500 man hours to install." As experience built up, however, the work content was reduced to "about 1,500 man hours." St Athan's aim, Christensen says, is to achieve an aircraft turn-round within an elapsed time of 50 days.
Two aircraft-modification tracks have been set up at St Athan, with the first two of the remaining nine aircraft already under modification. Christensen notes: "By the end of November, they aim to have all aircraft completed, one month ahead of schedule."
The revamped aircraft, redesignated the GR.1B, will provide the Jaguar fleet with an extended operational capability and, in all likelihood, an extended lease of life. The RAF intends that the main elements of the upgrade, except for the TIALD pods, be introduced into the whole Jaguar fleet.
On time, and within budget, the project is the exception to the rule when it comes to MoD procurement programmes. It is a programme of which the DRA is justifiably proud, as are the industry and RAF participants.
Source: Flight International
