The Panavia Tornado GR4's progress from paper project to production has been far from smooth, the development path being littered with delays, the danger of cancellation and a critical National Audit Office report.
The Royal Air Force finally received the first two of a total of 142 GR4s at the end of October, with deliveries due to be completed during 2002. The aircraft's planned initial service date is September 1998, with the first aircraft being delivered to RAF Bruggen, in Germany.
The Tornado mid- life update (MLU), Staff Requirement (Air) 417, had its genesis in the mid-1980s and was created because the Tornado GR1's survivability in penetrating heavily defended Warsaw Pact airspace at low level needed to be improved. The Tornado's primary task was in the tactical nuclear-strike role, to deliver the WE177 free-fall bomb against pre-assigned Warsaw Pact targets.
The RAF, in the nature of upgrade projects, started by looking at what was possible, including the insertion of an airframe fuselage plug to provide extra fuel capacity, before narrowing its wish list down to the probable, and then finally to what is now referred to as MLU88.
The service had planned to order 26 new-build GR4s, as well as converting the bulk of its Tornado fleet, as its batch eight procurement, but this was cancelled in 1990.
The driver behind the MLU 88 upgrade was to provide a fully automated, covert, low-level-penetration capability.
In addition to an improved avionics architecture, new displays and sensors were included - including a forward-looking infra-red (FLIR), new armament and control, and terrain-reference navigation (TRN) systems and covert radio altimeter. The additions of the FLIRand TRN were intended to allow the Tornado to be flown at low level without the necessity of using any active emitters - primarily the terrain-following radar (TFR).
The FLIR is limited, however, in having a forward field of view only, so it was supplemented with night-vision goggles (NVGs) and a compatible cockpit.
Subsequent events and ensuing budgetary constraints then conspired against the MLU 88 programme, however, after the components of the update had been chosen.
The underlying rationale for the MLU 88 was built on the premise that the RAF's primary mission would be to fight a war in the Central European theatre against Warsaw Pact forces. In addition, the 1990-1 Gulf War provided the service with a taste of the kind of future air operations with which it was likely to be tasked.
In the Gulf War, the RAF used the Tornado GR1 in a variety of roles, including offensive counter-air, air-interdiction, suppression of enemy air defence, and tactical reconnaissance. After initially deploying the aircraft at low level, the service switched to a medium-level campaign, revealing what air force sources describe as "a number of sub-optimal areas". The GR1's sensors, for instance, were optimised for low-level operation. Medium-level operations revealed a problem of " poor target acquisition with radar".
The GR1's limitations in the medium-level role were addressed by rushing into the field two pre-production GEC-Marconi Thermal Imaging Airborne Laser Designator (TIALD) pods to supplement the Pavespike designators already deployed on Blackburn Buccaneers.
The MLU programme also became ensnared in the then Conservative Government's apparently rolling defence reviews, with Treasury officials viewing the project as a "big, big target". This resulted in a much-reduced scope for the MLU, the most visible element to suffer being the GEC Spartan TRN, which was deleted from the programme. Originally costed at around £1 billion ($1.6 billion), the eventual budget was cut to £750 million.
Ditching the TRN deprived the GR4 of an all-weather, night-covert-penetration capability because the FLIR is weather dependent, while the NVGs require adequate ambient light. Given certain conditions, a GR4 crew will have to resort to the active-emitter TFR to prosecute a mission at low level.
The FLIR/NVG combination, however, will allow RAF Tornado units a more flexible approach in planning night missions. With the GR1, mission planning was heavily based around timing and track lines: with the GR4 crews will be able to use more day-formation-like tactics. The RAFis also looking at using the FLIR to allow night medium-level dive attacks.
The effect of these pressures has forced the RAF to "revisit MLU 88". Offsetting the deletion of the TRN, a global-positioning system (GPS) and a TIALD pod were added to the new package, dubbed MLU 93.
This package was eventually approved in 1994, covering the upgrade of 142 aircraft to GR4 standard. An initial service date of 1998 was specified.
One of the problems facing prime contractor British Aerospace, which was awarded the MLU contract in mid-1994, was the Tornado fleet mix. The RAF operates seven different modification standards of Tornado GR1, which it admits has resulted in "supportability problems". One of the side benefits of the MLU will be to bring all of the GR4s to the same baseline standard, with the exception of the reconnaissance GR4A's infra-red linescan system.
Before being delivered to Warton, all of the 142 aircraft to be upgraded will go to RAF St Athan for what is described as a pre-input maintenance programme, to bring them all to a common standard.
A total of 17 Tornado GR1s will have been returned for upgrades at BAe Warton by the end of this year, and work will be carried out on more than 20 aircraft a year from 1998 up to the completion of the programme.
Since the MLU was set in train, the Ministry of Defence has also placed contracts for several weapons for which the GR4 is a key platform: SR(A) 1242 for the Texas Instruments Paveway III laser-guided bomb, SR(A)1236 for the Matra BAe Dynamics Storm Shadow stand-off missile and SR(A) 1238 for the GEC-Marconi Brimstone anti-armour missile .
The Paveway III, with the TIALD400 Series pod, six-channel video and full integration of the Matra BAe Sea Eagle, are included in an additional GR4 work project, Package 1. The Storm Shadow, Brimstone and the Hughes RAPTOR reconnaissance pod are included in Package 2.
Beyond this, Packages 3 and 4 are also envisaged to cover such areas as the possible introduction of a missile-approach warning system, successor identification friend or foe, as well as a version of the Joint Tactical Information Distribution System (JTIDS). The JTIDS is being introduced on the Tornado F3 air-defence aircraft first. A hands-on-throttle-and-stick modification may also eventually find its way on to the GR4.
The Tornado GR4 may also receive the Miniature Air-Launched Decoy as well as whichever system emerges to meet the RAF's requirement for an improved-accuracy free-fall bomb - although whether this requirement is eventually addressed by purchasing GPS-based modification kits, or an off-the-shelf purchase of the Boeing Joint Direct Attack Munition, remains to be seen. The aircraft may also be fitted with the GEC Marconi towed radar decoy.
Alongside the RAF's GR4 programme, the Royal Saudi Air Force (RSAF) may also implement a similar upgrade for its Tornado Interdictor Strike fleet.
The RSAF has been briefed by both the RAF and the MoD on the project.
As well as the GR4 upgrade, the Saudis are also interested in purchasing both a short-range tactical air-launched anti-armour weapon, and a long-range precision strike missile. The Brimstone and the Storm Shadow are being considered to fulfil these requirements.
The RAF's present planned out-of-service date for its Tornado GR4 fleet is 2018, although there are those close to the programme who firmly believe that the aircraft will stay in service beyond 2020, before it is eventually replaced by the Future Offensive Air System, whatever this eventually turns out to be.