The MLU programme involved advances in systems, stealth technology and avionics. A 1553 digital avionics data-bus linked the new systems and fully integrated the aircraft’s improved defensive aids suite. The weapons bus was configured to control the release of a wide range of weapons and was adaptable for future weapon types through the system’s missile control (later removed) and weapon programming units.

Upgraded navigation systems, included a global positioning system (GPS), BAE Systems Terprom digital terrain mapping system and Honeywell H-764G laser inertial navigation system (INS), were now integrated into the aircraft’s main avionics system via the databus. The front cockpit was also fitted with a new pilot’s head-up displayand a Pilot Multi Functional Display (PMFD) and digital map. The GR4 was equipped with forward-looking infrared (FLIR). The thermal image is projected onto the pilot’s head-up and head-down displays.

The BAE Systems TIALD thermal imaging laser designator pod, which provided high-accuracy autonomous guidance for laser-guided weapons was integrated on the upgraded aircraft. From February 2007, a number of GR4 aircraft operating in Iraq were fitted with the Rafael ‘Litening’ III targeting pod.

The GR4 was cleared to carry enhanced Paveway II bombs, with GPS/INS (global positioning system / inertial navigation system) guidance. Raytheon was awarded a contract to integrate Paveway IV on the Tornado in February 2008, which was completed in July 2009.

The aircraft were armed with the Brimstone anti-armour missile system, which entered service with initial operational capability (IOC) on the GR4 aircraft in March 2005, and Storm Shadow cruise missiles, which entered initial operational service on the Tornado aircraft in March 2003, in support of Operation Telic.

The GR4 could also deploy the Goodrich Raptor reconnaissance pod which replaces the current Thales Optronics (Vinten) VICON system. Raptor consists of the DB-110 reconnaissance system with CCD day sensor and mid-wave indium infrared sensor. It provided real-time day and night targeting with a range of 72km (electro-optic) and 36km (infrared). The pod received initial operating capability in September 2002 for deployment in Operation Telic in 2003.

The GR4 underwent a further cockpit upgrade consisting of a new Astronautics pilot’s multifunction display and the BAE Systems TARDIS (Tornado advanced radar display and information system).

In 2009, the Tornado replaced the Harrier force in Afghanistan where it took part in intelligence gathering for coalition forces.

Two years later it was involved in Operation Ellamy against Colonel Gaddafi in Libya.

The aircraft has also performed duties in Kosovo, Libya, Afghanistan, and more recently against Daesh in Iraq and Syria.

In addition to launching air strikes, the fighter jet was also able conduct intelligence gathering missions and was armed with a variety of Paveway bombs, Brimstone air-to-air missiles and Storm Shadow cruise missiles.

The aircraft also possessed an Advanced Short Range Air-to-Air Missile (ASRAAM) for defensive purposes.

When deployed in an armed reconnaissance or close air support role, it would usually be armed with a mix of Paveway IV and Dual-Mode Seeker Brimstone, combined with a Litening III targeting pod, and in addition to the internal 27mm gun.