<Tr> <Td_colspan="2"> Footage of Harrier II HUD during flight </Td> </Tr> <Tr> <Td_colspan="2"> Harrier GR9 flight demonstration </Td> </Tr> <P> The RAF used Harriers in the ground attack and reconnaissance roles, so they relied on the short - range AIM - 9 Sidewinder missile for air combat . The Sidewinder had proven effective for Royal Navy's Sea Harriers against Argentinian Mirages in the Falklands conflict; however, from 1993 the Sea Harrier FA2 could also carry the much longer - range AIM - 120 AMRAAM, a radar - guided missile . The Sea Harrier had a radar since its introduction and the USMC later equipped their AV - 8B Harriers with a radar as part of the AV - 8B+ upgrade; however Britain's Harrier IIs never carried a radar . When the Sea Harrier was retired, it was suggested that its Blue Vixen radar could be transferred to the Harrier IIs . However, the Ministry of Defence rejected this as risky and too expensive; the Armed Forces Minister Adam Ingram estimated that the cost would be in excess of £ 600 million . </P> <P> Even prior to the Harrier GR5 entering service, it was clear that alterations were required for the aircraft to be more capable in the interdictor role . A more advanced model, designated as the Harrier GR7, was developed primarily to add a night - time operational capability and avionics improvements . The GR7 development programme operated in conjunction with a similar USMC initiative upon its AV - 8B Harrier fleet . Additional avionics include a nose - mounted forward - looking infrared (FLIR) and night vision goggles, an electronic countermeasures suite, new cockpit displays and a replacement moving map system . The GR7 conducted its maiden flight in May 1990 and entered service in August 1990 . Following the full delivery of 34 Harrier GR7s in 1991, all of the GR5s underwent avionics upgrades to become GR7s as well . </P>

What is the primary role of the harrier gr9
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