If most of the Sea Harriers had been lost, the GR.3s would have replaced them in air patrol duties, even though the Harrier GR.3 was not designed for air defence operations; as such the GR.3s quickly had their outboard weapons pylons modified to take air-to-air Sidewinder missiles. From 10 to 24 May 1982, prior to British forces landing in the Falklands, a detachment of three GR.3s provided air defence for Ascension Island until three F-4 Phantom IIs arrived to take on this responsibility. During the Falklands War, the greatest threats to the Harriers were deemed to be surface-to-air missiles (SAMs) and small arms fire from the ground. In total, four Harrier GR.3s and six Sea Harriers were lost to ground fire, accidents, or mechanical failure. More than 2,000 Harrier sorties were conducted during the conflict—equivalent to six sorties per day per aircraft.