Initial infiltrations were noticed in Kargil in early May, 1999. Because of the extreme winter weather in Kashmir, it was common practice for the Indian and Pakistan Army to abandon forward posts and reoccupy them in the spring. That particular spring, the Pakistan Army reoccupied the forward posts before the scheduled time.
By the second week of May, an ambush on an Indian army patrol acting on a tip-off by a local shepherd in the Batalik sector led to the exposure of the infiltration. Initially with little knowledge of the nature or extent of the encroachment, the Indian troops in the area initially claimed that they would evict them within a few days. However, soon reports of infiltration elsewhere along the LoC made it clear that the entire plan of attack was on a much bigger scale. India responded with Operation Vijay, a mobilisation of 200,000 Indian troops. However, because of the nature of the terrain, division and corps operations could not be mounted; the scale of most fighting was at the regimental or battalion level. In effect, two divisions of the Indian Army, numbering 20,000, along with several thousand from the Paramilitary forces of India and the air force were deployed in the conflict zone. the Indian Army moved into the region in full force. Soon, the intruders were found to be well entrenched and while artillery attacks had produced results in certain areas, more remote ones needed the help of the air force.
The Indian Air Force (IAF) was first approached to provide air support on 11 May with the use of helicopters. On 21 May a Canberra on a reconnaissance mission, flown by Sqn Ldr A Perumal and Sqn Ldr UK Jha, was hit by ground fire. The flight was however, recovered safely, and returned to base on one engine. On 25 May, the Cabinet Committee on Security authorized the IAF to mount attacks on the infiltrators without crossing the LoC. Initial indications from the government to the IAF was to operate only Attack helicopters. However, the Chief of Air Staff put forth the argument that in order to create a suitable environment for the helicopters, fighter action was required. On 26 May, the go-ahead was given and the IAF started it's strike role . Flying from the Indian airfields of Srinagar, Avantipur and Adampur, ground attack aircraft MiG-2ls, MiG-23s, MiG-27s, Jaguars and the Mirage 2000 struck insurgent positions.Of note, although the Mig-2l is built mainly for air interception with a secondary role of ground attack, it is capable of operating in restricted spaces which was of importance in the Kargil terrain.
The first strikes were launched on the 26th of May, when the Indian Air Force struck infiltrator positions with fighter aircraft and helicopter gunships.. The initial strikes saw Mig-27s carrying out offensive sorties, with Mig-21s and (later) Mig-29s providing fighter cover. Mi-17 gunships were also deployed in the Tololing sector.. Srinagar Airport was at this time closed to civilian air-traffic and dedicated to the Indian Air Force.
However, on 27 May, the first fatalities were suffered when a Mig 21 and a Mig 27 jets were lost over Batalik Sector to enemy action and mechanical failure. The following day, a Mi-17 was lost- with the loss of all four of the crew- when it was hit by three stingers while on an offensive sortie.. These losses forced the Indian Air Force to reassess it's strategy. The helicopters were immediately withdrawn from offensive roles as a measure against the man-portable missiles in possession of the infiltrators.
On 30 May, the Indian Air Force called into operation the Mirage 2000 which was deemed the best aircraft capable of optimum performance under the conditions of high-altitude seen in the zone of conflict. Armed initially with 250 kg "dumb" bombs, No.7 Squadron over three days, struck infiltrator positions in Muntho Dhalo, Tiger Hill and Point 4388 in the Drass Sector. The strikes on Muntho Dhalo on 17 June also destroyed logistics and re-supply capabilities of the infiltrators in the Batalik Sector. Through the last weeks of June, the Mirages, armed with LGBs as well as with "dumbs", repeatedly struck the heavily defended Tiger Hill. The first of these missions were observed by the (then) Chief of Air Staff, ACM AY Tipnis The choppers used were Mi-8 and the Mi-17. The transport planes were Avro, An-32 and IL-76. On May 27, the IAF had sent a MiG-27 on a photo reconnaissance mission over the Indian side of the Line of Control in Kashmir. Piloted by Flt Lt K Nachiketa, Indians claim he ejected from his MiG-27 after an engine flameout. Squadron Leader Ajay Ahuja, who was in his MiG-21 tried to trace the downed MiG despite a blatant threat in the form of enemy Anti-Aircraft Guns. Within minutes his plane was shot at by a Stinger shoulder fired missile. Having crashed, it is believed by Indian military that he survived the crash but was killed by Pakistan Army soldiers or irregulars in a shoot out. The body of Ahuja bore two bullet wounds as per the postmortem done by the Indian authorities. Flt Lt Nachiketa was later paraded on Pakistan TV, this prompted India to accuse Pakistan of violating the Geneva convention on the treatment of Prisoners of War.
The next day the air force lost an Mi-17 Helicopter to a shoulder fired missile near Tololing, killing the crew of four. This resulted in a change in strategy and technology. With the Israel providing around 100 Laser-guided bomb kits to the Indian Military, the air force chose to make maximum use of this and retaliated with regular sorties on Pakistani occupied bunkers. The aircraft operated at 10,000 feet AGL (30,000 feet above sea level), well out of MANPADs range, leading to a drop in the accuracy rate of the bombs. The low number of airstrips for take off and landing of the flights also constrained the efficiency of the attacks. Despite this, there were hundreds of sorties on the intruders with no further material or personnel casualties enabling a gradual takeover of the mountain posts by Indian troops. According to IAF the "air strikes against enemy supply camps and other targets yielded rich dividends."
By July all the remaining intruders had withdrawn and the operation was ended, being declared a success by the IAF in having achieved its primary objectives. However there has also been criticism of the methods initially used and the type of planes being unsuitable to the terrain that resulted in early losses. This is believed by many in the air force as coming as a wake up call to upgrade the aging fleet of craft to better enable them to fight in the mountainous region. But, in the context of the war and in light of the poor information available on the infiltrations, the Indian Air Force was able to coordinate well with the Army and ensured that most of the posts were retaken even before Pakistan decided to withdraw its remaining troops.