The real test of IAF airlift capability came in October 1962, when open conflict erupted on the Sino-Indian border. During the period 20 October to 20 November, pressure on the Service`s transport and helicopter units were intense, troops and supplies having to be flown to the support of the border posts almost around the clock and at extreme altitudes. The helicopters had to continuously run the gauntlet of Chinese small arms and anti-aircraft fire, while operating to the complicated helipads in the mountains. Many notable feats were performed by the IAF during this conflict, including the operation of C-119Gs from airstrips 17,000 ft (5180m) above sea level in the Karakoram Himalayas, and the air-lifting by An-12Bs of two troops of AMX-13 light tanks to Chushul, in Ladakh, where the small airstrip was 15,000 feet above sea level.
The IAF was expanding rapidly, its workers strength of 28,000 officers and men at the time of the Sino-Indian conflict increasing by some two-thirds by the end of 1964, but the manpower requirements of the 33-squadron force had still to be implemented fully when the scheme was overtaken by even more determined expansion to a 45-squadron force which was sanctioned by the Government in October 1962, this calling for the raising of IAF staff strength to some 100,000 by the early seventies.