On 1 February, No.1 Squadron arrived in Burma with its Lysanders, flying tactical recce missions from Toungoo before transferring to Mingaladon with a flight deployed at Lashio. I A F personnel were soon hanging pairs of 250-lb. bombs on each of their Lysanders and with these, flew low-level unescorted missions against the principal Japanese air bases at Mae-Haungsaun, Cheingmai and Chiangrai in Thailand. However, the Japanese advance was relentless and with the final evacuation of Burma, No.1 Squadron personnel were flown to India, where at Risalpur in June 1942, the unit began conversion to the Hurricane IIB fighter. No.2 Squadron had also equipped with Lysanders by the end of 1941, being confined to anti-invasion exercises until, in September 1942, it emulated the IAF's premier unit by converting to Hurricanes. The third IAF unit to operate the Lysander was No.4 Squadron, formed with four aircraft on16 February 1942. This squadron was to continue to operate theWestlandaircraft until it, too was re-equipped with the Hurricane in June 1943. Six months earlier, No.6 Squadron was raised with personnel from Nos 1 and 2 flights, being Hurricane-equipped from the outset. Between March and December 1942, 10 aircrew schools were opened in India, and the first Harvard Is and IIs were delivered to No. 1 Flying Training School at Ambala, this school having been established to provide basic and advanced training for IAF pilots over a four-and-half month course. By theend of that year, however,or a decade after the IAF's creation and three years into World War II, the Service could muster just five squadrons. The coastal defence flights had now been disbanded and most personnel of Nos.3 and 6 Flights were combined with regular IAF personnel to form No. 7 Squadron which was equipped with the U:S. - built Vengeance 1 dive bomber in mid-February 1943. No. 8 Squadron was raised meanwhile, on 1 December 1942, absorbing the remaining coastal defence flight personnel, and also issued with the Vengeance, to achieve operational status on 25June 1943.
The Vengeance suffered numerous defects and teething troubles, necessitating temporary withdrawal from the two IAF squadrons, but the problems were eventually mitigated if not eradicated, and No. 8 Sqn flew its first operational Vengeance sorties against Japanese targets from Double Moorings, Chittagong, on 15 December 1943, No. 7 Squadron, which had flown its Vengeances on some missions against dissident tribesmen in North Waziristan, started operations in the Arakan from an airstrip at Uderbund, near Kumbigram, where it arrived on 12 March 1944, the two squadrons converting to Vengeance IIIs during the course of operations andboth flying with considerable distinction.No. 7 Squadron discarded its dive bombers in favour of Hurricane IIs for the tactical-reconnaissance role in November 1944, No. 8 Squadron becoming the first to convert onto the Spitfire VIII during the previous month and commencing operations on3 January 1945 in the Kangaw area.
Both Nos 9 and 10 Squadrons were raised on Hurricanes in the early months of 1944, and thus, by the end of the year, the operational element of the IAF had risen to nine squadrons, with Nos. 1,2,3,4,6,7,9 and 10on Hurricanes and No.8 on Spitfires. Five of the
Hurricane-equipped squadrons played a major role in the Arakan offensive which began in December 1944, disrupting the enemy's lines of communication and constantly harrying the Japanese forces until victory was achieved with the re-occupation ofRangoon on 3 May 1945. In that month, No. 4 Squadron became the second IAF Spitfire unit when it re-equipped with the Mk VIII version of this fighter, and No. 9 followed suit to complete conversion byJuly, by which time No. 10 had begun conversion, and the Hurricane, backbone of the IAF combat element for much of the war, was rapidly phased out.
During the war years, the steady expansion of the IAF had placed all emphasis on army co-operation and tactical reconnaissance; it had continued to fly ageing equipment such as the Hurricane when such aircraft as the Thunderbolt and Mosquito were being inducted in large numbers by other Allied forces in the theatre and it had, in consequence, suffered a sense of equipment inferiority. Nevertheless, assigned the least glamorous of tasks and flying obsolescent equipment, the Service established traditions of courage and efficiency second to none; its personnel had been awarded 22 Distinguished Flying Crosses and a host of other decorations, and in recognition of its achievements, the Service had been honoured by bestowal of the prefix "Royal" on its title in March 1945.
The stimulus provided by the Second World War had raised RIAF personnel strength to 28,500 including some 1,600 officers, by the time hostilities terminated. In August 1945, No. 4 Squadron was designated a component unit of the British
Commonwealth Occupation Forces in Japan, exchanging its Spitfire Vllls for Mk XlVs in October and arriving in Japan aboard HMS vengence on 23 April 1946. Meanwhile, from late 1945, the remaining Hurricane-equipped RIAF fighter squadrons converted to the Spitfire at Kohat, Samungli and Risalpur and by mid-1946 the entire RIAF fighter force was Spitfire-equipped. The year 1946 also saw the establishment of the first RIAF transport unit, No.12 Squadron which had first been raised on Spitfires at Kohat in December 1945 and received C-47 Dakotas in Panagarh in late 1946. A decision had also been taken to re-equip the fighter squadrons with the Tempest II, and implementation of this decision began during the autumn of 1946, No. 3 Squadron at Kolar becoming the first to re-equip, followed by No.10 Squadron later in 1946.
Personnel strength had meanwhile been virtually halved to some 14,000 officers and men in the post-war rundown, but the British authorities had made their own assessment of India's post-war defence needs. As of October 1946, they envisaged expansion of the existing ten RIAF squadrons into a balanced force of twenty fighter, bomber and transport squadrons. Owing to the rapidly changing political situation, however, definitive decisions concerning Indian defence were, in the event, to be left to the emerging Government of Independent India. No. 4 Squadron converted to the Tempest 11 upon its return to India from Japan and Nos.7 and 8 Squadrons also relinquished their Spitfires for the more efficacious Tempest fighter during the summer of 1947. Nos. 1 and 9 Squadrons, too, received Tempest lls at this time, but on 15 August 1947, and with the division of both India and its armed forces, these units stood down and their equipment was transferred to the newly created Royal Pakistan Air Force. Thus, the principal components of the RIAF at partition were Nos. 3,4,7,8 and 10 Squadrons with Tempest us, No. 2 Squadron with Spitfires and No. 12 Squadron with C-47s, plus No. 1 Air Observation Flight, the establishment of which with AOP Auster 4s, 5s, and 6s, coincided with independence. No. 6 Squadron, which had been in process of converting from Spitfires to C-47s at Drigh Road, had been stood down and its transports transferred to Pakistan.
The RIAF had lost many permanent bases and other establishments as a result of the division of the country, but was to have virtually no breathing space in which to recover from the surgery that had accompanied partition before the Service was to find itself once more firing its guns in earnest. On 27 October 1947, No.12 Sqn was to initiate the remarkable feat of air-lifting the Ist Sikhs from Palam onto the rough and dustySrinagar airstrip without planning or reconnaissance as the initial Indian response to the sizeable insurgent forces that were pouring across the border into Jammu and Kashmir. On 30 October, the first Spitfires from the Advanced Flying School at Ambala reachedSrinagar and were soon engaged in strafing the raiders beyond Pattan. Within a week, the Tempests of No. 7 Squadron were playing a decisive role in the battle of Shelatang which halted the forward momentum of the insurgents.
The fighting was to continue for 15 months, with heavy RIAF involvement throughout, a ceasefire eventually coming into force on 1 January 1949, but despite being continuously on an operational footing throughout this period, the reorganisation and modernisation of the Service continued unabated. The Combined Services Headquarters had meanwhile been separated for command purposes and Air Headquarters established inNew Delhi This included the Operational and Training Commands, No. 1 Operational Group having been formed to supervise all RIAF units and their support elements engaged in the campaign in Jammu and Kashmir.