No. 17 Squadron then equipped with Bristol Bulldog Mk.IIs in October 1929, these would be kept up until August 1936. However, during the Abyssinian Crisis in 1935, the Squadron lost most of its Bulldogs as reinforcements for other squadrons moving to the Middle East and so had to fly Hawker Harts for a period. No. 17 Squadron were equipped with Gloster Gauntlets in August 1936. It was in recognition of these aircraft that the Squadron got its badge design, which was officially approved by Edward VIII in October 1936. The Squadron received its first monoplane, the Hawker Hurricane Mk.I, in June 1939. No. 17 Squadron flew defensive patrols from numerous bases in Britain, including RAF Debden and RAF Martlesham Heath, until the German attack on France in May 1940. Once the Phony War was over, fighter sweeps were then flown over the Netherlands, Belgium and French airfields to cover the retreat of allied troops. In June 1940, the Squadron moved to Brittany as the remnants of BEF and RAF units in France were evacuated, retiring to the Channel Islands for two days before returning to the UK. No. 17 Squadron flew over southern England throughout the Battle of Britain. The Squadron briefly upgraded to Hurricane Mk.IIas in February 1941 however they shortly reverted to Hurricane Mk.Is in April. No. 17 Squadron moved up to RAF Castletown in northern Scotland on 5 April for rest. In July 1941 the Squadron again upgraded its Hurricanes, this time to Mk.IIbs. On 11 November 1941, the Squadron sailed for the Far East where war broke out on 7 December. Diverted to Burma, it arrived in January 1942, as Japanese troops neared Rangoon. Defensive patrols were flown until the Rangoon airfields were overrun and No. 17 Squadron moved north, eventually being cut off from India while operating from Lashio. The surviving aircraft were flown out and the ground personnel made their way across Burma to the Indian border. By the end of May, the Squadron had re-assembled at Calcutta and in June received aircraft again for the defence of the area. In August 1942, No. 17 Squadron upgraded to Hurricane Mk.IIcs. Ground attack missions began in February 1943 and continued until August, when the Squadron moved to Ceylon. Supermarine Spitfire Mk.VIIIs began to arrive in March 1944 and were taken back to the Burma front in November to fly escort and ground attack missions. In June 1945, No. 17 Squadron upgraded to Spitfire Mk.XIVes.