on 18 January. Several Dutch pilots—including Jacob van Helsdingen and August Deibel—responded to a number of air raids over Singapore while stationed at Kallang Airport. They claimed a total of six aircraft, particularly the Nakajima Ki-27 Nate, which fared poorly in Malaya. On 3 January 1942, 51 disassembled Hurricane Mk IIBs arrived in Singapore along with 24 pilots (many of whom were veterans of the Battle of Britain) who had been transferred to there with the intention of forming the nucleus of five squadrons. The 151st Maintenance unit assembled the 51 Hurricanes within two days and of these, 21 were ready for operational service within three days. The Hurricanes were fitted with bulky 'Vokes' dust filters under the nose and were armed with 12, rather than eight, machine guns. The additional weight and drag made them slow to climb and unwieldy to maneuver at altitude, although they were more effective bomber killers. The recently arrived pilots were formed into 232 Squadron. In addition, 488 (NZ) Squadron, a Buffalo squadron, converted to Hurricanes. On 18 January, the two squadrons formed the basis of 226 Group. The following day 453 squadron provided an escort of eight aircraft for five Wirraways and four NEI Glenn Martin bombers, attacking Japanese troops on the Maur River. All the Martins and one of the Wirraways were lost. No 243 Squadron RAF, equipped with Buffalo fighters, was disbanded on 21 January and 232 Squadron became operational on 22 January, the same day the Genzan Air Group attacked Kallang Airport. 232 Squadron thus had the first losses and victories for the Hurricane in Southeast Asia that day. Most of the bombers were moved to Sumatra midway through January. Aircraft from 36, 62, and 100 Squadrons unsuccessfully attacked the Japanese invasion fleet at Endau on 26 January, suffering heavy losses. The surviving aircraft were evacuated to Sumatra on 31 January. In mid-January, the three Sentai of the 5th Air Corps returned to Thailand to participate in the Burma Campaign and the 3rd Air Corps turned its attention to the Netherlands East Indies. In the end, more than 60 Brewster aircraft were shot down in combat, 40 destroyed on the ground, and approximately 20 more destroyed in accidents. Only about 20 Buffalos survived to reach India or the Dutch East Indies. The last airworthy Buffalo in Singapore flew out on 10 February, five days before the island fell. The RAAF