In China Gladiators were used extensively before the start of 1940 by the 28th, 29th and 32nd squadrons of the 3rd Group. Chinese aviators considered the Gladiator an excellent fighter in its class but pilots soon found it increasingly difficult to hold their own against the modern A5M and because of a lack of spare parts due to an arms embargo, the surviving Gladiators were mostly relegated to training.[22] When newer Japanese aircraft such as the Mitsubishi A6M entered the theatre, the Gladiators' days were numbered. American-born Chinese pilot John "Buffalo" Wong, the first Gladiator flying ace and first American fighter ace of the Second World War, was eventually shot down in combat with A6M Zeros on 14 March 1941 and died two days later from his injuries.[23] He and Arthur Chin were among a group of 15 Chinese Americans, who formed the original group of American volunteer combat aviators in China.[24]