Many of the pilots assigned the Buffalo lacked adequate training and experience in the type. A total of 20 of the original 169 Buffalos were lost in training accidents during 1941. By December 1941, approximately 150 Buffalo B-339E aircraft made up the bulk of the British fighter defenses of Burma, Malaya and Singapore. The two RAAF, two RAF, and one RNZAF squadrons, during December 1941 – January 1942, were beset with numerous problems, including poorly built and ill-equipped aircraft. Aviation historian Dan Ford characterized it as, "The performance... was pathetic." Inadequate spare parts and support staff, airfields that were difficult to defend against air attack, lack of a clear and coherent command structure, a Japanese spy in the Army air liaison staff, antagonism between RAF and RAAF squadrons and personnel, and inexperienced pilots lacking appropriate training would lead to disaster. Although the Mk I had .50-inch guns, many aircraft were equipped with .303 Browning mounts and electric firing solenoids, which tended to fail in service.