United Kingdom unable to reinforce defence of Singapore with aircraft according to the U.S. Joint Intelligence Committee. Daily summary dated 5 January 1942

An item referred to the Japanese military attache at Ankara, Turkey who informed his Italian an German colleagues that England won’t be able to reinforce Singapore with planes from India while they lost the control over the north-south communications and reinforcing while using aircraft carriers was impossible due to the threat of Japanese torpedo planes. The attache claimed that the pilots of the torpedo planes were all such fanatical that a loss of 50% in major endeavors was inspected.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 26 dated 5 January 1942