On 4 April 1942, Squadron Leader Leonard J. Birchall led Royal Canadian Air Force (RCAF) Squadron 413 on a reconnaissance flight to an observation position 250 miles (400 kilometres) south of Ceylon. Birchall's squadron of Catalina "flying boats" had just completed a tour of patrol duty over the convoy route from Britain to the Soviet Union known as the "Murmansk run."
During the patrol, RCAF Squadron 413 did not encounter any vessels. As the squadron was returning to the British naval base in Ceylon, Squadron Leader Birchall sighted a small dot on the southern horizon. Birchall changed course, while the rest of his squadron turned for home. As his plane approached the target, he was able to identify it as a Japanese task force. Japanese aircraft spotted the RCAF Catalina as it approached the fleet. Despite heavy enemy fire from anti-aircraft guns and Japanese fighter planes, Birchall conducted a low-level flight to identify the Japanese ships in the task force. It consisted of five aircraft carriers and four battleships supported by several cruisers, destroyers, and troopships.
Squadron Leader Birchall immediately began sending coded transmissions to the British base in Ceylon. According to regulations, units were to send each transmission three times. Birchall was in the middle of the third coded transmission when anti-aircraft fire destroyed the radio and seriously damaged his Catalina. After crash landing his plane in the ocean, Birchall and his crew were taken prisoner by the Japanese.
The Japanese brutally interrogated Birchall and his crew, who insisted that they had not had time to send any transmissions. When questioned about the strength of British forces in Ceylon, Birchall told his captors that he had no knowledge of the British defences because his squadron had only been posted in Ceylon for a day. Birchall and his crew were taken aboard the Japanese Imperial Navy carrier Akagi and were later transported to Japan. As a result of Birchall's heroic actions, the British were able to repulse the Japanese assault. The Japanese suffered heavy losses, losing 50 fighters and 50 bombers in the attack before retreating.
In captivity, Birchall proved to be a champion of prisoner's rights in the brutal conditions of the Japanese prisoner-of-war camps. He repeatedly endured savage beatings by Japanese guards when he intervened to protect prisoners from torture or when they were denied medical care.
Squadron Leader Birchall was awarded the Distinguished Flying Cross for his actions, and was later given the Order of the British Empire for his leadership and courage while in captivity. Prime Minister Sir Winston Churchill declared that Birchall had made "one of the most important single contributions to victory."