which airlines was he a part of?
Trans Australia Airlines (TAA).
Lester Brain
Seeing little prospect for advancement at Qantas once the war had ended, Brain left to join the fledgling government-owned domestic carrier Trans Australia Airlines (TAA) in June 1946. 
who was lester brain? He was a pioneer Australian aviator and airline executive. where was he born? Forbes, New South Wales. did he take part in any war? Yes, World War II. what role did he play in it? He coordinated his airline's support for the Australian military.
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Lester Brain [SEP] Introduction
He earned a King's Commendation for his rescue efforts during an air raid on Broome, Western Australia, in 1942, and was promoted to wing commander in 1944. Seeing little prospect for advancement at Qantas once the war had ended, Brain left to join the fledgling government-owned domestic carrier Trans Australia Airlines (TAA) in June 1946. Appointed its first general manager, he swiftly built up the organisation to the stage where it could commence scheduled operations later in the year. By the time he resigned in March 1955, TAA was firmly established as one half of the Commonwealth government's two-airline system.