Posted to England in June 1943, Balmer took command of No. 467 Squadron RAAF, flying Avro Lancasters in the air war over Europe. He led his unit through the Battle of Berlin from November 1943 to March 1944. In April he was awarded the Distinguished Flying Cross, and the following month promoted to temporary group captain. Days later, on the night of 11/12 May, the last scheduled operation of his tour as No. 467 Squadron's commanding officer, Balmer failed to return from a mission over Belgium. Initially posted as missing, his plane was later confirmed to have been shot down, and all of the crew killed. Balmer was buried outside Brussels.