Not a pilot, but Plt Off Bernard Green was 52 when he was shot down in a 44 Sqn Hampden during WW2. He fought in the First World War, was wounded twice, and ended the War as a major in the Machine Gun Corps.
He joined the RAF at the beginning of WW2 as a plt off and became an air gunner due to his MG experience. His 44 Sqn Hampden was shot down on his first mission, and "Pop" became a POW. He was sent to Stalag Luft III and took part in the Great Escape although he believed that his age contributed to his escape from execution by the Gestapo after he was recaptured.
His biography is an interesting read...
https://www.amazon.co.uk/Great-War-E...o+Great+Escape