P/O Sadler was in 611 & 92 Squadrons, RAF.
Herbert was a pre-war airman and was with 611 Squadron at Digby in early 1940.
On 2nd June he claimed a Bf 110 destroyed over Dunkirk.
On 5th September he was posted to 92 Squadron at Pembrey where, on 11th he claimed a Bf 110 destroyed and had a share in a Do-17 on 15th.
On 26th September, Herbert re-joined 611 Squadron, then operating from Tern Hill.

He was commissioned on 30th October.

On 5th February 1941. Herbert's Spitfire was severely damaged while on a sortie over the French coast. His engine was on fire, and he was rapidly losing height. It appears that he was unable to release himself from the cockpit, and the aircraft went on a steep dive into the sea. He was 24 years old.

Herbert was the son of Charles Thomas Sadler and Emma Frances Sadler, of Westcliff-on-Sea, Essex.

He is also remembered on Panel 34. Memorial: RUNNYMEDE MEMORIAL