P/O Finnie joined 54 Squadron at Rochford on 8th July 1940.

On 24th July, Archie was convoy patrol over the Channel off Dover when his aircraft sustained damage while attacking Do 17s. He force-landed his Spitfire (P9389) at Great Bainden Farm, Mayfield, and later returned to Rochford.

The next day, while patrolling over a convoy near Dover, Archie was shot down by a Bf 109 at 18:10hrs. His Spitfire I (R6816) crashed at Kingsdown, Kent, and Archie was killed. He was 24 years old.

Archibald Finnie is buried in Margate Cemetery, Kent.