David was born on 3 June 1912 in in Mile End Old Town, London to Polish born parents Joseph and Hetty née Pearl. David had two older sisters and two brothers, Samuel and Philip who both served in the RAF as pilots. Samuel was tragically killed eight weeks before David serving in 83 Squadron.

David worked as a fur trader and was a member of the Civil Air Guard. He obtained his private pilots licence at Yapton in 1937. He married Phyllis Hockman in 1939 in Hackney and the Register shows them living at 10 Durley Road, Hackney where he is listed as an aircraftman 2nd class based at Uxbridge. They were only married for two years when Phyllis died aged twenty seven on 7 November 1941 just six months before he was killed. Her obituary in the Jewish Chronicle states that she passed way with her newly born baby daughter.

An article in the Jewish Chronicle featured the Block brothers:
Three brothers with ‘Wings’
‘What must be an unusual distinction, not only among Jewish families, but also in the country in general, is that held by the three brothers’ Block, who have all gained their ‘wings’ in the Royal Air Force. Two of them David (28) and Philip, the youngest are sergeant pilots, and the other, Samuel (34), is a sergeant air gunner. They are the sons of Mr. and Mrs. J. Block of Highbury, London, but are now living in Manchester. Both Sam and Phil were keen members of the Jewish Lad’s Brigade; Sam is a good boxer, and Phil excels at football (he was secretary of a Highbury football club). Dave, always an enthusiast for flying, was in the Civil Air Guard’.

David was the 2nd Pilot and flight engineer on Manchester L7429 which departed RAF Scampton on a night operation to Cologne. The aircraft was lost without trace. All the crew are commemorated on the Runnymede Memorial.

Pilot, Plt Off John Philip Carter.
Pilot, Flt/Sgt David Block.
Nav, Sgt George Charles Haynes.
W/Op A/G, Sgt Lawrence John Yeates.
A/G, Sgt John Cook Ramsey.
A/G, Sgt Arnold Gregory Welch RAAF.
A/G, Sgt Maurice Samuel Ash.