Isadore was born on 15 September 1916 in Mile End, London to Julius and Sarah nee Friedman. Julius and Sarah had ten children of which seven survived into adulthood. The family ran a building company and Isadore worked as a carpenter. In July 1940, Isadore married Sylvia Tobert in Hackney and enlisted a few months later.

Isadore was on board Beaufort X8925 which was practising low flying over the sea and torpedo attack tactics at 1430 hours. The pilot Sergeant Bell misjudged the aircraft height on a turn and the wing struck the water. The aircraft cartwheeled into the sea, and all on board were killed. The accident took place off Ayr, Scotland.

The crew members of X8925 were:

Sgt Merton John Bell, 402149
A/C Class I Kenneth Robert Ernest Dutton, 553765.
Sgt Leslie Gordon Staniland, 1375445.
A/C Class II Isadore Tankel.
Pilot Officer Allan Goodall Thompson.