Diana Rigg plays Becky's (Rachael Stirling) mother, and is in fact Rachael Stirling's mother in real life.
The plane that Peter (Daniel Donskoy)'s grandfather flew, the JU-88, was a twin-engined bomber that performed a variety of roles for the Luftwaffe in the Second World War. The JU-88 suffered higher losses than the other two bombers used in the Battle of Britain, the Dornier Do 17 and Heinkel He 111, despite having smaller numbers involved.
Andy (Mackenzie Crook) compares his childcare skills with those of Gina Ford. Gina Ford is a well-known and slightly controversial author of bestselling childcare books in the UK.
Second time that real life mother and daughter, Diana Rigg (Veronica) and Rachael Stirling (Becky), have played Mother and Daughter. The previous was in Doctor Who's "The Crimson Horror (2013)".