Hazel Hill

Hazel Bertha Hill (21 July 1920 – 28 September 2010) was a British Child Psychiatrist, probably best known for her contribution in changing an Air Ministry specification of firepower to be carried by new fighter aircraft before the Second World War.^[1][2][3][4]

Early life

Hill was born in London to Frederick William Hill and his wife Bertha (née Underwood).

She was only 13 when she helped her father calculate how many guns the new generation of fighter aircraft would need to bring down enemy aircraft.^[1] The pair used calculating machines, which were rudimentary computers, at the kitchen table of their London home.^[2] The new aircraft was to have four guns which fired 1,200 rounds per minute and many thought that this would be sufficient. Her father was not so sure. In June and July 1934 they worked at night to create the evidence that her father's boss needed to justify making a large change in the design. They calculated that 256 bullets in two seconds would be necessary to bring down an enemy bomber at the increased speeds of the new aircraft, and for this eight guns were required.^[3]

Hazel's son, Robin, said he thinks his mother enjoyed maths because she was partially

The RAF publicly acknowledged Hill's important role in a BBC documentary.[4] Group Captain James Beldon said: "What a great inspiration to young people today, and young girls in particular, who can look upon someone like Hazel in the 1930s making such an important contribution to our later success in the Battle of Britain, which was vital to this country's survival."

Later life

After school, Hill studied

She died, age 90, in 2010.[4]^[5]

References