It’s summer, 1940, the height of the Battle of Britain. After being jumped by a German fighter you’ve somehow managed to outturn him and get on his six. Your thumb moves to the firing button and you press it down hard.
Seeing your bullets land on the enemy fuselage, you expect it to catch fire or begin to smoke. Nothing happens, because your own fighter is only armed with four measly machine guns.
This is what nearly happened, but luckily six years earlier a 13-year-old girl managed to complete a very important homework assignment.
This is how Hazel Hill helped win the Battle of Britain.
Background
Now, if you are a student of the RAF’s fight against the Luftwaffe in 1940, you know that the Supermarine Spitfire, and my personal favourite, the Hawker Hurricane were armed with 8 .303 browning machine guns.
If you’ve spent any time flying the latest combat flight simulators, you know that even 8 .303s don’t do a great deal of damage to a heavily armoured German fighter. In fact, some variants of the Hurricane even had an additional four machine guns fitted to up its firepower. Imagine trying to down enemy bombers and fighters with just six .303s, or even four. And god, forbid, two!
Well, that so nearly happened.
If we go back to 1934, Britain and the rest of the world were just waking up to the threat coming out of Germany. The previous year, Adolf Hitler had been appointed chancellor after his party had won several electoral votes.
Despite the overall policy of appeasement which would develop up until the invasion of Poland in 1939, the British Air Ministry began to slowly wake up.
How were aircraft chosen and designed?
When the Britain government wanted to upgrade its air force, it would issue a specification through the air ministry. Then the various aircraft companies would scramble to design a new plane to meet it. The best ones would win and perhaps get a contract to produce the aircraft.
It was extremely rare for an aircraft company to come up with its own design and then push it onto the air ministry. But it did happen, and that’s part of our story later.
In 1934, the frontline fighter in the RAF was the Hawker Fury II which carried just two machine guns and had a top speed of 223 miles per hour at 15,000 feet. Basically very little had changed in the two decades since the first world war had ended.
That very same year the Bayerische Flugzeugwerke, or Bavarian Aircraft company to us with a terrible accent, designed an aircraft known to the world as the 109.
The first prototype flew in October 1935— ironically powered by a British Rolls-Royce engine. The production Bf 109B was armed with four 7.92-mm machine guns, which would have decimated a Hawker Fury. Later variants even boasted a cannon firing through the nose, which was even more devastating.
The same year that the BF 109 was designed, the Air Ministry, in answer to specification F.7/30, accepted the prototype from the Gloster company. aircraft we all know as the Gloster Gladiator. It would go into production in 1935. Armed with four .303 machine guns, two of which were synchronized through the nose, this bi-plane was essentially Britain’s best answer to the new German fighter.
But all of that was going to change.
Based on the calculations done by a father and his young daughter, the Air ministry would come to understand that a modern fighter would need no fewer than 8 .303 machine guns to get the job done.
How was Captain Frederick William Hill involved?
In 1931, Sir Hugh Dowding started the ball rolling by asking for a report on the accuracy that could be achieved by the faster fighters of the time. Over three years, air trials generated a huge amount of data. Someone had to go through and compile all of this and reach some sort of conclusion. That person would be Captain Frederick William Hill.
Often working at his kitchen table late into the night with a primitive calculating machine, Hill began to see a worrying picture. The two machine guns of the contemporary Furies would fall far short of what was needed, and so would the armament of the Gladiator.
The aim was to get as much lead onto a target in as short a time as possible. With ever-increasing closing speeds and the notion, false as it turned out, that dog fighting was outdated, fighter would only get one pass to down the enemy.
It was also becoming clear to some that a new conflict was fast approaching.
Suddenly, Hill was under pressure to finish his work and make sure that the next specification given by the Air Ministry could rapidly push the right type of fighter into production.
And so, Hill engaged the help of his 13-year-old daughter who, so the story goes, stayed up with her father and helped calculate Britain’s only defense against invasion six years later.
Hazel Hill’s contribution
Hazel’s son Robin, said he thinks his mother enjoyed maths because she was partially dyslexic and had trouble with spelling. This led to some teachers thinking she was being naughty as she was obviously intelligent. “I think when she did mathematics, she had none of these problems, which is why it appealed to her so much,” Robin said. I can relate to that as I’m also dyslexic, but unfortunately, I’m pretty bad at mathematics too!
And Hazel Hill did genuinely help her father, who probably would not have been able to finish his work in time for an important meeting in July 1934.
At the time, a new specification was being developed which hypothesized that a new fighter would need four guns that fired 1,200 bullets a minute. This was thought to be enough.
Hazel’s father was not so sure. After their calculations, they realized that 256 bullets would be required in a two-second burst to bring down an enemy bomber at the increased speeds of the new aircraft.
Four .303 machine guns, such as the browning used in later hurricanes and spitfires, with a rate of fire of just 1,150 rounds per minute, would only give you 150 bullets on target from four guns. The new fighters would need double that.
When Captain Hill handed his report to his boss the Assistant Director of Armament Research and Development, Claude Hilton Keith he acknowledged the vital help his daughter had given him. Something Keith would mention in his own memoirs.
Armed with the new findings, Keith was able to discuss the matter with Air Commodore Tedder and the need for an 8-gun-fighter was slowly accepted.
The very next Air Ministry specification, F.5/34, reflected the need for a replacement for the Hawker Fury which could also boast 8 .303 machine guns. This was directly what led to the development of the Hawker Hurricane. The Supermarine Spitfire, which was personally pushed by the company, also followed the same basic specification. Without which, Britain would not have survived the Battle of Britain.
Hazel Hill would go on to join the Royal Army Medical Corps after graduating from university in London in 1943. In later life, she became a GP, and married one of the soldiers she helped heal during the war.
