Beatrice Shilling fixed the stall-prone Rolls-Royce Merlin engines with a simple disc to limit fuel flow, fondly known as Miss Shilling’s orifice.
The Battle of Britain was one of the great turning points of WWII. The air battle — fought largely over Southern England — was a vital victory for the Allies. From a morale point of view, it proved that the German war machine was not invincible. From a strategic point of view, the Battle of Britain put paid to Hitler’s plans to invade Britain. At the heart of this air battle were two legendary British fighter planes — the iconic Spitfire and the often-underappreciated Hurricane, both of which were powered by the equally legendary Rolls-Royce Merlin engine.
It’s this engine that’s at the center of this story. While it certainly earned its legendary status, it wasn’t without flaws. Unlike the fuel-injected engines used in German fighters of the time, the Merlin used a carburetor. This carburetor had the unfortunate tendency to flood and stall the engine when an aircraft entered a negative g-force dive, which was often the case in dogfights. Despite this drawback, the RAF defeated the Luftwaffe, and the Battle of Britain was won. However, it was obvious that the Merlin engine problem needed to be addressed. Enter Beatrice „Tilly“ Shilling and her genius device. Officially, the device was called the RAE restrictor, but it became more fondly known as Miss Shilling’s orifice. Beatrice Shilling’s solution to the stalling issue was a simple metal disc with a hole in it.
