Did you know that a device with a very naughty name saved many British pilots?

Spitfires going into a dive
(Photo: Imperial War Museums)

The Hawker Hurricane and the Supermarine Spitfire were the Royal Air Force’s premier interceptors during the Battle of Britain, but they had a serious design flaw. When a plane goes into inverted flight or suddenly dips its nose down, such as when going into a dive to pursue (or escape) an enemy, it experiences what’s called a “negative G force.” Imagine a small loose object in the cockpit: when you go into a dive, it suddenly shoots “up” into the cockpit’s roof. Unfortunately, the same thing kept happening to the fuel inside the planes: a dive would force the fuel in the carburetor to momentarily stop flowing into the engine and instead flow back toward the top of the carburetor’s float chamber. This first caused a loss of power, then the engine would cut out completely when the now overly rich fuel mixture started to flow again and drowned the supercharger.

Beatrice Shilling
(Photo: Unknown photographer)

The woman to the rescue was Beatrice “Tilly” Shilling, an aircraft engineer and avid motorist. Shilling invented a simple device, essentially a brass thimble with a hole in it, that could easily be fitted into already produced aircraft and would regulate fuel flow during such perilous moments. The device was officially named R A E Restrictor, but gained immediate popularity with the pilots under the rather inappropriate nickname “Miss Shilling’s orifice.”

Battle of the Bulge promotion

Pay in full and get 15% off until January 25

An American soldier in an attack on German forces in December 1944
(Photo: U.S. Army, Tony Vaccaro)

We will start 2023 with a promotion in remembrance to the men who fought in the Battle of the Bulge. In the current four-week promotion period you can get a 15% discount on our select tours by booking and paying full by January 25, 2023. Note that this offer applies only in case of new bookings, and it cannot be combined with other special promotions. The offer excludes those three tours in 2024 which include the 80th anniversary D-Day commemorations in Normandy. If you have any questions related to this promotion or our tours, feel free to contact our travel consultants.

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