Miss Shilling's Orifice [From the Wingspan archives]

"ttyymmnn" (ttyymmnn)
01/10/2018 at 12:35 • Filed to: wingspan, Planelopnik

Get your mind out of the gutter. It’s not what you think.

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Author’s Note: Please enjoy this article from the Wingspan archives as I work to catch up in the New Year.

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The !!!error: Indecipherable SUB-paragraph formatting!!! and !!!error: Indecipherable SUB-paragraph formatting!!! were the two principal RAF fighters of WWII, and both are revered for the important role they played in turning the tide of war in Europe. Both were powered but the mighty !!!error: Indecipherable SUB-paragraph formatting!!! engine, but early versions of the 12-cylinder powerplant had a nasty habit of losing power, or cutting out altogether, during high-G maneuvers or too much inverted flight. Unlike the fuel injected !!!error: Indecipherable SUB-paragraph formatting!!! engine of the !!!error: Indecipherable SUB-paragraph formatting!!! , the Merlin was fitted with an !!!error: Indecipherable SUB-paragraph formatting!!! (or carburettor, if you prefer the British spelling for a British engine). During certain maneuvers, such as a hard pitch down of the nose, the fuel was forced upwards to the top of the float chamber of the carburetor, flooding the engine. This led to a loss of power, or a complete cutoff of the engine, which is really not something that you want to have happen in the middle of a pitched dogfight.

A permanent solution was found by using a Bendix or Rolls-Royce !!!error: Indecipherable SUB-paragraph formatting!!! , but until that unit could be developed, a stopgap solution was discovered by !!!error: Indecipherable SUB-paragraph formatting!!! , an engineer working at the Royal Aircraft Establishment at Farnborough. She devised a flow restrictor (officially called the R.A.E. Restrictor, but nicknamed “Miss Shilling’s Orifice,” the “Tilly Orifice, and “Tilly’s Diaphragm”) which limited fuel flow to the maximum the engine could use during a dogfight and, along with a revised carburetor needle, it solved the fuel flooding problem until the permanent fix could be found. Miss Shilling toured England with a group of mechanics, retrofitting the engines of the RAF fighters, with priority given to front line units. By the end of 1941, all the Merlins had been modified and were back in the fight, much to the relief of the beleaguered pilots.

Tilly Shilling was born in 1909, earned degrees in both electrical and mechanical engineering, and worked for the Royal Aircraft Establishment from 1936 to 1969. She raced motorcycles in the 1930s, and earned the Gold Star for lapping the circuit at Brooklands at an average speed of 106 mph. And she refused to marry her RAF bomber pilot husband George until he completed the same feat. After the war, the pair kept their own shop for tuning racing cars, and both raced with modest success. Tilly also landed her expertise to Dan Gurney in 1967 when he needed help overcoming problems with overheating in his Eagle Mk1 F1 car. Shilling died in 1990 at age 81.

Beatrice Shilling with her Norton motorcycle

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Connecting Flights

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If you enjoyed this post, please join in the conversation and let me know. For more posts about aviation, aviation history and aircraft oddities, head over to !!!error: Indecipherable SUB-paragraph formatting!!! .

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DISCUSSION (11)

Party-vi > ttyymmnn
01/10/2018 at 12:57

“she refused to marry her RAF bomber pilot husband George until he completed the same feat.”

BAMF right here.

ttyymmnn > Party-vi
01/10/2018 at 13:12

Indeed.

Ready for an adventure! > Party-vi
01/10/2018 at 13:14

BAMF? Bad Arse Man fricker?

vondon302 > ttyymmnn
01/10/2018 at 13:41

106 mph on a 1930s motorcycle? Bad ass isn’t strong enough to describe her. Just thinking about the tires in 1930 makes me squeamish.

MoCamino > vondon302
01/10/2018 at 13:57

The motorcycle skillz are impressive enough, don’t get me wrong. But being smart enough to be taken seriously as a female engineer in the 1940's? THAT’S impressive. It’s hard enough today due to the still rampant sexism. But back then? Wow. Smart lady. Way smarter than me.

vondon302 > MoCamino
01/10/2018 at 14:08

Good point!

AfromanGTO > ttyymmnn
01/10/2018 at 14:35

Ok they should do a movie about her life. Not a cheesy lifetime one either a good one. Maybe get Ron Howard to do it, because he did a good job with Rush.

ttyymmnn > AfromanGTO
01/10/2018 at 14:36

Yeah, she does kind of resemble Ron Howard.

That would be a cool movie, though.

AuthiCooper1300 > ttyymmnn
01/10/2018 at 17:47

Great article as usual!

You may also like to read about this lady (who, unfortunately, worked for the other side - and yes, she was related, by marriage, to a rather famous person):

http://company.airbus.com/company/heritage/female-pioneers/Melitta-Von-Stauffenberg.html

ttyymmnn > AuthiCooper1300
01/10/2018 at 18:10

Thanks! And I’ll be sure to hit that link. I try very hard to highlight women in aviation, since they remain underrepresented and under appreciated.

AuthiCooper1300 > ttyymmnn
01/10/2018 at 18:21

You are welcome! May I suggest Sturmovik’s female pilots? (Now that I think about it it is quite likely you treated the subject already.)

I am racking my brains trying to remember where I saw a picture of Shilling in a late 60s/early 70s single seater, maybe a Formula Ford or a Formula 500 or something. Something to do with a hillclimb, maybe? Some lady, certainly.