Flickr User Tony Webster // CC BY 2.0
Flickr User Tony Webster // CC BY 2.0

How Do Power Outlets On An Airplane Stay Grounded?

Flickr User Tony Webster // CC BY 2.0
Flickr User Tony Webster // CC BY 2.0

Airlines know we can’t go a few hours without our precious electronic devices, which is why many airplanes feature power outlets to help people stay plugged-in. Being able to charge your laptop like you would at home is a perk, but how is the electrical socket grounded when you’re 35,000 feet above the Earth?

A plug's grounding pin and the corresponding hole you see on an outlet you have at home is there for safety. In case of a lightning strike or power surge, that prong is connected to the Earth, which gives the excess electrical current somewhere to go besides an appliance (or through you while you are holding said appliance). Wiring airplane power outlets to the Earth below is obviously out of the question, so something else has to take the ground's place as a conductor to dissipate electric current. Luckily, an aircraft’s metal frame is perfectly suited for the job.

“If the third pin (‘ground’) on the receptacle were connected at all, it would be to the metallic structure of the airplane,” electrical engineer Roger L. Boyell tells mental_floss over email.

Grounding, after all, is just a term. As long as it can complete its circuit, electricity couldn’t care less about where the Earth is.

“Grounding on the airframe is analogous to grounding to the Earth,” turbomachinery expert Steven B. Kushnick tells mental_floss, also over email. To electricity, the airplane’s metal frame is a much more desirable conductor than a person, and any time there is stray or excess current, it will always take the easiest path.

Kushnick explains it thusly:

If you had one hand on the stainless steel sink in the lavatory (ground); and one hand on, perhaps, an electric razor that is plugged in and properly wired with a ground-prong, then stray electric currents would have no ‘desire’ to enter your razor-holding hand to get to your sink-touching hand (and shock you in the process) because the stray currents have a shorter circuit to travel: through the ground-prong to ground (airframe).

This remains true even in the event of lightning strikes. “Modern airplanes are frequently hit by lightning,” Boyell says. “Their skin is made electrically conductive to pass the current, much like through a wire, with no effect.” At most, this could “leak through to induce an electromagnetic field inside the airplane,” Boyell says, adding that it “could momentarily disrupt electronic instruments.” Even still, “an electrical device will be unaffected by whether it is plugged into a power outlet on the airplane or not.”

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The Secret to a More Pleasant Flight? Urinals
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Even if you can deal with the lack of legroom, privacy, and decent meal options on airplanes, your patience may start to wear thin when it comes time to pee. Being stuck waiting in long bathroom lines on planes may feel like one of life's unavoidable annoyances, but according to WIRED, there's a way to make the experience more tolerable. The secret involves urinals and a bit of math.

At last month's Crystal Cabin Awards, a competition that recognizes innovation in aircraft interiors, Zodiac Aerospace introduced the Durinal, a two-urinal plane bathroom that takes the place of one toilet. Replacing a bathroom that serves all passengers with one that's made for only half the population may seem like a quick way to make the long-line problem worse, but there's some logic behind the proposed solution.

As Wouter Rogiest, a mathematician at Ghent University in Belgium, tells WIRED, gender-neutral bathroom lines are shortest when men have the option to head straight for a urinal. That's because it's quicker to use a urinal than a stall, and when men opt for the urinal, it frees up stalls for women. When he drew up an equation looking at hypothetical bathroom wait times at a concert, he found that a ratio of 14 toilets to eight urinals produced the most desirable wait times: one minute, 27 seconds for women and slightly under a minute for men. On a commercial plane, this ratio would come out to one or two Durinals per six conventional bathrooms.

Rogiest's concert equation isn't a perfect stand-in for airplane scenarios, so a more specific study would be needed before airlines could consider installing urinals. Unfortunately, if bathrooms with urinals do show up on airplanes, you can expect the spaces to be just as tight as they are now.

[h/t WIRED]

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United Airlines Has Gotten Rid of Tomato Juice, and Customers Are Freaking Out
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Lovers of tomato juice are a small camp, but a vocal one. And they're furious that United Airlines has replaced their beloved Mott's tomato juice with Mr. and Mrs. T Bloody Mary Mix on all flights under four hours, which includes most of its domestic runs. United said these changes are part of efforts to “streamline” its food service, the Chicago Business Journal reports.

The stealth substitution has fueled a rebellion among loyal tomato juice fans, as The Week points out.

There is some truth to the claim that tomato juice tastes better on flights. One study revealed that the noise level on an airplane affects our perception of taste, making savory or umami flavors more delicious. Another industry-funded study said the air pressure and humidity levels make bolder drinks seem more appealing.

Premium and economy passengers flying United can also say goodbye to Sprite Zero, Jim Beam, Courvoisier, and Amaretto, which were cut from the menu. And although airlines are not exactly known for their cuisine to begin with, passengers will likely start to see a difference in the types of meals being offered. The Chicago Business Journal writes:

"The reduction in food being offered in many instances in first-class and business-class cabins is not insignificant. Hot breakfasts are being replaced on some routes with only fruit plates and muffins, and more substantial lunches are being switched out for wraps and chocolate slabs."

The airline has said it is "monitoring customer feedback."

[h/t The Week]

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