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Higher Than Everest

If you were to wear an altimeter watch on an airplane, what would the elevation reading be?

Question:

If you were to wear an altimeter watch on an airplane, what would the elevation reading be?

Submitted by - T.P., Eugene, OR

Answer:

If you’re flying at 36,000 feet, and your watch registers 36,000 feet&ndashyou’ve got a problem.

Fortunately, airplane cabins are pressured “for your comfort,” as the pre-flight recording reminds us. If the cabin wasn’t pressurized, you’d have a few seconds to realize it before you passed out due to lack of oxygen and pressure. But now for the answer: Most commercial aircraft are pressurized to between 5,000 and 8,000 feet of elevation during flights. This means the pressure is the same as what you would experience if you stood on top of a 5,000 to 8,000-foot tall mountain. And since altimeter watches work by measuring the local barometric pressure, your watch should read between 5,000 and 8,000 feet. Airplanes aren’t pressured to sea level because the force of the air pushing outward on the fuselage would weaken the plane’s structural integrity and lifespan. One more thing. You know why so many people fall asleep in airplanes just before takeoff? Lowering the air pressure inside the cabin actually makes you drowsier, and also causes your ears to pop.

1 Comment

  1. sophia

    right…because we should trust someone who doesn’t know what “quotation marks” are for – namely, direct quotes. notice that the phrase “negative pressurize” NEVER appears in buck’s response…

    furthermore, it’s not true that the greater the differential pressure, the stronger a hollow structure – the strength of the structure is further dependent on the strength of the materials from which it is made. let’s take that cylindrical balloon as an example. yes, a fully inflated balloon is stronger than a half-inflated balloon. but what happens if we try to add more air to this already fully inflated balloon (keeping all other things equal)? it pops. because the pressure can only become so great (and the structure so strong) before the materials give out. so there’s a maximum differential pressure which creates the strongest hollow structure – which is exactly what buck is saying. they don’t pressurize a cabin to sea-level because doing so would cause the differential pressure to become too large, coming too close to that balloon-popping point.

    maybe you should watch who you call stupid.

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