Why Do Planes Climb So Steeply at Takeoff?

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iStock

Ron Wagner:

I’m going to guess that you mean commercial airliners on which you ride “go so steep.” Obviously, you feel they go steep, but “steep” is a relative term—one person’s “steep” is another person’s “boring.”

I’LL SHOW YOU “STEEP”

I had the good fortune to get taxpayer-funded pilot training through the U. S. Air Force, which included flying the Northrop T-38 Talon supersonic jet. When it was first introduced, it was the fastest-climbing aircraft in the world and set the world time-to-climb record.

The specific jet they used to set that record had the tail number of 10849. After that record-setting flight, 849 went to the regular training fleet at Webb AFB in Big Spring, Texas, which is where I went to pilot training. The folks at Edwards AFB, where the record was set, painted a list of the various records it had set on the nose, but otherwise, that jet was just a regular member of our fleet at Webb.

Eleven years later, I got to fly 849. Unfortunately, back then there was no such thing as smartphone cameras. If I’d had one, I would have gotten someone to take a pic of that list of records on the nose with me sitting in the cockpit—but, alas!

The records were set in meters, and they ticked off a bunch of them, but the easy one to remember is the climb to 9000 meters because that’s 30,000 feet.

The climb record must be measured from the moment the aircraft first moves on the runway, all the way through takeoff, gear up, and then start climbing. That whole process—from dead-stop on the runway to 30,00 feet—took 62 seconds ... and here’s a photo taken that day, like a scalded angel trying to get back to heaven.

A plane takes off at a steep incline
Quora

Now that’s what I call a “steep” takeoff.

Airliners do not take off “steep.”

BUT AIRLINERS DON’T HANG AROUND AT LOW ALTITUDE

Jet aircraft are most efficient at high altitudes. The most fuel efficient profile any jet can fly on a cross-country trip would be to climb at its maximum rate all the way to cruising altitude, level off and pull back to cruise power, and stay there until the precise moment the engines can be pulled to idle and descend to a landing.

Due to traffic and passenger comfort, the airliners don’t fly that maximum efficiency profile, but they try to get close.

And that’s why it seems to you that jet airliners climb “relatively steep,” but trust me, they do not fly steep. That T-38 climbed steep!

JUST FOR THE RECORD

A few years later, the F-4 broke the T-38′s record. I haven’t followed the latest, but I clearly recall in 1975 when the F-15 brought the 9000 meter record down to 48.8 seconds.

I just watched a video of an airliner takeoff and saw that it broke ground at about 50 seconds after brake release and they raised the gear at about one minute after brake release.

And so, to simplify this: From brake release, the F-15 can be at 30,000 in the time that a typical airliner is just raising its nose on the runway. Forty. Eight. Point. Eight. Seconds.

The F-15 has a thrust-to-weight ratio of greater than one, which means it can accelerate going perfectly vertical, like a ballistic rocket.

Now that, my friends, is the ultimate in “steep.”

This post originally appeared on Quora. Click here to view.

Why Do Hangovers Get Worse As You Get Older?

iStock/OcusFocus
iStock/OcusFocus

“I just can’t drink like I used to” is a common refrain among people pushing 30 and beyond. This is roughly the age when it starts getting harder to bounce back from a night of partying, and unfortunately, it keeps getting harder from there on out.

Even if you were the keg flip king or queen in college, consuming the same amount of beer at 29 that you consumed at 21 will likely have you guzzling Gatorade in bed the next day. It’s true that hangovers tend to worsen with age, and it’s not just because you have a lower alcohol tolerance from going out less. Age affects your body in various ways, and the way you process alcohol is one of them.

Because your body interprets alcohol as poison, your liver steps in to convert it into different chemicals that are easier to break down and eliminate from your body. As you get older, though, your liver produces less of the enzymes and antioxidants that help metabolize alcohol, according to a study from South Korea. One of these enzymes—called alcohol dehydrogenase (ADH)— has been called the “primary defense” against alcohol. It kicks off the multi-step process of alcohol metabolization by turning the beer or booze—or whatever you imbibed—into a chemical compound called acetaldehyde. Ironically, this substance is even more toxic than your tipple of choice, and a build-up of acetaldehyde can cause nausea, palpitations, and face flushing. It usually isn’t left in this state for long, though.

Another enzyme called aldehyde dehydrogenase (ALDH) helps convert the bad toxin into a new substance called acetate, which is a little like vinegar. Lastly, it’s converted into carbon dioxide or water and expelled from your body. You’ve probably heard the one-drink-per-hour recommendation, which is roughly how long it takes for your liver to complete this whole process.

So what does this mean for occasional drinkers whose mid-20s have come and gone? To summarize: As your liver enzymes diminish with age, your body becomes less efficient at metabolizing alcohol. The alcohol lingers longer in your body, leading to prolonged hangover symptoms like headaches and nausea.

This phenomenon can also partly be explained by the fact that our bodies tend to lose muscle and water over time. People with more body fat don’t break down alcohol as well, and less water in your body means that the booze stays concentrated in your system longer, The Cut reports. This is one of the reasons why women, who tend to have a higher body fat percentage than men, often suffer worse hangovers than their male counterparts. (Additionally, women have fewer ADH enzymes.)

More depressingly, as you get older, your immune system deteriorates through a process called immunosenescence. This means that recovering from anything—hangovers included—is more challenging with age. "When we get older, our whole recovery process for everything we do is harder, longer, and slower," gastroenterologist Mark Welton told Men’s Health.

This may seem like a buzzkill, but we're not telling you to put down the pint. However, if you're going to drink, just be aware of your body’s limitations. Shots of cotton candy-flavored vodka were a bad idea in college, and they’re an especially bad idea now. Trust us.

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What's the Difference Between a Break and a Fracture?

iStock.com/belterz
iStock.com/belterz

A lot of people tend to think that breaking a bone is worse than fracturing it—or perhaps they believe it's the other way around. Others may think of a fracture as a specific kind of break called a hairline crack. However, as Arkansas-based orthopedic surgeon Dr. C. Noel Henley points out in the YouTube video below, these are all common misconceptions. A fracture and a break are actually one and the same.

“There’s no difference between these two things,” he says. “A fracture means the cracking or breaking of a hard object. One is not worse than the other when it comes to breaking bones.”

Some of the confusion might stem from the fact that the word fracture is often used to describe specific kinds of breaks, as in compound fractures, oblique fractures, and comminuted fractures. In all cases, though, both break and fracture refer to any instance where “the normal structure of the bone has been disrupted and damaged,”  Henley notes.

This isn’t the only common misconception when it comes to cracked bones. The idea that a “clean break” is a good thing when compared to the alternative is a myth. Using the scaphoid bone in the wrist as an example, Dr. Henley says a clean break in the “wrong” bone can still be very, very bad. In some cases, surgery might be necessary.

According to the BBC, other bone myths include the belief that you’ll be unable to move a certain body part if your bone is broken, or that you’ll instantly know if you have a fracture because it will hurt. This isn’t always the case, and some people remain mobile—and oblivious to their injury—for some time after it occurs. Even if you think you have a minor sprain or something seemingly small like a broken toe, it’s still a good idea to see a doctor. It could be more serious than you realize.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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