When Flying, Why is Taking Off More Dangerous Than Landing?


Why is taking off more dangerous than landing?

Tom Farrier:

Landing is generally considered quite a bit more hazardous (and requires a bit more exacting handling), but both takeoffs and landings can have their challenges. Still, aircraft like to fly; sometimes it can be a little tricky to encourage them to stop doing so at the end of a flight, especially in the presence of unpredictable winds or slippery runways.

This is a graphic from my favorite go-to reference on commercial aircraft accidents, updated annually by Boeing but including all airliner accidents:

The shaded area under the aircraft silhouette shows the amount of time an aircraft spends in each “phase of flight.” At the top, there are two numbers worth looking at carefully. Final approach and landing is when 48 percent—essentially half—of all fatal accidents that have occurred from 1959 through 2016. By contrast, taking off and starting to climb is only about a quarter as hazardous (13 percent). These ratios used to be somewhat different; takeoffs used to see their share of accidents a lot more frequently than today.

The biggest challenge with taking off in the early days of jet airliners was the rate at which they could accelerate during their takeoff roll. Often, a lot of time was required between when the aircraft passed the speed at which the pilots were committed to taking off (V1) and when the jet actually could get into the air with a positive rate of climb. When an emergency would suddenly present itself in that window of vulnerability, sometimes there were no good options, and sometimes the pilots picked the wrong one.

One of the biggest ways pilots (and flight engineers in aircraft that use them) have to earn their paychecks is when something bad happens during a takeoff roll and they have to decide whether to continue the takeoff and deal with the problem in the air, or if the situation is critical enough that it’d be preferable to wrestle the fuel-laden beast on the ground and risk going off the end of the runway.

To try to address the need for added clarity in such situations, some of these early accidents led to recognition of the need for establishing a second speed benchmark (V2), which is the point at which the aircraft is going fast enough to make a successful takeoff with one engine out. Bear in mind that a lot of the biggest early jets had four engines, none of which was nearly as powerful as the current generation (some actually used water injection systems to boost their thrust during takeoff), and which suffered failures a lot more often.

“Rejected takeoffs” are pretty rare occurrences these days, and airport design has gotten better at minimizing the consequences of an aircraft running off the end of a runway if circumstances conspire to make things exciting for its inhabitants. For example, "engineered material arresting systems” are basically long slabs of pavement designed to collapse under the weight of an aircraft, grabbing hold of it and bringing it to a fairly enthusiastic stop.

This may not sound desirable, but some of the places EMAS has been installed (including Boston’s Logan and New York’s LaGuardia Airports) have seen more than their share of aircraft in trouble winding up in bodies of water during what are euphemistically (but accurately) referred to as “runway excursions.”

Such departures can happen either during takeoff or landing emergencies, and it’s nice to know that the chances of surviving both have been improved significantly with one ingenious invention.

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

Where Did the Phrase 'Red Herring' Come From?

iStock.com/Mathias Darmell
iStock.com/Mathias Darmell

You may have seen a red herring in a recent book or movie, but you probably only realized it after the fact. These misleading clues are designed to trick you into drawing an incorrect conclusion, and they're a popular ploy among storytellers of all stripes.

If you've seen or read the Harry Potter series—and really, who hasn’t?—then you may recall some of the many instances where J.K. Rowling employed this literary device. That endearing plot twist about the nature of Snape's character, for example, is likely one of the longest-running red herrings ever written.

Sometimes they aren't even subtle. Agatha Christie's murder mystery And Then There Were None directly mentions red herring in reference to a character's death, and a statue of a red herring appears in Lemony Snicket's A Series of Unfortunate Events. Perhaps most blatantly, a character in the cartoon A Pup Named Scooby-Doo who was constantly being blamed for myriad crimes was named—you guessed it—Red Herring.

But where does this literary device come from, and why is it named after a fish? For a bit of background: herring are naturally a silvery hue, but they turn reddish-brown when they're smoked. Long before refrigerators were invented, this was done to preserve the fish for months at a time. They can also be pretty smelly. As Gizmodo's io9 blog points out, it was believed that red herring were dragged against the ground to help train hounds to sniff out prey in the 17th century. Another theory was that escaped prisoners used the fish to cover their tracks and confuse the dogs that tailed them.

However, io9 notes that red herring were actually used to train horses rather than dogs, and only if the preferred choice—a dead cat—wasn't available. The idea was that the horses would get used to following the scent trail, which in turn would make them less likely to get spooked while "following the hounds amid the noise and bustle of a fox hunt," notes British etymologist and writer Michael Quinion, who researched the origin of the phrase red herring.

The actual origin of the figurative sense of the phrase can be traced back to the early 1800s. Around this time, English journalist William Cobbett wrote a presumably fictional story about how he had used red herring as a boy to throw hounds off the scent of a hare. He elaborated on this anecdote and used it to criticize some of his fellow journalists. "He used the story as a metaphor to decry the press, which had allowed itself to be misled by false information about a supposed defeat of Napoleon," Quinion writes in a blog. "This caused them to take their attention off important domestic matters."

According to Quinion, an extended version of this story was printed in 1833, and the idiom spread from there. Although many people are more familiar with red herrings in pop culture, they also crop up in political spheres and debates of all kinds. Robert J. Gula, the author of Nonsense: Red Herrings, Straw Men and Sacred Cows: How We Abuse Logic in Our Everyday Language, defines a red herring as "a detail or remark inserted into a discussion, either intentionally or unintentionally, that sidetracks the discussion."

The goal is to distract the listener or opponent from the original topic, and it's considered a type of flawed reasoning—or, more fancifully, a logical fallacy. This application of red herring seems to be more in line with its original usage, but as Quinion notes: "This does nothing to change the sense of red herring, of course: it's been for too long a fixed part of our vocabulary for it to change. But at least we now know its origin. Another obscure etymology has been nailed down."

What Is the Shelf Life of Donated Eyes?


Zoe-Anne Barcellos:

I can only answer for cornea and eye donation.

The FDA does all oversight (no pun intended) of organ disposition.

The main organs—heart, liver, pancreas, lungs, etc.—are transplanted within hours. They are just not viable if they are not being perfused constantly.

The other tissues—like bone, skin, tendons, etc.—do not need to be transplanted immediately. But I am not sure on the regulations of when they need to be transplanted.

With the eyes, there are four tissues that can be recovered.

We recover whole eyes for research and education purposes. These usually go much faster, but we can hold them up to a year.

Conjunctiva can also be recovered; conjunctiva is a clear covering over most of the eye (it is what gets irritated when you have pink eye). I have been working as a recovery tech for five years, and our office has not had a request for "conj" in all that time. I believe it is mostly used for research, but I could be wrong.

Sclera is the white area of your eye. It is fairly thick and flexible. If you have ever touched a reptile egg, that is what it reminds me of. We recover sclera for transplant. They use it for several things, but mainly to patch punctures. Similar to if you pop the inner tube of your bike and repair it. Sclera can also be used to repair ear drums. We can hold on to this for up to a year.

The main thing we recover is corneas. In the U.S., we must transplant these within seven days of recovery. (Recovery is usually within hours of death, but we can push it up to 20 hours after if needed.) Sometimes we have more corneas than we need, and then they are shipped overseas and transplanted up to 14 days after recovery. There is no real different outcome with the later transplant time, but the FDA in the U.S. made the rules. (You can sign up to be an organ, tissue, and eye donor here.)

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