What Would Happen If a Plane Flew Too High?

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iStock

Tom Farrier:

People have done this, and they have died doing it. For example, in October 2004, the crew of Pinnacle Airlines 3701 [PDF]  was taking their aircraft from one airport to another without passengers—a so-called "repositioning" flight.

They were supposed to fly at 33,000 feet, but instead requested and climbed to 41,000 feet, which was the maximum altitude at which the aircraft was supposed to be able to be flown. Both engines failed, the crew couldn't get them restarted, and the aircraft crashed and was destroyed.

The National Transportation Safety Board determined that the probable causes of this accident were: (1) the pilots’ unprofessional behavior, deviation from standard operating procedures, and poor airmanship, which resulted in an in-flight emergency from which they were unable to recover, in part because of the pilots’ inadequate training; (2) the pilots’ failure to prepare for an emergency landing in a timely manner, including communicating with air traffic controllers immediately after the emergency about the loss of both engines and the availability of landing sites; and (3) the pilots’ improper management of the double engine failure checklist, which allowed the engine cores to stop rotating and resulted in the core lock engine condition.

Contributing to this accident were: (1) the core lock engine condition, which prevented at least one engine from being restarted, and (2) the airplane flight manuals that did not communicate to pilots the importance of maintaining a minimum airspeed to keep the engine cores rotating.

Accidents also happen when the "density altitude"—a combination of the temperature and atmospheric pressure at a given location—is too high. At high altitude on a hot day, some types of aircraft simply can't climb. They might get off the ground after attempting a takeoff, but then they can't gain altitude and they crash because they run out of room in front of them or because they try to turn back to the airport and stall the aircraft in doing so. An example of this scenario is described in WPR12LA283.

There's a helicopter version of this problem as well. Helicopter crews calculate the "power available" at a given pressure altitude and temperature, and then compare that to the "power required" under those same conditions. The latter are different for hovering "in ground effect" (IGE, with the benefit of a level surface against which their rotor system can push) and "out of ground effect" (OGE, where the rotor system supports the full weight of the aircraft).

It's kind of unnerving to take off from, say, a helipad on top of a building and go from hovering in ground effect and moving forward to suddenly find yourself in an OGE situation, not having enough power to keep hovering as you slide out over the edge of the roof. This is why helicopter pilots always will establish a positive rate of climb from such environments as quickly as possible—when you get moving forward at around 15 to 20 knots, the movement of air through the rotor system provides some extra ("translational") lift.

It also feels ugly to drop below that translational lift airspeed too high above the surface and abruptly be in a power deficit situation—maybe you have IGE power, but you don't have OGE power. In such cases, you may not have enough power to cushion your landing as you don't so much fly as plummet. (Any Monty Python fans?)

Finally, for some insight into the pure aerodynamics at play when airplanes fly too high, I'd recommend reading the responses to "What happens to aircraft that depart controlled flight at the coffin corner?"

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

Turn Your LEGO Bricks Into a Drone With the Flybrix Drone Kit

Flyxbrix/FatBrain
Flyxbrix/FatBrain

Now more than ever, it’s important to have a good hobby. Of course, a lot of people—maybe even you—have been obsessed with learning TikTok dances and baking sourdough bread for the last few months, but those hobbies can wear out their welcome pretty fast. So if you or someone you love is looking for something that’s a little more intellectually stimulating, you need to check out the Flybrix LEGO drone kit from Fat Brain Toys.

What is a Flybrix LEGO Drone Kit?

The Flybrix drone kit lets you build your own drones out of LEGO bricks and fly them around your house using your smartphone as a remote control (via Bluetooth). The kit itself comes with absolutely everything you need to start flying almost immediately, including a bag of 56-plus LEGO bricks, a LEGO figure pilot, eight quick-connect motors, eight propellers, a propeller wrench, a pre-programmed Flybrix flight board PCB, a USB data cord, a LiPo battery, and a USB LiPo battery charger. All you’ll have to do is download the Flybrix Configuration Software, the Bluetooth Flight Control App, and access online instructions and tutorials.

Experiment with your own designs.

The Flybrix LEGO drone kit is specifically designed to promote exploration and experimentation. All the components are tough and can totally withstand a few crash landings, so you can build and rebuild your own drones until you come up with the perfect design. Then you can do it all again. Try different motor arrangements, add your own LEGO bricks, experiment with different shapes—this kit is a wannabe engineer’s dream.

For the more advanced STEM learners out there, Flybrix lets you experiment with coding and block-based coding. It uses an arduino-based hackable circuit board, and the Flybrix app has advanced features that let you try your hand at software design.

Who is the Flybrix LEGO Drone Kit for?

Flybrix is a really fun way to introduce a number of core STEM concepts, which makes it ideal for kids—and technically, that’s who it was designed for. But because engineering and coding can get a little complicated, the recommended age for independent experimentation is 13 and up. However, kids younger than 13 can certainly work on Flybrix drones with the help of their parents. In fact, it actually makes a fantastic family hobby.

Ready to start building your own LEGO drones? Click here to order your Flybrix kit today for $198.

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Why Are Common Graves Called Potter’s Fields?

Graves in potter's fields are sometimes marked with blank headstones or crosses.
Graves in potter's fields are sometimes marked with blank headstones or crosses.
vyasphoto/iStock via Getty Images

For centuries, regions around the world have maintained common graves called potter’s fields, where they bury unidentified victims and impoverished citizens who couldn’t afford their own cemetery plots. The term potter’s field has been around for just as long.

The earliest known reference to a potter’s field is from the Gospel of Matthew, which historians believe was written sometime during the 1st century. In it, a remorseful Judas gives the 30 silver coins he was paid for betraying Jesus back to the high priests, who use it to purchase a “potter’s field” where they can bury foreigners. It’s been speculated that the priests chose land from a potter either because it had already been stripped of clay and couldn’t be used for farming, or because its existing holes and ditches made it a particularly good place for graves. But Matthew doesn’t go into detail, and as the Grammarphobia Blog points out, there’s no evidence to prove that the original potter’s field was ever actually used for its clay resources—it could’ve just been a parcel of land owned by a potter.

Whatever the case, the term eventually caught on as English-language versions of the Bible made their way across the globe. In 1382, John Wycliffe translated it from Latin to Middle English, using the phrase “a feeld of a potter,” and William Tyndale’s 1526 Greek-to-English translation of the passage featured “a potters felde,” which was altered slightly to “potters field” in King James’s 1611 edition.

Around the same time, a new definition of potter was gaining popularity that had nothing to do with pottery—in the 16th century, people began using the word as a synonym for tramp or vagrant. According to the Oxford English Dictionary, it was first written in a 1525 Robin Hood tale, and William Wordsworth mentioned it in his 1798 poem “The Female Vagrant.” It’s likely that this sense of the word helped reinforce the idea that a potter’s field was intended for the graves of the unknown.

It’s also definitely not the only phrase we’ve borrowed from the Bible. From at your wit’s end to a fly in the ointment, here are 18 everyday expressions with holy origins.

[h/t Grammarphobia Blog]