The number one cause of plane crashes used to be controlled flight into terrain (pdf), accidents where pilots unintentionally collide with an obstacle. A pilot unable to see through fog, for example, could fly straight into a mountain, crashing an otherwise perfectly functional plane. Such accidents killed over 9000 people—until aviation engineer Don Bateman’s crash-avoidance technology changed all that.
Bateman invented the original Ground Proximity Warning System (GPWS) in the 1970s. Using information from the altimeter. airspeed indicator, and other devices already standard in planes, the original GPWS warned pilots with increasing urgency—first “Caution—Terrain,” then “Pull up! Pull up!”—if the plane was due to crash. Bateman, now 79 years old, still works at Honeywell and he’s still perfecting the GPWS. The modern warning system integrates GPS locations of potential obstacles. In a profile of Bateman for the Seattle Times, Bob Voss, chief executive of the Flight Safety Foundation, says, “It’s accepted within the industry that Don Bateman has probably saved more lives than any single person in the history of aviation.”
Flapping while running up a ramp takes far
less energy than flight at the same angle.
What’s the News: How did birds get their wings? And how did they start using them to fly? These questions have bedeviled evolutionary biologists for more than a century, and with flight’s origins long buried, a lot of careful measurements of how modern birds work combined with clever guesswork has resulted in several fiercely differing theories. The two major camps have proto-birds either dropping from trees or running along the ground before finally taking to the air.
A new study lends credence to the idea that flapping wings while running could have been involved by showing that it requires much less energy than flying while still helping birds get over obstacles. This suggests that it could have been an easy way for proto-birds to start going through the motions.
What’s the News:Virgin Galactic’s plans for taking tourists into space have inched closer to fulfillment: earlier this month, the company’s SpaceShipTwo successfully demonstrated the technique, called “feathering,” that will allow the ship to reenter Earth’s atmosphere. In this video, you can watch the ship, designed to behave like a badminton shuttlecock, tip and roll as the pilot flips the craft’s tail to a 65 degree angle, which will brake SpaceShipTwo while it’s still high in the atmosphere. This means the ship will descend slowly enough to keep from igniting as it reenters.
What’s the News: Bats have to use twice as much energy to fly when they’re wet as when they’re dry, a new study in Biology Letters found, which may help explain why many bats refrain from flying in heavy rain.
They may not be as adorable as sugar gliders, but they’re just as accomplished: Five species of Asian snake have also developed the ability to “fly” or glide from tree to tree, flattening out their bodies to travel up to 80 feet.
Researcher Jake Socha and his team studied the glide of Chrysopelea paradisi snake and took videos of the snakes in flight, which Socha presented at an ongoing meeting of the American Physical Society. He found that before a snake takes the leap it curls its body into a J-shape, and then launches itself from the tree branch. In the air, it flattens its body and undulates, as if slithering through the air.
The snake differs from other gliding species, like gliding lizards and flying squirrels, in that it doesn’t have specialized body parts that act as wings.
“The whole snake itself is just one long wing,” Socha said. “That wing is constantly reconfiguring, it’s constantly reforming and contorting.” [LiveScience]
Hit the jump for a video of the snake in action. (more…)
The enormous wings of pterosaurs testify to the idea that these giant reptiles, which lived at the same time as dinosaurs, would have been masters of flight. But there’s one thing that nags paleontologists: pterosaur takeoff. Just how does a giraffe-sized creature get off the ground?
Birds rely on the strength of their legs to leap into the air or run to gain speed for take-off. Pterosaurs walked on all four limbs, and Habib has developed an anatomical model to explore how they might have launched themselves using their small hind limbs and larger “arms” which formed part of their wings. The animal could have launched itself like a pole vaulter, pushing forward with its hind limbs and using its powerful arms to thrust it high enough into the air to stretch its wings and fly away. [New Scientist]
Here’s a new creature for the record books. In Chile, paleontologists have found the fossilized remains of a huge, toothy bird whose wingspan stretched 17 feet across. That means the bird, Pelagornis chilensis or “huge pseudoteeth,” had one of the longest wingspan ever recorded–a wingspan that was about as long as a giraffe is high.
This newly named species belongs to a group known as pelagornithids, birds that had bony tooth-like projections and long beaks. The well-preserved fossil that researchers turned up belonged to a bird that weighed about 64 pounds and had relatively light, thin-walled bones, according to the description published in the Journal of Vertebrate Paleontology. It cruised the skies between 5 and 10 million years ago.
Science: It’s best with stuffed fish and a wind tunnel.
When flying fish leap from the water and glide through the air, they appear as streamlined as any bird or insect. But how does one put that assumption to the test? Easy: Catch flying fish from the Sea of Japan (or East Sea, as South Korea calls it), kill them, stuff them, place them in a wind tunnel, and turn on the breeze.
Hyungmin Park and Haecheon Choi did just that. Their study of airflow around the fish, which is out in The Journal of Experimental Biology, concludes that flying fish glide as efficiently as some birds, and perhaps even more so than some flying insects.
Though the wing-flapping contraptions of early human flight haven’t quite caught on, researchers think birds may still have something to teach us about navigating the air: how to land. MIT researchers have made a system that can bring a modified glider to an elegant bird-like stop, causing it to set down on its tail.
Russ Tedrake of MIT’s Computer Science and Artificial Intelligence Laboratory and his student Rick Cory developed the computer model to bring a basic foam glider to a unique landing. The principle behind the plane’s stop is the same one used by stunt planes–stall. When its wings tilt back, the plane loses lift and falls from the sky. Traditional planes don’t use this method to land because the airflow is chaotic (see smoke visualization above) making it hard to predict how the plane will behave.
Birds come to a stop by tilting their wings back at sharp angles. This creates turbulence and large, unpredictable whirlwinds behind the wings. If an airplane pointed its wings up in this way, it would lose lift and fall out of the sky. But MIT researchers wanted to take advantage of stall–specifically, post-stall drag–to help a plane come to a controlled landing. [Popular Science]
Success for Solar Impulse: This morning the solar-powered plane touched down in Switzerland after more than 26 hours in the sky—including flying overnight on battery power.
As we noted yesterday, this was by far the most ambitious test of adventurer Bertrand Piccard’s experimental aircraft, which is covered by 12,000 solar cells. Swiss pilot André Borschberg had to decide last night whether those cells had absorbed enough battery power during the day to coast through the night, and he managed to do it.
“I’ve been a pilot for 40 years now, but this flight has been the most incredible one of my flying career,” Mr. Borschberg said as he landed, according to a statement from the organizers of the project. “Just sitting there and watching the battery charge level rise and rise thanks to the sun. I have just flown more than 26 hours without using a drop of fuel and without causing any pollution” [The New York Times].
As I write this, a plane powered by the sun is flying somewhere over Europe, undertaking its most ambitious test flight yet.
When we last left the Solar Impulse back in April, the experimental aircraft had flown a two-hour test to prove it was flight-worthy. Today, the pilot in the plane, which weighs about as much as a car and is covered in 12,000 solar cells, will try to stay aloft for 24 hours, even cruising along during the nighttime hours.
“The goal of the project is to have a solar-powered plane flying day and night without fuel,” said team co-founder Bertrand Piccard, adding that this test flight – the third major step after its first ‘flea hop’ and an extended flight earlier this year – will demonstrate whether the ultimate plan is feasible: to fly the plane around the world. “This flight is crucial for the credibility of the project” [AP].
It was a big week for experimental military aircraft, with the Air Force’s secretive X-37B space plane and the Navy’s biofuel-powered “Green Hornet” both achieving successful test flights. But the most ambitious—the HTV-2 hypersonic glider under development by the Defense Advanced Research Projects Agency (DARPA)—lost contact with its operators during its run.
Launched from Vandenberg AFB, Calif. on April 22, the unmanned HTV-2 was planned to cross the Pacific and impact the ocean north of Kwajalein Atoll in the first of two flights to demonstrate technology for a prompt global strike weapon [Aviation Week]. It successfully achieved separation from its booster rocket high in the atmosphere; however, nine minutes into the test the glider lost communication. Now the military is studying the test flight telemetry to figure out where the HTV-2 would have crashed down.
The F/A-18 Super Hornet burns through more fuel than any other aircraft in the United States Navy, whose pilots have flown more than 400 of the jets. But with the week of Earth Day upon us, the Navy is trying to use the jet to show it can mend its fuel-guzzling ways. Tomorrow the “Green Hornet,” an F/A-18 running on a half-petroleum, half-biofuel blend, will make a test flight from Maryland.
Secretary of the Navy Ray Mabus has set a target that half of naval energy consumption will come from alternative sources by 2020. A “Great Green Fleet,” to sail by 2016, will include nuclear ships, as well as surface combatants with hybrid electric power systems using biofuel and biofuel-powered aircraft [National Geographic]. Before we can talk about ambitious deployment targets, however, the Navy has to prove that its “green” fighter has got what it takes, and so the experimental F/A-18 will try to break the sound barrier.
For the better part of a decade, the Global Hawk unmanned aerial vehicle has coasted through the stratosphere, surveilling vast panoramas of land below for the U.S. Air Force and Navy. Now the plane’s broad reach will serve science. NASA announced this week that it had completed the first test flight of a Global Hawk retrofitted with monitoring equipment to help scientists study the the oceans, the atmosphere, and more.
“We can go to regions we couldn’t reach or go to previously explored regions and study them for extended periods that are impossible with conventional planes,” said David Fahey, co-mission scientist and research physicist [CNN]. From the comfort of their offices in Dryden Flight Research Center in the Mojave Desert, pilots flew the plane 14 hours up to the Arctic Ocean on this test run. Though this flight lasted about 14 hours, the Global Hawk can stay aloft for 30, and reach altitudes of 60,000, or twice as high as your last commercial airline flight attained.
When you see a flock of birds flying in formation, it might seem like their group dynamics are fairly simple: The one out front leads the way. But does the same birds always take the lead in a group? And do the birds in the back follow the overall leader, or rather the middle managers in front of them?
To find out, Tamás Vicsek and colleagues strapped backpacks equipped with GPS sensors to pigeons for a study out this week in Nature. The lightweight trackers recorded the birds on both solo flights and group flight and measured their positions five times per second. Indeed, Vicsek found, birds fly according to the group pecking order, with the leader out front. When it changed direction, its direct followers would do the same in less than a second, and then the more junior members of the group would respond to the direction of those middle managers.
But there were surprises, too. Sometimes the lead bird wouldn’t fly out front; it may have been tired from leading the pack and needed some time off. So perhaps birds are like cycling teams, occasionally trading off who carries the taxing burden of leading the group.
For more details about the study—including why it’s not as obvious as you might think that the leading bird flies in the front of the group, and why left and right matter so much to pigeons—check out DISCOVER blogger Ed Yong’s post at Not Exactly Rocket Science.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
What’s the News: Bats have to use twice as much energy to fly when they’re wet as when they’re dry, a new 
The enormous wings of 
Here’s a new creature for the record books. In Chile, paleontologists have found the fossilized remains of a huge, toothy bird whose wingspan stretched 17 feet across. That means the bird, Pelagornis chilensis or “huge pseudoteeth,” had one of the longest wingspan ever recorded–a wingspan that was about as long as a giraffe is high.
Science: It’s best with stuffed fish and a wind tunnel.
Success for Solar Impulse: This morning the solar-powered plane touched down in Switzerland after more than 26 hours in the sky—including flying overnight on battery power.
As I write this, a plane 
It was a big week for experimental military aircraft, with the Air Force’s 
For the better part of a decade, the Global Hawk unmanned aerial vehicle has coasted through the stratosphere, surveilling vast panoramas of land below for the U.S. Air Force and Navy. Now the plane’s broad reach will serve science. NASA announced this week that it had completed the first test flight of a Global Hawk retrofitted with monitoring equipment to help scientists study the the oceans, the atmosphere, and more.
When you see a flock of birds flying in formation, it might seem like their group dynamics are fairly simple: The one out front leads the way. But does the same birds always take the lead in a group? And do the birds in the back follow the overall leader, or rather the middle managers in front of them?
