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Making the Brazilian ATR-72 Spin
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Note: This story was corrected on August 10th at 10:23 am, thanks to the help of a sharp-eyed reader.
Making an ATR-72 Spin
I wasn’t in Brazil on Friday afternoon, but I saw the post on Twitter or X (or whatever you call it) showing a Brazil ATR-72, Voepass Airlines flight 2283, rotating in a spin as it plunged to the ground near Sao Paulo from its 17,000-foot cruising altitude. All 61 people aboard perished in the ensuing crash and fire. A timeline from FlightRadar 24 indicates that the fall only lasted about a minute, so the aircraft was clearly out of control. Industry research shows Loss of Control in Flight (LOCI) continues to be responsible for more fatalities worldwide than any other kind of aircraft accident.
The big question is why the crew lost control of this airplane. The ADS-B data from FlightRadar 24 does offer a couple of possible clues. The ATR’s speed declined during the descent rather than increased, which means the aircraft’s wing was probably stalled. The ATR’s airfoil had exceeded its critical angle of attack and lacked sufficient lift to remain airborne. Add to this the rotation observed, and the only answer is a spin.
Can a Large Airplane Spin?
The simple answer is yes. If you induce rotation to almost any aircraft while the wing is stalled, it can spin, even an aircraft as large as the ATR-72. By the way, the largest of the ATR models, the 600, weighs nearly 51,000 pounds.
Of course, investigators will ask why the ATR’s wing was stalled. It could have been related to a failed engine or ice on the wings or tailplane. (more…)
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How the FAA Let Remote Tower Technology Slip Right Through Its Fingers
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In June 2023, the FAA published a 167-page document outlining the agency’s desire to replace dozens of 40-year-old airport control towers with new environmentally friendly brick-and-mortar structures. These towers are, of course, where hundreds of air traffic controllers ply their trade … ensuring the aircraft within their local airspace are safely separated from each other during landing and takeoff.
The FAA’s report was part of President Biden’s Infrastructure Investment and Jobs Act enacted on November 15, 2021. That bill set aside a whopping $25 billion spread across five years to cover the cost of replacing those aging towers. The agency said it considered a number of alternatives about how to spend that $5 billion each year, rather than on brick and mortar buildings.
One alternative addressed only briefly before rejecting it was a relatively new concept called a Remote Tower, originally created by Saab in Europe in partnership with the Virginia-based VSATSLab Inc. The European technology giant has been successfully running Remote Towers in place of the traditional buildings in Europe for almost 10 years. One of Saab’s more well-known Remote Tower sites is at London City Airport. London also plans to create a virtual backup ATC facility at London Heathrow, the busiest airport in Europe.
A remote tower and its associated technology replace the traditional 60-70 foot glass domed control tower building you might see at your local airport, but it doesn’t eliminate any human air traffic controllers or their roles in keeping aircraft separated.
Max Trescott photo Inside a Remote Tower Operation
In place of a normal control tower building, the airport erects a small steel tower or even an 8-inch diameter pole perhaps 20-40 feet high, similar to a radio or cell phone tower. Dozens of high-definition cameras are attached to the new Remote Tower’s structure, each aimed at an arrival or departure path, as well as various ramps around the airport.
Using HD cameras, controllers can zoom in on any given point within the camera’s range, say an aircraft on final approach. The only way to accomplish that in a control tower today is if the controller picks up a pair of binoculars. The HD cameras also offer infrared capabilities to allow for better-than-human visuals, especially during bad weather or at night.
The next step in constructing a remote tower is locating the control room where the video feeds will terminate. Instead of the round glass room perched atop a standard control tower, imagine a semi-circular room located at ground level. Inside that room, the walls are lined with 14, 55-inch high-definition video screens hung next to each other with the wider portion of the screen running top to bottom.
After connecting the video feeds, the compression technology manages to consolidate 360 degrees of viewing area into a 220-degree spread across the video screens. That creates essentially the same view of the entire airport that a controller would normally see out the windows of the tower cab without the need to move their head more than 220 degrees. Another Remote Tower benefit is that each aircraft within visual range can be tagged with that aircraft’s tail number, just as it might if the controller were looking at a radar screen. (more…)
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The Aesthetics of Collision Avoidance
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When it came time for Dennis Hutchinson to paint the Davis DA-2 he’d restored, he picked red and white with gold and blue accents, “because I like them and think they go well together.”
Aesthetics had little do with how he arranged those colors on the airframe. Collision avoidance was top of mind: “As small as the Davis is, I wanted it to be as visible as possible in flight, to pop out of the background, not blend in,” said Hutchinson, who’s based at the Indianapolis Regional Airport (MQJ) in Greenfield, Indiana.
Starting in gliders, Hutchinson has been a pilot for half a century. When Leeon Davis flew his prototype DA-2, with its 19-foot-3 wingspan and 17-foot-10 fuselage, in 1966, Hutchinson was two years away from soloing a glider, at age 14, after his 13th flight. He got his private at 15, before he was eligible for a driver’s license.
“Most sailplanes are painted white, to protect their composite structures,” he said. “What I’d observed from an early age was that sailplanes with even a small amount of darker, contrasting paint on the nose and wingtips were much easier to spot in flight that those with an all white finish.”
That’s why the tips of the Davis’s constant-chord wing and V-tail are red, because they contrast with the white inboard sections. The upper fuselage is white because it stands out against the darker earth when viewed from above, just as the red on the lower fuselage does against the sky when seen from below.
Going beyond this aesthetic contribution to collision avoidance, Hutchinson installed an AeroLED package of position/navigation/strobe lights on the wingtips and tail cone. “They are interconnected and flash simultaneously, to great effect.”
The landing and taxi lights are mounted in each wing, and they are capable of wig-wag mode. “They are not interconnected with the strobes, so they flash at a different rate,” he said. “Since all the lights are LEDs, the power they draw is minimal, and I highly value the extra visibility.”
Hutchinson said the combination of his collision avoidance paint scheme and lights is working, because when he arrives at a new airport, right after asking what kind of plane he’s flying (His initial answer? “It’s a freeze-dried Bonanza.”) pilots “tell me that the plane is lit up like a Christmas tree.” — Scott Spangler, Editor
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Bruce McCandless, the Astronaut in the Iconic Photo
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Bruce McCandless, the Astronaut In the Iconic Photo, by Micah Engber
Listen to the episode or read it below
When you think about the first space walk maybe you think about Cosmonaut Alexei Leonov who in March 1965 was the first man to ever leave the relative safety of a space capsule. Maybe it’s Ed White you think of, who in June 1965 opened the hatch of Gemini 4 and was the first American to walk in space.
The name Gene Cernan may come to mind. He flew Gemini 9A in June of 1966 and spent over two hours on an EVA. That EVA almost killed him due to our lack of understanding of the physical exertion it took to work in space, and the cooling system in his space suit not being able to keep up with it.
Then there’s Buzz Aldrin, sure, the second man on the moon, but actually the first man to successfully conduct a mission while on a space walk. In November 1966, on Gemini 12, the final Gemini mission, Buzz Aldrin conducted 3 EVAs that totaled more than five hours in space. Buzz Aldrin was the man that really taught us how to work in space.
EVAs seem rather common place today. Even though they’re always incredibly dangerous, always a challenge, and always very closely monitored both from on board the space craft and from the ground; the general public doesn’t think of EVA’s as anything special. In some ways that’s sad. It’s also sad that we also don’t think of the man that paved the way for the modern spacewalk, probably don’t know his name, and certainly don’t have any idea that he passed away on December 21 of 2017.
In February 1984, at the age of 39, Bruce McCandless was the first person to ever truly walk in space, and by truly, I mean untethered. You see, those four space walks I mentioned before, while all incredible feats of both courage and science, all had one thing in common, those men were tethered to their spacecraft, connected by an umbilical cord. Although in an emergency, none of them could be safely pulled back into their spacecraft by the tether, they couldn’t just go floating off in space. On the other hand, in February 1984, Bruce McCandless flew in space, no strings attached; he piloted himself in what we called the MMU, the Manned Maneuvering Unit. (more…)