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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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An Introductory Flight of Frustration
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Following Santa’s directions, for Christmas my oldest son’s wife got him an introductory flight lesson. I can’t remember any gift in the preceding years that left him so excited. An ICU nurse living in the metropolitan Kansas City, it took awhile for the weather to align with his work and family schedules (that happens when you have four kids). But he was patient, and his eager anticipation never dimmed, until he actually made the flight.
On his way home from the airport he called in a state of agitated consternation. To summarize our hour long conversation, the intro lesson was much less than he anticipated, and he pelted me with a series of questions whose common denominator was, “Was I expecting too much?” As he stepped through the lesson, if you could call it that, the answer to each question was no. What Santa brought you was not an introductory flight lesson but an hour of flight time for a safety pilot posing as a CFI.
My son described him as a “professor,” of what he didn’t know or say. He was “older than me, but not as old as you, Pops,” which put him somewhere between 31 and 64. And there was very little conversation before the flight. He didn’t ask why my son wanted to become a pilot and how he hoped to use this precious, hard-earned skill once he’d earned the certificate. Nor was there any preflight discussion of what they would do during the lesson. “He checked the oil and said, “Let’s go flying.’” said my son.
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Tactile History at Naval Aviation Museum
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A lot has changed since I last visited the National Museum of Naval Aviation 46 years ago, when I was a student at the Naval Schools of Photography that once called
the Naval Air Station Pensacola, Florida, home. The photo school, and the occupational rating itself, are no more. The Navy merged four jobs—photographer’s mate, illustrator draftsman, lithographer, and journalist—into a new Mass Communication Specialist designation in 2006, and the classic white structure that was its home became the air station’s headquarters. Likewise, time has replaced the museum’s World War II temporary buildings surrounded by the open-air bondage of a dozen or so aircraft (the more delicate examples were inside) with a magnificent structure that should be on the to-visit list of every aviation aficionado.
But the one important aspect of the museum, the one thing that makes it unique among all others with similar collections, has not changed. Aside from those flying suspended from the ceiling, all but a few of of the airplanes on display are within easy reach of the museum’s visitors. Stanchions stand by some airplanes, but no velvet ropes connect them. They stand disconnected to warn visitors that they are approaching something sharp and/or pointy, and to pay attention. (And learning that the F11F-1 Tiger’s wings folded down was one of the many surprises revealed during my visit.) The Navy clearly expects museum visitors to pay attention and respect the small yellow placards affixed to fuselages that say, “Please Keep Off.”
Walking through the timeline of naval aviation history is more like wandering through a clean, well-lighted hangar deck than following a prescribed museum maze. And the rewards are many. It is one thing to read that the wingspan of the Curtiss/Naval Aircraft Factory NC-4, which celebrates the centennial of its historic transatlantic flight next year, is 126 feet, and that the wingspan of the Boeing F4B-4, a frontline carrier-borne fighter during the early 1930s and finished its service as a training airplane in 1941, is 30 feet.
But nothing puts this disparity in perspective more than seeing the fighter under the wing of the flying boat and comparing the wingtip float to the single-seater’s fuselage. For an even greater “holy crap” moment, walk behind the NC-4 and compare the span of its biplane horizontal tail feathers with the biplane span of the Curtiss JN-4 Jenny displayed beneath it. They are almost the same, and the NC-4’s tail looks to have a wider cord. And if you are tall enough, you can peek into the open cockpits. The early biplanes, like the F4B and this Grumman F3F-2, are the most accessible. That tube above the panel that protrudes through the windscreen is the gun sight.
Contemplating the early years of naval aviation, and looking into the aviators’ working spaces, these were surely robust men who were no bigger than the average 21st century middle schooler. Then look at the NC-4’s tail feathers and remember that pure muscle moved these surfaces by direct connections made by cables, pulleys, and pushrods. In today’s aviation era, where an aviator’s inputs are interpreted by a computer and carried out by some form of power steering, I wonder how today’s aeronauts would adapt. Some, perhaps many, would welcome it, because they would be directly involved in the flight. And when you had to hand-crank the retractable landing gear in the F3F and its single-winged offspring, the F4F Wildcat, the effort was so memorable that pilots didn’t forget to raise or lower the gear.
What made it memorable, said my father, who flew the Wildcat for his carrier qualifications on the USS Wolverine in Lake Michigan, was the crank’s location on the lower right side of the cockpit. It took some practice, he said, to fly with your left hand and make the necessary 28 turns with your right and not go phugoid during the effort. — Scott Spangler, Editor