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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.
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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Flying Models & Aviation’s Next Generation
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If puzzled by present options for your descendants‘ Christmas morning surprises, might I suggest a flying model. Regardless of their age, it may instill a lasting interest in aviation and teach them how to figure things out as they mature, if you’re there to guide them with focused questions.
The example given here are from my childhood and my continued hands-on model flying with my sons, and now, with my grandsons. (I’d include daughters and granddaughters if the Spanglers had any.) The key is to be hands on, and for the recipient of aviation’s gift to figure things out for themselves and, later, to repair the consequences of their learning experiences.
It starts with the ubiquitous balsa glider, often available free at aviation trade shows as marketing giveaways. The joy of finally configuring it for a long, steady glide is ageless, but the lessons can start when you’re halfway to 10. Every flight is a learning experience. When a flight comes to an unhappy end, ask the pilot why that might be. What pieces of the glider are missing, broken, or misaligned?
Questions are the key to building interest, curiosity, and problem-solving skills. If that glider moves through the air, what do you think the fins on its tail end do? Why is the slot for the wing longer than the wing’s chord. What do you think happens if you move the wing forward or back? Let’s try it and find out.
When these glider pilots reach their first decade, it’s time to add some power. Half-A, or .O49, is a good place to start. Stifle your personal remote control (R/C) technological wants and desires and go control line (CL). The important lesson here is that pilots can see their connection to the airplane they control. They can see the lines that run from the handle in their fist to the bell crank and pushrod that controls the model’s elevator.
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Seeing the Future of Aviation in the Past
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With its back to the coastal mountains of Oregon, the world’s largest free span wooden hangar sleeps like a giant on green grass under a rusty blanket of tin. Known as NAS Tillamook Hangar B, it is the sole survivor of the 17 wooden hangars the U.S. Navy built on the West Coast in 1942 to protect K-class blimps when they weren’t flying anti-submarine missions. On closer reflection, its past suggested the future of aviation.
Its alphabetical predecessor, Hangar A, was built second, in 27 working days, in 1943. What makes this feat remarkable is the hangar’s size: 1,072 feet long, 296 feet wide, and 192 feet high. It covers more than seven acres, and each hangar held up to a half-dozen K-ships, which were 252 feet long and 80 feet in diameter. At each end, concrete stanchions support the 120-foot-high six-section doors that moved on railroad tracks to a 220-foot wide yawn.
The stanchions and the concrete footers for the wooden arches that supported the tarpaper and tin roofed structure are all that remain of Hangar A. It burned in 1992. To offset some of hangar’s $20,000 monthly upkeep, it rented some of its seven acres as storage, and it was 7,600 tons of straw awaiting shipment to Japan that caught fire. The straw, worth about $200,000, was insured. The hangar, owned by the Port of Tillamook Bay, was not.