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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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Jetwhine Loses a Friend
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I started Jetwhine 13 years ago amidst breaking news of an Embraer Legacy biz jet having collided in midair with GOL airlines Boeing 737 over the Brazilian jungle. A few years later my friend Scott Spangler joined and since then, we’ve worked hard to tell aviation stories in a way readers couldn’t find anywhere else.
There was another member of the team that only a few people who had ever visited Camp Jetwhine over the years came to know personally; my friend Dan Webb from the Airplane Geeks podcast knew him, as did Steve Vischer and Grant McHerron from the Plane Crazy Down Under podcast, plus a few more.
This week our unsung office mascot left us and left me wondering, “What is the Value of a Friend?” I hope you’ll indulge us this one time with a non-aviation essay. Thanks, Rob Mark
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I lost a friend last week, a good one. It wasn’t really a surprise, yet there was that inevitable flutter up to the emergency before the last breath of course, when there was no time to think, only adrenaline coursing through my veins driving me to do something, anything … even though deep inside I knew nothing would help.
When I saw our big hound dog Simba on Friday morning, I knew the end was close.
Already diagnosed with a weak heart valve and a thyroid problem, his breathing was rapid and labored. His arthritis no longer allowed the big guy to support even is severely diminished weight; it was impossible not to grieve. Hell, I’d been grieving already for weeks.
Thirteen years ago, he was an impressive 110-pound Rhodesian Ridgeback, with big meaty paws the size of my clenched fist and a bark deep enough to frighten even the bravest salesman from our front door. The local beat cops told we didn’t need a burglar alarm.
Even as a puppy I realized he was clever and funny, if not a bit bossy at times. When he was on a leash he loved most people. He’d stop for almost anyone he thought might realize how impressive a dog he was. When they drew near, he’d lay down on his side looking hurt, which of course made people stop … even passing cars. A local cop once offered to drive us to the vet for help, until she realized all he really needed was a tummy rub. Simba knew most of the suckers in our neighborhood.
He did have a fatal flaw. I’m sure he must have been sired by goats because he was the most stubborn animal I’ve ever met. At morning walk time, even with the leash already attached, he simply refused to leave the house by the back door; only the front door would do. And 110 pounds of resistance was too much for me. If he wanted a left turn at the corner, suggesting a right was a waste of time. And if he spied a rabbit or a cat, all bets were off. I learned quickly when to let go of the leash.
But he was my friend, a guy who traveled to work with me every day and never missed a single one, until his last week on earth. We’d talk to each other at work when we had something to say, him often more than me. He needed more water, more food, another walk. I never could figure out how he knew when it was 3 o’clock each afternoon. He did have limits though. I’d run story ideas past him and he’d just cock his head with a look like, “What in the Hell are you talking about?”
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Runway Numbers and a Mobile Magnetic North Pole
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Releasing a new World Magnetic Model (WMM) was one bit of work that didn’t get done during the partial shutdown of the U.S. Government. It finally saw the light of day on February 4. But that’s not the important part. The important part is that the position of magnetic north has moved so much they had to update the WMM a year early. If you remember your ground school lessons about runway numbers, the headline should make sense, and you know why some runway numbers will be changing.
Magnetic north doesn’t move so much as wander, as the NOAA chart above clearly shows. In stories about the early WMM update (the first time it has ever happened), the New York Times said English mathematician Henry Gellibrand discovered its movement 400 years ago, and the line in the chart starts in the year 1630. More accurately, he discovered magnetic declination (or variation), the difference between true north and magnetic north.
As reported by NOAA and the National Geographic, Sir James Clark discovered the geographic position of magnetic North Pole in northern Canada in 1831. Since then, it’s been making its way north to Siberia. The dot at the end of the dotted line is its 2019 position, and if you want to see it move with history, check out the NOAA Historical Magnetic Declination map. NOAA and the British Geological Survey developed the WMM, and scientists periodically compare its accuracy with ground and satellite magnetic data observatories. In 2018, the difference exceeded the acceptable limits, leading to the early WMM release.
The WMM’s five-year timetable parallels the FAA’s periodic check of runway headings. Given what’s involved, logic suggests that we’ll not see wholesale runway renumbering. For one thing, the new magnetic north pole will not affect all of our takeoff and landing places. Going back to those ground school lessons, a runway designation must change when its heading is off 3 degrees or more.
Given the FAA’s runway rounding rules, this will predominately affect runways whose heading cross the 5-degree midline. If a runway’s heading changes from 254 degrees (rounded down to Runway 25) to 257 degrees, it must step up an become Runway 26. The lucky runways will have a heading that steps up or down to the 5-degree midline, because they can round up or down, meaning they employ the existing designation.
On the surface, changing a runway’s number seems simple, but it involves way more than paint and new airport signs (which in themselves are not cheap). It is a coordinated effort that involves everything from the Airport/Facility Directory to VFR and instrument charts and those for every approach to that runway. And making sure the runway designation and its magnetic heading match as required matters, if for no other reason that matching it with the cockpit compass reconfirms to pilots that they are on the right runway. — Scott Spangler, Editor
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Airport Circular is Wildlife NIMBY Guide
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Officially, the FAA is seeking comments by February 28 on its draft Advisory Circular 150/5200-33C, Hazardous Wildlife Attractants On or Near Airports. After reading the 37-page document, here’s a shorter and more concise title, Wildlife NIMBY Airport Guide.
It includes a diagram with the recommended backyard proximity (separation distances) for airports that serve piston aircraft (any airport that does not sell Jet-A) and those that serve turbines. At a piston airport, the minimum separation from any NIMBY wildlife attractant (as discussed in the AC’s second chapter) like a MSWLF (that would be a Municipal Solid Waste Landfill) is 5,000 feet. It’s double that at a turbine airport.
The AC really isn’t that much different from the one it is replacing. The draft consolidates and reorganizes its discussion of land uses on and near airports that attract wildlife and updates wildlife evaluation and mitigation procedures. (If you’re curious about the details, follow the link above and have a read.)
More importantly, it emphasizes that wildlife NIMBY is important to all airports, public or private, GA or commercial. To critters, any airport is open space, a refuge from the sprawling civilization that’s overtaken its habitat. How the airfield is or is not certified and who it serves matters not to them. But it will matter to the human in an airplane that runs into one of them.
Another change relates to the damage a critter collision can cause. The FAA moved the table “Ranking of Hazardous Species” to AC 150/5200-32B, Reporting Wildlife Strikes. Every aviator should carry a copy of it in his or her flight bag because it not only explains when and how to make a report, it includes a report form, which is a handy way to record all of the necessary details right after the strike, assuming you’re not on the way to a hospital.
The FAA distilled the wildlife table from its database of reported strikes. There are 50 critters on the list, and all of them have at least 100 strike reports. Using these reports, the FAA derived a composite ranking based on damage (unknown, minor, substantial, destroyed), major damage (anything that affected aircraft structural strength, performance, or flight characteristics and would require major repair or component replacement), and strike’s effect on flight (aborted takeoff, engine shutdown, precautionary landing or other negative effect on flight).
First on the list is the white-tailed deer, with a mean hazard level of 55 and a relative hazard score of 100. The next four-legged critter on the list is the coyote, No. 12, preceded by birds, include the snow goose, turkey vulture, Canada goose, sandhill crane, bald eagle, mallard, great blue heron, and American coot. More birds separate the coyote from the red fox, tied for No. 23 with the snow bunting (above).
The next four-legged critter is the woodchuck at No. 32. The striped skunk is last on the list. All of its damage scores are zero, but there’s no mention of the lasting aroma. With so many birds on the list, the AC kindly points out that 78 percent of bird strikes occur at 1,000 feet or lower and that 90 percent occur below 3,000 feet above the ground.
As it is with aircraft traffic, see-and-avoid also works with critters—if you know what to look for. To learn what attracts them, give this draft AC a gander. To further feed your autodidactic critter curiosity, dive into the FAA pages on Wildlife Hazard Mitigation and Wildlife Management. — Scott Spangler, Editor