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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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B-17 Concrete Ordinance? The Disney Bomb
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YouTube is a good weekend destination when the wind chill is in double digits because it usually inspires a curiosity quest. It started with The Doc Furness War, a 96-minute aggregation of 16-mm color motion pictures taken by the flight surgeon of the 92nd Bomb Group based at Paddington, UK. If you’re curious about life at a World War II B-17 base, this one covers all aspects of life, from passes to London to flying combat missions (with none of the Memphis Belle film you see in so many other productions).
The narrator does an excellent job of expanding the moving images with detailed words. He explained, for example, that the long, pointy cylinders the crews were mounting below the B-17’s wings, one on either side of the bomb bay were “Disney Bombs.” A US Army Air Pictorial Service film said General Doolittle’s men called it the “Disney Swish.” The B-17s dropped the 18-foot bombs on hardened targets like submarine pens and rocket sites.
So what’s the connection to Disney? And is that Mickey Mouse’s Disney? Apparently, the weapon was inspired by the bomb that took out a Nazi sub pen in a propaganda film, Victory Through Air Power, made by Walt Disney.
But wait, the story is even more unexpected. A Royal Navy officer, Captain Edward Terrell, who served in the Royal Naval Volunteer Service with the Directorate of Miscellaneous Weapons Development, imagined the weapon, officially known as the “4500-pound Concrete Piercing/Rocket Assisted” bomb. The solid-fuel rocket boosters gave it the added Swish to penetrate 16 feet of solid concrete. Gravity alone accelerated the Britain’s 10,000-pound Tallboy bomb to 750 mph. The Disney hit at 990 mph.
Built in three sections, the thick armor piercing steel warhead was 11 inches in diameter and filled with 500 pounds of explosive. The center section, 19 inches in diameter, held 19 3-inch rocket motors. The tail section held the necessary electrical circuits and wind-powered generator fan blades. A time delay or barometric sensor ignited the rocket motors, and the bombers had to drop the rocket-accelerated weapons precisely from predetermined altitudes.
In other words, the Disney Bomb rarely hit its intended targets. And this explains why the British bomber command, which usually practiced area bombing at night, never launched a Disney bomb. Believing the Army Air Forces claims of its daylight bombing accuracy, founded on the Norden bombsight, the British joined forces with Doc Furness’ outfit, the 92nd Bombardment Group.
During a March 1945 raid on submarine pens under construction at the port of Farge, not far from Bremen, 30 B-17s launched 60 Disney Bombs. One of them hit the target. Given this success rate, Disney development ended not long after the war. Clearly, all it needed was the GPS guidance system used on today’s Joint Direct Attack Munitions (JDAMs). In 2009, the 8th Air Force scored another hit when the body of a Disney Bomb, and its 500-pound warhead, were extracted from the thick concrete roof of a bunker in Watten, a V-2 launch bunker, now a private museum.
If you enjoyed this story, why not SUBSCRIBE to JetWhine, if you haven’t already, and please share it with anyone who might find it interesting. — Scott Spangler, Editor
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Crowdsourced SciFi Dictionary is Time Travel Gateway
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As a word merchant, dictionaries are my favorite books whether they are online or old school paper, and not because I am a less than stellar speller. The most fascinating are historical dictionaries, like the Oxford English Dictionary (OED), that trace a word’s life from its birth of first usage through its lexical and linguistic maturation. Words cannot describe my joy at discovering the new Historical Dictionary of Science Fiction (HD/SF), because the aerospace endeavors we today take for granted were considered science fiction not that long ago.
Its editor, I learned, is Jesse Sheidlower; he started this ongoing project when he was an editor at large at the OED. No longer formally affiliated with the OED, this work in progress continues to illustrate the core vocabulary of science fiction and related fields. Like the OED, the HD/SF employs crowdsourced research. (For an entertaining and informative explanation of how this process evolved, read The Professor and the Madman by Simon Winchester or watch Mel Gibson and Sean Penn in the title roles in the 2019 film on Netflix.)
As a work in progress (no dictionary is ever finished because our lovely language never stops evolving), the HD/SF is still collecting verifiable evidence in the form of quotations from printed sources. The site also seeks moderators who are dedicated science fiction and detail geeks who will actively edit its content. If this is you, check out How to Help.
Aside from the words that live in the dictionary, what makes it a worthwhile read is the many ways into it. One way is by subject, from Aliens and Dimensions to Propulsion and Weaponry. Or you can look at the list of Most Quoted Authors, starting with Robert A. Heinlein, with 178 quotations. For a quick read, the menu offers New Entries (since site relaunch), today topped by “Afrofuturism n. (1993)” defined as “a movement in literature, music, art, etc., featuring futuristic or science fiction themes which incorporate elements of black history and culture.”
If you like surprises, select the Random Entry menu item. F.M. Allen introduced The Little Green Man as the title of his book, published in 1895, the debut of “a stereotypical inhabitant of our space; a person of peculiar appearance.” Naturally, you can search the dictionary by headword and author. Or you can do what I did this weekend, watch it snow and scroll through the HD/SF’s 35 pages.
Aerocar is the word that hooked me. The image the word brings to mind is Molt Taylor’s post-war flying car, which first flew in 1949. But I learned that Fred C. Smale introduced the word in a story he wrote in 1900 for Harmsworth Magazine, the “Abduction of Alexandra Seine.” And you can read it by clicking the “page image” button, and find the passage. “Bowden Snell was now developing the film in his room at the Flash office, and the aerocar which had brought him was still outside the large bay window swinging gently to and fro at its moorings in the summer breeze.” That sounds like urban air mobility to me.
If I haven’t already, I’ll stop here before I exemplify Sturgeon’s Law. Based on a statement by Theodore Sturgeon in the early 1950s, it wasn’t quoted as a humorous aphorism that maintains that 90 percent of a body of published material or knowledge is worthless, “usually later cited as 90 percent of everything is crap.”
If you enjoyed this story, why not SUBSCRIBE to JetWhine, if you haven’t already, and please share it with anyone who might find it interesting. — Scott Spangler, Editor
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Why Student Pilots Shouldn’t Carry Passengers
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Good pilots become better pilots with experience. One of an aviator’s top hurdles on the way to gaining the best experience is becoming a practical risk manager. When does a flight make sense considering the fuel available, the cargo, the weather, the time element and a few other concerns? And when is a flight a bad risk for many of the same reasons, or to put it more bluntly, when do some flights simply represent a stupid risk?
Like the advice most parents offer their teenagers about late-hour adventures, especially when they’re behind the wheel of a vehicle, nothing good ever seems to happen in the middle of the night. Sadly, that applies to flying too as the NTSB explained in a recent preliminary report of an accident that occurred on December 16, 2020, near Bossier City, Louisiana.
Photo courtesy of FlightAware The pilot of a PA-28 — N55168 — departed Shreveport Downtown Airport (DTN), Louisiana at 4:17 am when the local weather was reported as a 600-foot overcast and 10 miles visibility making the airport IFR. The pilot, however, was not instrument rated. Per the NOTAM, Downtown Tower was also not staffed at the time the aircraft departed. The airplane crashed about 20 minutes later at 4:35 am claiming the life of the pilot and the single passenger on board. The preliminary report offers a couple of insights into what might have been going on in the pilot’s mind that morning.
But this strange early-morning adventure turned reckless when the report noted pilot possessed only a student pilot certificate at the time of the accident. Student pilots are, of course, prohibited from carrying passengers at any time. So, what in the world spurred this aviator on to make a flight when so many issues were already conspiring against him and his passenger?
An airport security video and records show that DTN’s pilot-controlled lighting (PCL) was activated at 0412 and an airplane departed Runway 14 at 0417 squawking a VFR 1200 code. Nearby Shreveport TRACON (SHV) controllers saw the target appear on their radar at 0418.
The Piper flew an irregular flight path headed east after takeoff, but the airplane seemed to pause to maneuver over Barksdale Air Force Base (BAD) for most of the remaining time it was airborne, perhaps for a little sightseeing excursion? The area around the Air Force Base is dotted with obstacles that reach between 500 and 800 feet AGL. A low cloud deck with 10 miles of visibility would at least have helped the pilot see some of these obstacles if they were looking. An SHV approach controller called the air base control tower to let them know the Piper was flying overhead between 600 and 1,800 feet MSL. Believing the airplane might be experiencing an emergency of some kind, the Barksdale controller cranked up the base’s runway lights to full brightness and tried unsuccessfully to contact the pilot by radio.
Late in the flight, radar showed the airplane in a left descending turn before all data ended at 0439. The airplane impacted a remote, wooded terrain on the air base’s property during which the left wing completely separated from the fuselage and the right wing partially so. Most of the airplane was crushed during impact which meant the two people aboard must have died instantly.
When the NTSB reviewed the CFI’s records related to the student pilot, they showed the instructor had endorsed the student about a month before the accident to fly locally in the DTN traffic pattern, but only with the instructor’s express approval before each flight. The instructor also emphasized to the pilot that they were never allowed to carry passengers. The student pilot never contacted the instructor before the December 16 flight. This first NTSB report did not indicate any conversations the instructor might have had with the NTSB about this student’s state of mind.
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