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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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Book Review: Empires of the Sky
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A Concise Look at Human Flight with an Unexpected Focus
With my knowledge bank bereft all but the most rudimentary information about Zeppelins (aka rigid airships), my curious eye immediately focused on the tail end of the Zeppelin under the title, Empires of the Sky. (Following the airship to the backside of the dust cover identified it as the Graf Zeppelin.) The subhead of Alexander Rose’s 600-page tome—Zeppelins, Airplanes, and Two Men’s Epic Duel to Rule the World—lured me between the covers.
I assumed that German Count Ferdinand von Zeppelin, the eponymous airship’s creator, might be one of them. Or maybe it was Hugo Eckener, who turned them into a reliable form of air transportation (at least until the Hindenburg arrived at Lakehurst, New Jersey, on May 6, 1937). But who was the other? It was someone I would have never considered—Juan Trippe, of Pan American Airways.
This at first seemed an odd couple, but as I read, it was a genius paring because both men were pursuing the same goal, to provide reliable transatlantic air service. And it provided an important perspective, refocusing my grouping of things that fly and things that do not. Rose set the stages for his book by sharing Octave Chanute’s concise explanation of the two camps hoping to solve the problem of flight more than a century ago.
Writing Aerial Navigation in 1891, Chanute’s two competing schools were addressing the challenges of flight:
“1: AERONAUTS, who believe that success is to come through some sort of balloon, and that the apparatus must be lighter than the air which it displaces.
“2: AVIATORS, who point to the birds, believe that the apparatus must be heavier than air, and hope for success by purely mechanical means.
“Curiously enough, there seems to be very little concert of study between these two schools. Each believes the other so wrong as to have no chance of ultimate success.”
Rose starts with the aeronauts, because they flew first. In elegantly crafted prose, he brings aerostat novices up to speed on the contributing experimenters and the technological contributions. And then he reveals an elegant surprise. Ferdinand Zeppelin made his first flight in a tethered balloon in St. Paul, Minnesota, on August 19, 1863, with one Professor Steiner, late of the Union balloon corps. A military officer, Zeppelin witnessed balloon mail from Paris in 1870, during the Franco-Prussian War.
Four years later, following a fall from his horse, he awoke from a “fevered dream” in which he saw the flimsy predecessor of what would become his eponymous Zeppelin, so named by his volunteer PR man, Hugo Eckener, who went on to take over the company following Zeppelin’s death. Rose evenly balanced the human aspects of the story with the technological side that ranged from the development of the rigid air ships and their duralumin metallurgy to their military service during World War I.
Empires of the Sky also takes an illuminating look at American airship efforts and their ties to Germany. And Rose devotes an equal measure of research to the camp of aviators. Here I found fewer rewarding surprises, but there were a good number of them. Most of them told the Pan Am story, how it developed its flying boats and established its Pacific and then Atlantic routes. While I can appreciate what Trippe and Pan Am achieved, I learned that how he achieved them would hold him in good stead in the cutthroat, backroom backstabbing corporate culture of the 21st century.
Whether you lean toward Team Aeronaut or Team Aviator, or you are interested in learning more about them and how they came to be, Empires of the Sky is a rewarding and worthwhile investment of your time. I do have one caveat, however, don’t start reading it after dinner when you have to be at work the next morning. — Scott Spangler, Editor
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Inattentive Oshkosh Migrants Will Find No EAA Roosts at Wittman in July 2020
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It is a statistical reality that regardless of the methods of dissemination, roughly 10 percent of the population will not get the word. Or they will forget they got the word and reflexively follow their atavistic inclinations. Some creatures, like the swallows who migrate to San Juan Capistrano every spring from their winter residences in Argentina, don’t have a choice because conscious decision making is probably not among their sentient capabilities. Pilots don’t have this excuse, and those who migrate to EAA AirVenture Oshkosh this July will find no roosts at Wittman Regional Airport.
In an attempt to catch the attention of pilots who were not paying attention, or might forget that EAA CANCELED AIRVENTURE 2020, Wittman Regional Airport posted this notice on its website and sent an email to everyone on its mailing list.
AIRPORT STATUS DUE TO CANCELLATION OF 2020 EAA AIRVENTURE
We’re all disappointed with the cancellation of EAA AirVenture Oshkosh 2020, as it means so many different things for everyone who attends. For thousands of aviators, flying to Wittman Regional Airport (KOSH) is a highlight in the logbook.
As AirVenture 2020 is not taking place, Wittman Regional Airport will operate normally as a public use airport with contract tower services. For those considering flying to Oshkosh in late July, it’s important to manage expectations about what is permissible:
- *Aircraft parking for itinerant traffic is available on the Terminal / Basler FBO Ramp. No permit has been obtained for aircraft parking or camping on any turf areas of the airfield and therefore is not permitted.
- *No buildings or facilities on the AirVenture grounds will be open. Those attempting to camp will be asked to move to Terminal / Basler FBO ramp parking or depart.
- *The Warbird / Homebuilt camping areas near P-1 taxiway will not be open. Papa 2 taxiway (Boeing Plaza) will not be accessible.
- *There will be no access to EAA facilities from the airport. EAA did not obtain a Wisconsin temporary campground permit for Camp Scholler in 2020, so it is illegal to accept or allow campers there this year. The EAA Aviation Museum also will be closed to the public through July.
For those who still want to fly to Oshkosh during AirVenture week, we encourage you to park at the Terminal / Basler FBO ramp, stay at one of our local hotels, and enjoy some of Oshkosh’s hospitality. Please coordinate with Basler Flight Service to arrange any ground handling needs.
And if you’re thinking of flying in for a visit, following the operational items in the OSH message, make sure you add the Covid-19 status to your preflight planning. It seems that Oshkosh, for the past few days, has been leading the state in new cases, especially among 20 and 30 year olds. Who knows what it will look like in July?
And for the 10 percent who didn’t get the word, EAA is hosting a safer, more economical replacement for your annual Oshkosh migration with a virtual celebration, EAA Spirit of Aviation Week, July 21-25. I’ll be there, but on my trips into town during the week, I may swing by Wittman Field to see who didn’t get the word. — Scott Spangler, Editor
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Crew Dragon Demo 2: A Short Course in 21st Century Spaceflight
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As it did when Alan Shepard kicked off the US Space program with his suborbital flight in 1961, I eagerly anticipated watching the program’s most recent chapter, the resumption of flights launched from American soil. Watching the preparations for the Demo 2 departure of Crew Dragon on Wednesday and on Saturday was much more than I expected, a short course in 21st century spaceflight.
Used to the military-toned phraseology employed during all of the NASA launches I’ve watched since Shepard went flying in 1961, it was clear this was a commercial operation because everyone on the NASA TV Launch America referred to everyone involved by their first names. Watching the launch on Saturday with my sister and brother-in-law, we considered (briefly) starting a drinking game where we had to take a sip every time someone said “Bob and Doug,” referring to the Crew Dragon crew of Bob Behnken and Doug Hurley. Thankfully we didn’t. If we had, the four of us would have been sleeping it off under the TV long before Bob and Doug closed their helmet visors and armed the launch escape system so they could start filling the Falcon 9 with densified LOX and RP1.
Like the NASA flights that preceded it, acronyms and multi-letter abbreviations liberally seasoned the comments and conversations of launch communications. What I did not expect, based on this past experience, is that the Launch America crew would translate and explain—in English—what they were talking about, hence the much appreciated short course in 21st century space flight.
Chances are you were, like me, one of the more than 10 million online viewers, so I won’t bore you with a geek-worthy catalog of new learning. But as a sample, the super turbo pumps feed the Falcon 9’s nine Merlin engines a mixture of densified liquid oxygen, which is colder than traditional LOX to provide more oxidizer in the same volume, and Rocket Propellant 1, which is a rocket-grade kerosene. To “complete the fire triangle,” the Falcon 9 adds TEA-TEB—a mixture of triethylaluminum and triethylborarne—a pyrophoritic compound that spontaneously combusts when exposed to oxygen (gaseous or liquid or densified liquid).
What they did not explain is why the crew kept their helmet visors open until arming the launch escape system. I remember from spaceflights previous when the crew had to prebreathe oxygen to purge their system of nitrogen before launch, to prevent any chance of bubbles of that gas in their bloodstreams should the spacecraft lose pressurization on its way to orbit. (Anyone have any ideas?) The boldly numbered members of the ground crew, on the other hand, seem an efficiently brilliant way to assigning and keeping track of their essential duties, responsibilities, and contribution to the flight.
If Launch America discussed the roots of the whimsical equipment names, I missed it, so I had to do some post flight research. SpaceX founder and chief engineer Elon Musk is a science fiction fan (like that was a surprise), so he named his reusable rocket after Hans Solo’s Millennium Falcon. Elon explained the capsule’s moniker in a Twitter response to a question about its name. The reusable capsule “was originally called Puff the Magic Dragon, as people said I was high if I thought it would work, so I named it after their insult.”
Expecting the Falcon’s Merlin engines to be named after King Arthur’s wizard, I discovered it was named after the bird, as were SpaceX’s other engines, Kestrel and Raptor. The drone ships that are the landing pads for the Falcon’s first stage were a bit more esoteric. Of Course I Still Love You and Just Read the Instructions are the sentient space ships in Ian M. Banks’s science fiction novel, The Player of the Games.
Taking notes during this enthralling short course was beyond difficult because I could not avert my eyes from the stunning HD video from almost every conceivable angle. Given technology today, I should not have been surprised, but my visual memory was stuck in the shuttle era. But some commercial aspects remain unchanged. On Saturday we turned into the Discovery Channel, and we greatly enjoyed the program that recounted the history of SpaceX and all of its successes and failures. But when the announcer announced the celebrities, including Katy Perry, who would be part of the launch coverage, we switched back to NASA TV and Launch America.
On Launch America the countdown conversation held us rapt, until one of the astronauts uttered a trite cliché, “Let’s light this candle.” Really? The Mylar Puff the Magic Dragon that floated up beside of the seats, described as the zero-g indicator, helped make up for the cliché, and trying to keep up with the speed and altitude readouts, in meters per second and kilometers, quickly buried the B-movie quote in 21st century appreciation and amazement. — Scott Spangler, Editor