-
Making the Brazilian ATR-72 Spin
by
No Comments
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…)
-
How the FAA Let Remote Tower Technology Slip Right Through Its Fingers
by
No Comments
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…)
-
Egyptair 804 Plus Aviation’s Dumb and Dumber
by
No Comments
Egyptair 804 Plus Aviation’s Dumb and Dumber
It’s an old ATC trick … using the word “appears” that is.
Whenever a pilot would ask us tower guys to give their landing gear the once over because of some odd cockpit indication, the airplane would make a slow pass, then wait for an opinion. Using “appears” was a clever way of telling the pilot what we could actually see without extending a guarantee the gear wouldn’t collapse on touchdown because of something we couldn’t.
I first learned about the missing Egyptair A-320 just before bedtime Wednesday night. Out of habit, I checked the local weather in that part of the Mediterranean and noticed nothing unusual before I turned out the lights.
The first reporter called me about 12:15 am wondering if I knew anything. “Sure,” I said. “Doesn’t appear to have been any significant weather along the last few hundred miles of the route.” And so it went the rest of the night every half hour or so on the phone, until one of them could get me in front of a camera for a live update. We didn’t even know about the crazy turns early Thursday morning, of course, so my only options were what appeared to be a possible mechanical failure, explosive device or a highjacking. Not rocket-science of course, but just a couple of years of experience talking early in the game. I figure better for me to give them my two cents than someone who claims it was aliens or something equally goofy.
So I’m still trying hard to figure out what, as the investigation continues building around Egyptair 804, could possibly interest our presidential candidates in commenting on the accident. But no sooner had Thursday’s morning news cycle begun when The Donald tweeted …
Not surprisingly, he made it sound as if he had an inside track to the details, which of course he didn’t.
-
Wings are Next for MAAM’s Black Widow
by
No Comments
Pinned against the hangar wall by a floor-filling mass of airplanes from a B-25 to a Pietenpol, The Mid-Atlantic Air Museum’s P-61 Black Widow restoration project seems unchanged from my last visit in 2014. Wearing its cowled but propless Pratt & Whitney R-28000 engines, it stands patiently on its tricycle gear waiting for its wings.
Those wings, which extend from the port and starboard nacelles, are under construction in another hangar, said Russ Strine, MAAM president. “They are the last big structural item left to do.” While the project’s completion is within sight, there is no predetermine date for the Black Widow’s first flight because the project is funded by donations and much of the work is done by volunteers. But it will fly; rest assured of that.
Working my way through the maze of airplanes on the hangar floor for a closer look, it’s clear to see that the B-25 and P-61 are twin-engine airplanes of similar size. But two engines and a shared weight of 30,000 pounds are where the similarities end. On the floor under the Black Widow’s right 2,000-hp engine was its four-bladed prop. Answering my question about the left side, Strine said, “We now have 2 complete props for the P-61B. The only other airplane to share this same blade and hub is the Curtiss SB2C-5 Helldiver.”
That was a surprise that struck home because my father, a World War II naval aviator, flew the SB2c. It was powered by the Wright R-2600, which is only 200 cubic inches different from the P-61’s engines, so that seemed to make sense.
More surprising was learning that the right engine was a zero-time P-61 QEC. To facilitate a Quick Engine Change, all of the aircraft-specific accessories, fittings, and mounts are already connected to the engine. The odds of such a find for such a rare airplane are incalculable, “but people contact all the time with items,” said Strine.
The top turret of four .50 caliber machine guns is, however, another matter. “Two are known to exist,” said Strine, “and neither owner wants to sell.” Only four Black Widows exist today, and if MAAM can acquire a turret, the museum’s P-61 will not be the only flying example, but the only one with a turret.
Of the 706 examples of all Black Widow variants built, only four are know to exist today. The examples the National Museum of the United States Air Force and the National Air & Space Museum’s Udvar-Hazy Center are related by their service in the post-war Project Thunderstorm. Left at its base after the war, the fourth is at the Beijing Air and Space Museum at Beihang University in Beijing, China.
Ducking under the logo of the 550th Night Fighter Squadron affixed to the MAAM Widow’s nose and sticking my head into the forward cockpit through the door in the nosewheel well, is where most of the work now being done on the airplane is clear. All of the plumbing and wiring is now installed, said Strine, and “we’re just tying up and final detailing the wiring.”
Getting the P-61 Black Widow back in the air is not the only project underway at the Mid-Atlantic Air Museum. The hangar where it now resides “is certainly tight,” said Strine, “but we’re about to remedy that with construction of an additional hangar.” Seeing the fully assembled night fighter is more spacious accommodations is reason enough for another visit to Reading, Pennsylvania. — Scott Spangler, Editor
-
Parachute Museum Is Pioneer Gold Mine
by
No Comments
Jumping from any elevation, even a knee-high footstool, has never been something I have eagerly anticipated, which makes my lifelong fascination with parachutes hard to explain.
It all started in the early 1960s, I think, with my godparents, who fed my existing airplane addiction with a visit to ParaGear (and it’s still in business!), a sky diving shop near their Chicago home. It sold mostly surplus military gear modified for civilian sky divers. The owner answered all of my elementary school questions and gave me a catalog. It was my bible for making GI Joe-sized canopy’s, harnesses, and containers with elastic opening bands, just like those in the catalog, which he tested from ever higher elevations, from trees to a box kite.
Over time my hands-on fascination calmed down to a persistent interest, which led me to the Aviation Trail Parachute Museum, part of the National Aviation Heritage Area in Dayton, Ohio. Filling the better part of the Trail’s visitor center, I didn’t expect to spend all afternoon there, but I didn’t expect it to introduce me to the pioneers who were behind all of the equipment that captured my attention more than half a century ago.
Given his many contributions to aerospace, I’m ashamed to say that I’d never heard of David Gold, in whose honor the Parachute Museum was established. As a 13 year old, Gold was inspired by an exhibition jumper at Queens, New York. He visited local parachute factories and became acquainted with parachute pioneers Floyd Smith and Colonel Edward Hoffman at the McCook Parachute Branch (two more people I need to learn more about).
Gold became a parachute rigger, designer, developer, and fabricator of specialized parachutes for personnel (including patents for a parachute riser system and the “guidable” parachute) and missile recovery systems, including the Apollo spacecraft. Think, for a second, about that last one. Walking on the moon is one thing, but without Gold’s Apollo parachute work…
Among the parachute pioneers I met at the next exhibit, only one—General William “Billy” Mitchell—was familiar. He was behind the McCook Field Parachute Branch, which commenced operations in October 1918. One member of this team, Floyd Smith, a former circus acrobat, race car driver, and test pilot, made a radical proposal, pilots should wear the parachute, not be connected to one mounted in the airplane, which would allow the airman to open the chute once clear of the airframe. This was radical because in those early days, everyone believed that freefall was a sure cause of unconsciousness.
Harold Harris was the first to save his life with McCook’s freefall parachute when he bailed out of malfunctioning Loening PW-2A monoplane. He landed at 403 Valley Street in Dayton, and when his rescuers reached him, he said, “I’m not hurt, just excited.” I’ll say. Besides preserving his life, Harris became the inaugural member of the Caterpillar Club, named for the insect that spun the silk fiber used in early parachute canopy’s. Membership is earned by employing a freefall parachute when an aircraft ceases safe operation. By the 1950s the club had more than 80,000 members, including Charles Lindbergh, General Jimmy Doolittle, President George H.W. Bush, and two Ohio boys, John Glenn and Neil Armstrong.
For dessert, the Parachute Museum served two succulent morsels of aviation trivia. First, most aviation geeks know that Operation Paperclip was the U.S. operation that scooped up the German rocket scientists who were the foundation of the U.S. space program. Paperclip also brought German’s top parachute designers to the United States, and most of them, went to work at Wright Field’s Parachute Branch Equipment Laboratory. And they tested their new designs in a vertical wind tunnel (who knew?), built in 1945 and still in use today. And a vertical wind tunnel might be the only way I’ll ever willingly experience freefall. But if I’m wearing a chute in a plane that breaks… — Scott Spangler, Editor