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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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Lake Michigan Training Saves Combat Vets
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If there is a long forgotten annex that has preserved World War II combat veterans for eventual display at the National Museum of Naval Aviation, it is Lake Michigan. Without the inevitable accidents that occur when new naval aviators are learning to land on an aircraft carrier, we would not now be able to look upon the world’s sole surviving SB2U Vindicator torpedo bomber. We could not caress the dive brakes of an SBD-2 Dauntless dive bomber that witnessed the attach on Pearl Harbor, and fought in the battle of Midway. Nor could we gaze at an F4F-3 Wildcat that started its service in September 1941 with Fighting Squadron 5 aboard the USS Yorktown.
They all ended their active service with the Carrier Qualification Training Unit (CQTU) at NAS Glenview, north of Chicago, Illinois. Looking at them today, imbued with the national worship of veterans, some might be critical of the decisions that led to these veterans of the greatest generation spending four of five decades in the depths of Lake Michigan. But the decision-makers of the time were not so constrained. They had a war to fight and win, and that pragmatism overruled all other considerations. And those who appreciate history should thank them for it.
Facing the carrier qualification for thousands of naval aviators and the vulnerability of the ships providing such training in the Pacific, Atlantic, or Gulf of Mexico, training in Lake Michigan seemed the most logical solution. So the Navy put flat tops on two lake steamers and called the result the training carriers Wolverine (IX-64) and Sable (IC-81). Focused on the goal at hand, the Navy certainly expected and planned for training accidents. Probably no one looked to the future and appreciated that, unlike salt water, fresh water does not eat airplanes. It preserves them.
How well is clear on the unrestored patch of painted aluminum on the vertical fin of SBD Dauntless, BuNo 2106. Assigned to the aircraft pool at Ford Island, it survived the attack on Pearl Harbor on December 7, 1941. Then it flew with Bombing Squadron 2 (VB-2) from the USS Lexington (CV-2), taking part in raids on Lae and Salamaua, New Guinea. Then it transferred to the US Marine Corps Scout Bombing Squadron 241 (VMSB-241).
On June 4, 1942, pilot 1st Lt. Daniel Iverson Jr. and radioman-gunner PFC Wallace J. Reid, took off with the other members of VMSB-241 to attack the Japanese carrier Hiryu. BuNo 2106 was one of the few survivors. It returned to Midway with roughly 250 bullet holes in it, a wounded crew, and one working main landing gear. Iverson received the Navy Cross, Reid received the Distinguished Flying Cross, and 2106 got a total overhaul before being assigned to the carrier qualification training unit, freeing up newer aircraft for frontline combat duty.
During a routine carrier qualification flight, on June 11, 1943, a Marine, 2nd Lt. Donald A Douglas Jr., stalled and spun into Lake Michigan, and sank in 170 feet of fresh water. Salvage crews discovered its resting spot in October 1993 and recovered in January 1994 by A&T Recovery for the museum, which restored it. To give visitors an idea of what they started with, the Sunken Treasures exhibit displays an SBD-4 and an F4F-3 Wildcat in pretty much the conditions in which they were found.
The SB2U Vindicator, a two-crew scout bomber, replaced biplanes in the late 1930s and set the stage for its replacement, Douglas’s SBD Dauntless. First flown in 1936, the Navy didn’t order very many, just 58 in 1938 and another 58 in 1940. With a trussed fuselage and largely covered with fabric (construction clearly seen thanks to the open fuselage panels), the airplane was obsolete before the war started, but the Marines fought with them at the Battle of Midway and suffered heavy losses.
The museum calls these aircraft Sunken Treasures, as indeed they are. What’s equally compelling are the number of aircraft still in storage at the bottom of Lake Michigan. — Scott Spangler, Editor
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A Cockpit Crawl into Naval Aviation History
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Am I the only aviator who wants the pilot’s perspective when examining an interesting aircraft? Or am I suffering from unrequired Walter Mitty daydreams? Either way, with a cockpit crawl of more than a dozen aircraft, from the F11F Tiger to the F-14 Tomcat, the National Museum of Naval Aviation is a hangar of dreams in Pensacola, Florida.
Scattered throughout the museum are more than a dozen cockpit procedure trainers (CPTs), which are exactly like fleet aircraft with their wings and most of their fuselages amputated. Each of them taught naval aviators where to find the necessary system information, and what to look for before they made their initial flights in these (mostly) single-seat aircraft.
Climbing into the F-8 CPT during my first visit to the museum in 1972 is a lasting memory because I fit! But I was 5 inches shorter then, so looking to try it (and any others) on was a premeditated goal of this 21st century visit. Seeing the F11F Tiger (above) and the F-4 Phantom CPTs, both in their Blue Angel uniforms, gave me hope that was not disappointed. It has new paint, but I still fit. (Let the day dreams continue!)
While there isn’t any power or instrument life in the CPTs, and the canopies don’t close, but the sticks and rudder pedals (and rudder pedal adjustment cranks) still move from stop to stop. They range from the F11F and T-28, which entered service in the 1950s, to the F-14 Tomcat, which retired from active fleet service in 2006.
Making a cockpit crawl in chronological order is not only a first-hand look at the development of the technology they employ but also the advancement in what test pilots call the “pilot-aircraft interface.” The need for naval aviators to be contortionists clearly diminished over the years.
And then there are anthropometrics, the maximum and minimum measurements that play a large role in which pipeline—jets, helos, or multiengine—is open to a prospective naval aviator. It’s more than just standing and sitting height or buttocks to knee length. They measure every aspect of a prospective aviator’s functional reach, and your arms can be too long (as I found out when trying to reach the switches in the back corners of the Tiger’s cockpit) as well as too short.
The helo cockpits have the most room, with the HH-52 (essentially a single-engine SH-3 Sea King) having much more than the AH-1 Sea Cobra. Subjectively, among the jets, those made by Chance-Vought (the F-8 Crusader and A-7 Corsair II) and Grumman (the F11f and F-14), offered more leg room than those made by McDonnell (the F-4 Phantom) and Lockheed (the S-3 Viking).
The lines of children and adults waiting for the AV-8A Harrier and T-2 Buckeye were a bit longer, and with so much more to see, I didn’t make the time to try them on. Maybe next time. — Scott Spangler, Editor