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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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EFB v. Paper: Weight & Reliability
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In the days before electronic flight bags, the duffels filled with the necessary performance, operational, and navigation paper were a weight and balance line item, especially with a full set of instrument approach plates. When formatted as electrons, all this necessary information weighs no more than the electronic device that stores and displays it.
As EFBs proved their reliability, many pilots reduced the redundant paper they carried on every flight, following the insuccinct guidance found in Advisory Circular 91-78, Use of Class 1 or Class 2 Electronic Flight Bags, which the FAA issued on July 20, 2007. For newcomers and those who might not remember, a Class 1 EFB is a portable electronic device, most commonly an Apple iPad. Class 2 EFB can also be an iPad, but a Class 2 device must be “attached or secured to a permanently installed aircraft mount during use.”
The new EFB guidance, Advisory Circular 91-78A, Use of Electronic Flight Bags, dated February 23, 2024, resolves the redundant paper question. “EFB systems may be used in conjunction with, or to replace, the paper reference material that pilots typically carry in the flight deck. EFBs can electronically store and retrieve information required for flight operations, such as the POH and supplements, minimum equipment lists (MEL), W&B calculations, aeronautical charts, and terminal procedures.”
In all phases of flight, an EFB can replace paper when the information it displays 1. does not replace any system or equipment (e.g., navigation, communication, or surveillance system) that is required by part 91; 2. displays only information which is functionally equivalent to the paper reference material which the information is replacing or is substituted for; 3. the interactive or precomposed information being used for navigation or performance planning is current, up to date, and valid, as verified by the pilot; and 4. the operator complies with requirements of §91.21 to ensure that the use of the EFB does not interfere with equipment or systems required for flight.
Curiously, AC 91-78A makes no reference to the EFB classes mentioned in the superseded AC. That’s because AC 120-76D, Authorization for Use of Electronic Flight Bags, dated October 27, 2017, “Eliminate[d] EFB Classes 1, 2, and 3, and introduce[d] a simpler concept of portable and installed equipment, to harmonize with the International Civil Aviation Organization (ICAO), and to accommodate increasingly complex systems integrating both installed and portable equipment.” It also includes the appendix lists of Type A and Type B EFB applications.
Portable EFBs do not depend on a dedicated aircraft power source or input from navigation equipment to provide display functionality, although they may connect to aircraft power through a certificated power source [but this is always a good idea]; they are not attached to an aircraft mounting device; and are not connected with or receiving data from any aircraft system.
Installed EFBs may receive power from the aircraft that is derived from an electrical bus source protected against short circuits with an appropriately rated circuit breaker or fuse; they may receive position reference from an onboard navigation system, provided such input is designed and integrated in such a manner as to not adversely affect the output of the navigation source to which they are connected; and they may be attached to a mounting device provided that such device is approved for installation into the aircraft (e.g., if intended for installation into a type-certificated aircraft, then such mounting device must meet the requirements of § 21.303.
Portable or installed, the tablet-based EFB is still a single point of failure, which suggests the need for some sort of backup. Many pilots say their smart phones meet this need nicely, and some go a step further by slipping a fully charged power bank and the necessary cables into their headset bag, Others still carry some redundant paper because essential information such as a navigation log and maps for the flight don’t require batteries or a working display to read them. Fire is their only real failure mode, and in that case a pilot has a more pressing problem. Forgetting to bring some sort of backup EFB is another form of failure, but this one is pilot error. — Scott Spangler, Editor
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Climate Change & Preflight Planning
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With climate change continuing the slow and steady march to ever warmer records, 2023 set a new record. (I can hear 2024 softly asking us to hold its beer.) “After seeing the 2023 climate analysis, I have to pause and say that the findings are astounding,” said NOAA Chief Scientist Dr. Sarah Kapnick in a NOAA media release. “Not only was 2023 the warmest year in NOAA’s 174-year climate record — it was the warmest by far. A warming planet means we need to be prepared for the impacts of climate change that are happening here and now, like extreme weather events that become both more frequent and severe.”
Being of a pilot’s mind, the climates have surely made preflight planning increasingly more important and challenging. Avoiding extreme weather is just part of the equation because “extreme” can be much more than stormy. It can also be hot. “The 10 warmest years since 1850 have all occurred in the past decade. In fact, the average global temperature for 2023 exceeded the pre-industrial (1850— 1900) average by 2.43°F (1.35°C),” said NOAA. “Looking ahead, there is a one-in-three chance that 2024 will be warmer than 2023, and a 99% chance that 2024 will rank among the top five warmest years.”
Simply put, if you want to have the safest flight possible, you better refresh and refine your abilities to compute density altitude and apply that information to the latest, most accurate performance data for your aircraft. You don’t want to be like the Ercoupe pilot who rolled off the end of a 5,000-foot midwestern runway when 90 hp wasn’t enough to drag his little bird into the thin 99° air at a field elevation of about 700 feet MSL. The really puzzling part is why he didn’t abort his takeoff attempt after rolling halfway down the runway.
Making sure the aircraft will safely perform in toasty weather is only half of your preflight planning challenge. You must ensure that you are physiologically ready for the flight. Heat stress and dehydration can quickly impede anyone’s thought processes and ability to make reasoned and rational decisions. I learned that lesson in the 1990s on my cross-country return to my Kansas City-area home drome on a triple-digit CAVU day and couldn’t find the single runway airport. Fortunately, I was reviewing a Trimble handheld GPS, and the controller in his airconditioned cab said I was the only heat-addled bozo in the area, so he urged me to follow it until I saw the runway, and then he’d clear me to land. — Scott Spangler, Editor
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Why Don’t Rocket Launchers Pay Airway Trust Fund Taxes?
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Two stories reported near April 1 suggested a cruel prank. Just before 4/1 came news that the FY 2025 budget proposed to raise the per-gallon tax on business jet fuel nearly 400%, to $1.06 per gallon.
As a reminder, aviation fuel taxes are how the government funds the Airport and Airway Trust Fund that pays for airport improvements and some FAA operations such as air traffic control.
Shortly after 4/1, the New York Times revealed America’s commercial space launch operators contribute nothing to the trust fund even though each of the hundreds of rockets they have launched over the years require substantial FAA and ATC involvement.
Rocket launchers like SpaceX are for-profit companies just like the airlines, and they use the national airspace system just like each of the aviation communities that comprise general aviation—so why do they get a free ride?
Perhaps somewhere in the FY25 budget proposal that introduces the five-year fuel tax increase on bizjets will be some sort of equitable tax on rocket launches. And let’s hope that there’s another increase on the taxes paid by commercial airlines, who have an aviation tax deal second only to the rocket launchers.
As the aviation fuel taxes stand now, for all aspects of general aviation, piston flyers pay 0.193 cents per gallon of avgas and kerosene burners pay 0.218 cents for jet fuel. On March 2012, the government added a 14.1 cent per gallon surcharge for fuel burned by aircraft in fractional ownership programs, the majority of which are bizjets.
Regardless of fuel type, commercial aviation operators pay just 0.043 cents per gallon to the Airport and Airway Trust Fund. They also pay a ticket tax, but they certainly build this 7.5% fee into the price passengers pay ride their tubular cattle cars.
And I’m sure they do the same for the per passenger segment tax, defined as the flight between a takeoff and its next landing. Introduced on New Year’s Day 2002, it is indexed with the Consumer Price Index and is $5 in 2024.
By the way, the airline ticket tax does not include all off the fees the airlines so love for baggage, rebooking, legroom, and what have you. For the commercial operator, these fees are pure profit.
So here we are. The rocket launchers are getting free use of an understaffed, overworked air traffic control workforce that must rework and manage the traffic so their missiles can safely puncture the national airspace. And the airlines, which have been reporting substantial profits can add to their bottom lines with untaxed fees passengers pay when the rocket launchers disrupt their travels. And we wonder why our aviation infrastructure is failing us. — Scott Spangler, Editor