air traffic control

8 Articles

All-Band Receiver Lets You Listen To All The Radio At Once

January 9, 2025 by 52 Comments

There are many ways to build a radio receiver, but most have a few things in common, such as oscillators, tuned circuits, detectors, mixers, and amplifiers. Put those together in the right order and you’ve got a receiver ready to tune in whatever you want to listen to. But if you don’t really care about tuning and want to hear everything all at once, that greatly simplifies the job and leaves you with something like this homebrew all-band receiver.

Granted, dispensing with everything but a detector and an audio amplifier will seriously limit any receiver’s capabilities. But that wasn’t really a design concern for [Ido Roseman], who was in search of a simple and unobtrusive way to monitor air traffic control conversations while flying. True, there are commercially available radios that tune the aviation bands, and there are plenty of software-defined radio (SDR) options, but air travel authorities and fellow travelers alike may take a dim view of an antenna sticking out of a pocket.

So [Ido] did a little digging and found a dead-simple circuit that can receive signals from the medium-wave bands up into the VHF range without regard for modulation. The basic circuit is a Schottky diode detector between an antenna and a high-gain audio amplifier driving high-impedance headphones; [Ido] built a variation that also has an LM386 amplifier stage to allow the use of regular earbuds, which along with a simple 3D-printed case aids in the receiver’s stealth.

With only a short piece of wire as an antenna, reception is limited to nearby powerful transmitters, but that makes it suitable for getting at least the pilot side of ATC conversations. It works surprisingly well — [Ido] included a few clips that are perfectly understandable, even if the receiver also captured things like cell phones chirping and what sounds like random sferics. It seems like a fun circuit to play with, although with our luck we’d probably not try to take it on a plane.

How Three Letters Brought Down UK Air Traffic Control

September 13, 2023 by 51 Comments

The UK bank holiday weekend at the end of August is a national holiday in which it sometimes seems the entire country ups sticks and makes for somewhere with a beach. This year though, many of them couldn’t, because the country’s NATS air traffic system went down and stranded many to grumble in the heat of a crowded terminal. At the time it was blamed on faulty flight data, but news now emerges that the data which brought down an entire country’s air traffic control may have not been faulty at all.

Armed with the official incident report and publicly available flight data, Internet sleuths theorize that the trouble was due to one particular flight: French Bee flight 731 from Los Angeles to Paris. The flight itself was unremarkable, but the data which sent the NATS computers into a tailspin came from two of its waypoints — Devil’s Lake Wisconsin and Deauville Normandy — having the same DVL identifier. Given the vast distance between the two points, the system believed it was looking at a faulty route, and refused to process it. A backup system automatically stepped in to try and reconcile the data, but it made the same determination as the primary software, so the whole system apparently ground to a halt.

It’s important to note that there was nothing wrong with the flight plan entered in by the French Bee pilots, and that early stories blaming faulty data were themselves at fault. However we are guessing that air traffic software developers worldwide are currently scrambling to check their code for this particular bug. We’re fortunate indeed that safety wasn’t compromised and only inconvenience was the major outcome.

Air traffic control doesn’t feature here too often, but we’ve previously looked at a much earlier system.

Header image: John Evans, CC BY-SA 2.0.

It’s A Bird! It’s A Plane! It’s… A Live Air Traffic Plane Spotting Simulation

July 12, 2022 by 5 Comments

Plane spotting has been a hobby of aviation enthusiasts for generations. Hanging out by the airport, watching aircraft come and go, maybe even listening to Air Traffic Control on a scanner from your local Radio Shack. Yep- we’ve been there, and it can be a lot of fun! But how can those of us who don’t live near a major controlled airport keep up on the action? As demonstrated by the [Information Zulu] YouTube channel’s Live Stream, seen below the break, the action may be closer than you think!

Aircraft on approach to LAX- Virtually

By using publicly available information, software, and some ingenuity, [Information Zulu] has created a live simulation of Los Angeles International Airport (LAX) for your simulated plane spotting pleasure. Aircraft positional data is gained through an ADSB receiver and piped into a the flight simulator software with a Traffic Injection Addon, and the simulator itself is used to properly place aircraft, set the weather, and even the correct aircraft types and liveries. Setting off the illusion of a real plane spotting adventure is the live Air Traffic Control radio chatter!

We love the creativity that went into not just making all of the software available, but in combining it into a cohesive product that can be viewed 24/7 on YouTube that, if you squint just right, could be mistaken for a view of the real thing.

If you’re not familiar with ADSB and how it’s used to track aircraft in such a way that anybody can receive it with the right equipment, check out this beginner’s course on ADSB from a few years back!

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Wind Farms In The Night: On-Demand Warning Lights Are Coming

March 24, 2020 by 117 Comments

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

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Wing Opens The Skies For Drones With UTM

May 20, 2019 by 7 Comments

Yesterday Alphabet (formerly known as Google) announced that their Wing project is launching delivery services per drone in Finland, specifically in a part of Helsinki. This comes more than a month after starting a similar pilot program in North Canberra, Australia. The drone design Wing has opted for consists not of the traditional quadcopter design, but a hybrid plane/helicopter design, with two big propellers for forward motion, along with a dozen small propellers on the top of the dual body design, presumably to give it maximum range while still allowing the craft to hover.

With a weight of 5 kg and a wingspan of about a meter, Wing’s drones are capable of lifting and carrying a payload of about 1.5 kg. This puts it into a category of drones far beyond of what hobbyists tend to fly on a regular basis, and worse, it involves Beyond Visual Line Of Sight (BVLOS for short) flying, which is frowned upon by the FAA and similar regulatory bodies. What Google/Alphabet figures that can enable them to make this kind of service a commercial reality is called Unmanned aircraft system Traffic Management (UTM).

UTM is essentially complementary to the existing air traffic control systems, allowing drones to integrate into these flows of manned airplanes without endangering either. Over the past years, it’s been part of NASA’s duty to develop the systems and infrastructure that would be required to make UTM a reality. Working together with the FAA and companies such as Amazon and Alphabet, the hope is that before long it’ll be as normal to send a drone into the skies for deliveries and more as it is today to have passenger and cargo planes with human pilots take to the skies.

Pushing Tin Remotely: The Start Of Flight Control In The Cloud

September 4, 2018 by 59 Comments

In a 1999 movie (Pushing Tin), a flight controller is a passenger on a plane and tells the flight attendant that he needs to speak to the person controlling the plane. The flight attendant tells him the pilot is very busy to which the controller responds, “…you really think the pilot is controlling this plane? That would really scare me.” We wonder what that fictional character would think flying into Loveland Colorado. Their Colorado Remote Tower Project. While there’s still a human flight controller, they aren’t physically located at the airport and rely on remote cameras and radar so the controller can be located elsewhere.

The subject airport is the Northern Colorado Regional Airport and is the state’s busiest airport that has no tower. While the concept — generically known as Remote and Virtual Tower or RVT — dates back to 2002, its adoption is only now starting to pick up steam. An airport in Sweden was the first to go live for normal use in April of 2015, but the Colorado installation is the first approved in the United States. If the official site is a little too dry for you, there’s a CBS report with a video that gives you a quick overview of what’s happening. Or dive in with the demonstration video you can see below.

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Aireon Hitchhikes On Iridium To Track Airplanes

December 27, 2017 by 21 Comments

SpaceX just concluded 2017 by launching 10 Iridium NEXT satellites. A footnote on the launch was the “hosted payload” on board each of the satellites: a small box of equipment from Aireon. They will track every aircraft around the world in real-time, something that has been technically possible but nobody claimed they could do it economically until now.

Challenge one: avoid adding cost to aircraft. Instead of using expensive satcom or adding dedicated gear, Aireon listen to ADS-B equipment already installed as part of international air traffic control modernization. But since ADS-B was designed for aircraft-to-aircraft and aircraft-to-ground, Aireon had some challenges to overcome. Like the fact ADS-B antenna is commonly mounted on the belly of an aircraft blocking direct path to satellite.

Challenge two: hear ADS-B everywhere and do it for less. Today we can track aircraft when they are flying over land, but out in the middle of the ocean, there are no receivers in range except possibly other aircraft. Aireon needed a lot of low-orbit satellites to ensure you are in range no matter where you are. Piggybacking on Iridium gives them coverage at a fraction of the cost of building their own satellites.

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