PAGE Author

All posts by Urban Mäder

A word on maintenance

On November 7th, a mid-air collision occurred over Mount Diablo, California, between an ASW-20 and an ASW-27 glider. Both gliders had a PowerFLARM installed, but one was not functioning due to an expired firmware. Luckily, both pilots survived by bailing out.

But why does the firmware expire in the first place?

This is our current approach to managing change in the highly distributed system that is FLARM. Unlike with other IT systems you may know, we cannot gradually update the population of FLARM devices since they all need to talk the same language (the radio protocol) to work. Firmware expiration allows us to change and improve the radio protocol safely, without rendering part of the devices dysfunctional.

Ok, so when does the firmware expire?

This is stated in the Release Notes. The published, most current firmware always has an expiration date of at least 14 months in the future. Hence, simply updating once a year as part of the annual maintenance will be just fine.

We know that maintenance is a tedious chore, especially since we only do it once per year. Remembering and doing the necessary steps each year requires a deliberate mental effort.

To facilitate the process, we have recently released the Instruction for Continued Airworthiness (ICA) document. The ICA is a beefy document that contains a lot of useful information, but the core of it is really small: The annual maintenance checklist, found in Appendix B. It contains the following points:

  1. Verify proper installation and secure mounting of installed parts.
  2. Verify that all antennas are correctly installed/placed and are not damaged.
  3. Verify that antenna cables, wiring, and connectors are  undamaged, unbent, have no corrosion or signs of water, and are correctly installed.
  4. Check if the range has deteriorated by performing a Range Analysis.
  5. Reset the Continuous Analyzer of Radio Performance (CARP)
  6. Update the FLARM firmware
  7. Update the display firmware, if applicable
  8. Check the release notes for changes. Do you need to update the configuration?
  9. Update the obstacle database if installed
  10. Check for errors during the startup sequence.

That’s it, really! Going through these 10 points once a year should be sufficient to keep your FLARM in working condition.

Read all about the accident mentioned above, including a thorough analysis by Ramy Yanetz, in the November PASCO newsletter.

First PowerFLARM Fusion delivered

Today, Patrik Eichenberger and his Flight School based in Buttwil, Switzerland, took delivery of the very first PowerFLARM Fusion with the special serial number 1. It will replace an existing PowerFLARM Core in one of their Cessna 152 trainer airplanes, where it will deliver collision warnings and traffic information on both a dedicated FLARM display and an iPad running the Air Navigation Pro app.

“PowerFLARM Fusion is a clever upgrade of our collision avoidance instrumentation, allowing us to connect the iPad directly. This makes our installation simpler and less error-prone. Honestly, configuration and maintenance of the old PowerFLARM Core was always a challenge since the device is not easily accessible”, said Patrik Eichenberger — while casually updating his first Fusion to the latest firmware on his phone.

Introducing PowerFLARM Fusion — Back to Simple!

Over the years, many features and details have been added to PowerFLARM, making it harder to understand what is going on: Is the configuration correct? What firmware version is installed, and does it need updating? Was the log file written to the flash drive? What does a solid amber light mean again? Oh my.

PowerFLARM Fusion brings simplicity back to FLARM.

An integrated Wi-Fi module hosts the FLARM Hub web application, making configuration and troubleshooting painless. FLARM Hub is a user interface for mortal humans: It runs on any computer or mobile device, offering a clean, modern, and intuitive user interface. Traffic data can be streamed to navigation apps and EFBs over Wi-Fi or Bluetooth. The range analyzer is built-in — no need to juggle IGC files anymore.

Of course, Fusion integrates the latest PowerFLARM technology, operating worldwide with optimal performance in every region. It comes fully loaded with all the features, no need to deal with options or license files. Upgrading an existing PowerFLARM Core installation is straightforward, as the dimensions are identical.

Also, it is orange.

Please read up on all the details about PowerFLARM Fusion on our product page.




Foca’s Detect-and-Avoid Dilemma

NZZ today published an article citing a recently released report by the Swiss Accident Investigation Board (Sust) on a near-miss between an A319 and a drone. The vertical distance was 10 m – scary stuff! While this was (likely) an intentional action by an irresponsible individual, we will certainly see more of this soon due to the increasing use of drones for useful purposes.

So how do we prevent such disasters from happening?

A Foca spokesperson was further interviewed in the article. TCAS and transponders are quickly ruled out as being too bulky, too power-hungry, and too expensive. Also, TCAS is a safety-critical system that safes lots of lives, today. Can we really risk to introduce many more transmitters to the same frequency band, thereby potentially reducing the effectiveness of TCAS?

The upcoming traffic management system for drones (called U-Space in Europe) will solve the problem eventually, but there is still a very long way to go: The federated, distributed approach that is currently adopted uses the internet as communication backbone. Robust network access is thus required for all participants of U-Space, which is no small feat for an airliner moving through the air at 150 knots. Federation also means that the overall complexity will be much higher compared to a centralized system to achieve the necessary standards for reliability, availability, and safety.

So what else? FLARM is mentioned as a promising technology, but lacking an open standard. But such a standard exists and can be downloaded here. Unlike other standards for Remote ID, our proposal does not use the 2.4 GHz frequency band that is so densely used and limited in achievable range. Based on our standard, Detect & Avoid and Remote Identification applications can be built that provide the performance needed to protect the crews and passengers in airliners. No need to wait for the future.

Kollionsgefahr: Passagierflugzeuge sollen vor Drohnen gewarnt werden
Summarischer Bericht
FLARM UAV eID Standard

Swiss Army procures Lockheed Martin’s Indago 3 drone with FLARM for SAA

The Swiss Army just announced the procurement of Lockheed Martin’s Indago 3 reconnaissance drones. These vehicles carry a miniaturized FLARM as part of their sense-and-avoid suite. Nearby manned traffic will be displayed to the drone operator so conflicts can be easily avoided. Likewise, the drones will be visible to manned traffic as well.

This is another strong argument for technical diversity in electronic conspicuity: No single technology is capable of covering all the use cases. The integration of a FLARM system is simple and inexpensive. There is no need for an expensive and unreliable infrastructure for rebroadcasting signals – it just works.

Press release: Swiss Army Chooses Lockheed Martin’s Indago 3 UAS for Tactical Reconnaissance and Surveillance

Media coverage: AGEFI 2020/09/11

Droniq UTM enables BVLOS flights drones, uses FLARM for deconflicting

Droniq recently announced the release of its next-generation UTM specifically for long-range flights with no visual line of sight to a human operator (BVLOS).

Enabling BVLOS flights while maintaining a high level of safety is considered critical for unlocking the full business potential of the drone industry, as it allows unprecedented automation and scalability.

Key to the Droniq solution is the Hook-on-device (HOD) transponder. The HOD contains an LTE modem for telemetry, video, tracking, command-and-control, and traffic deconflicting. It also integrates a full and independent FLARM transceiver, detecting (and being detected by) a large number of FLARM-equipped aircraft, both manned or unmanned. This safety function is independent of cellular coverage, providing protection when the LTE link does not.

The addition of BVLOS capabilities makes the Droniq solution the most complete and most usable German UTM solution available today, adding value to all aspects of drone operations.




OGN network wins EASA GA Safety Award

OGN network was started by Pawel Jalocha in 2012 with the idea of creating an inexpensive ground receiver for FLARM signals, network them and to stream live traffic because doable, fun and useful. The technical approach was brilliant: Instead of creating expensive custom hardware, he took advantage of an inexpensive tunable USB TV receiver (also known as software-defined radio), plugged it into a small Linux computer (also known as Rasberry-Pi and comparable designs), and applied a bit software wizardry to process FLARM signals instead of an episode of “Simpsons”.

Every OGN station receives signals from FLARM and later also other conspicuity (or how EASA has recently started to name them: iconspicuity) devices. The traffic data is streamed via the Internet to a cloud server, then distributed to a growing number of applications, both on the ground and in the air. These include visualization, flight tracking, flight time logging, search-and-rescue, archiving, accident investigation assistance, airspace design assistance, re-broadcasting for non-interoperable other conspicuity devices and more. Thus the purpose has clearly gone into the safety domain.

OGN quickly grew thanks to its active community, offering attractive additional services for aviation, the basic ones mostly for free, some at cost (especially when related to hardware), some in a commercial context. Today, its nearly 2’000 receivers cover large parts of Europe and many smaller areas in the rest of the world. The majority of data processes and airspace users tracked with OGN even today is FLARM, used by more than 50% of all aircraft and an exploding number of other users in Europe and the rest of the world.

Today, we are pleased to learn that OGN and its current main coordinator, Sebastien Chaumontet, were awarded the EASA GA Safety Award. We fully support this decision and congratulate Seb, Pawel, Philippe Boissel, Wojtek Buczak, Melissa Jenkins Andersson, Gerhard Wesp, Angel Casado (the most active contributors in the past and present) and the whole community of broadcasting airspace users and receiver operators on this achievement.

We did not initially buy into the idea of OGN when Pawel first expressed his early ideas when working for us in 2011, and we voiced strong concerns on several legal and IP aspects around OGN in 2014/2015. In parallel, we also actively contacted the team behind OGN starting in 2014 and offered assistance. Starting in 2015, we improved the radio communication in order to make OGN better, added several features to accommodate the extended needs from pilots being exposed to public tracking via OGN, and ensured OGN’s decoding staying interoperable through all major updates released so far.

Looking forward we wonder: If EASA endorses non-certified, direct-broadcast and non-networked electronic conspicuity technology in manned aviation – why is the same not possible for UAV? Why do we instead mandate complex, distributed, expensive, and fragile systems that can only ever be built multi-billion-dollar companies?


Introducing Continuous Range Analyzer

How do you know if the radio range of your FLARM installation is sufficient?

As you should know, verifying the radio range is crucial for any FLARM installation: cables, connectors, and antennas may slowly deteriorate due to oxidation, mechanical stress, or simply aging. Hence, the radio range should be checked regularly by using the online Range Analyzer tool.

The Range Analyzer works with one or more FLARM flight logs (IGC files). It uses data from received traffic for a statistical analysis, which is then presented graphically. For meaningful results, it requires a large number of contacts during flight – a record from a nice summer day is better than one from a night flight in the winter.

Storing all proximate traffic in the memory of the device is not possible. Until now, a majority of the data had to be discarded and could not be used by the range analyzer. The just-released CARP, or Continuous Analyzer of Radio Performance, solves this with a clever trick: The range statistics operations are performed on-the-fly, while the data is being received. The statistical range is continuously integrated over time with each aircraft that comes within, or disappears out of, range. Thanks to CARP, less flight time will be needed to get a range measurement and the measurement will be more reliable.

An example of the new CARP Range Analyzer results is shown below.

With FLARM firmware version 6.80 and later, CARP range data is automatically written to IGC files being recorded on the FLARM device after each flight. Each IGC file will thus contain both the new CARP data and the classic non-integrated, but quantitatively limited, data; the latter being used for e.g. SAR purposes.

Since CARP integrates the data over time without any restriction, it has to be reset manually when needed. If the data collection period is too long, a recent degradation in the installation quality might not be visible. It’s advisable to reset CARP at least once per year, e.g. during annual maintenance, after the old CARP data (latest IGC file) has been read out and retained. CARP is normally reset using the connected FLARM Compatible display. For displays that don’t have this capability, CARP can also be reset using the Configuration Tool. To avoid reconfiguring the device, a config file that only resets CARP can also be downloaded here.

CARP is available in all PowerFLARM-based devices which have firmware version 6.80 or above.

Computer Vision to Assist Pilots

See-and-avoid is still the gold standard for collision avoidance in aviation, especially in VFR. There is simply no system that can detect all traffic, from airliners to single-engine piston aircraft, paragliders, and UAVs. Looking out is still part of the routine of even airliner pilots – especially while flying through Class E airspace shared with General Aviation (as is shockingly common, for instance, in Germany and Switzerland).

Alas, human vision is notoriously limited and pilots have more than just this one job to focus on. So why not help the humans (and similarly, air traffic control on the ground) by pointing out traffic they may have missed, complementing cooperative systems like transponders/TCAS, ADS-B, and FLARM?

Together with the Computer Vision Laboratory (CVLAB) of the EPFL in Lausanne, we have developed a leading-edge architecture together with a set of algorithms to do exactly that. It detects and classifies other manned aircraft and some other hazards in a live video stream from one onboard camera based on hardware that can fit into a GA cockpit. This information can then be used to track and locate targets, to issue warnings to the pilots and even to automatically recommend and execute avoidance maneuvers. Some algorithms are based on the well-researched YOLO architecture, using tools from deep learning and convolutional neural networks (CNN) to achieve high accuracy while running in real-time. Other algorithms apply common computer vision algorithms.

A crucial part of deep learning methods is to have a large set of sample data that can be fed to the algorithm for training. The data first needs to be annotated by humans, which can be a very tedious task. CVLAB has developed tools to make this efficient and together we have annotated a huge set of video data from many flights conducted under various traffic and environmental conditions.

The first video below is made by EPFL to explain the project, the challenges that they faced and how they were solved. The second video shows a clip from the onboard camera with aircraft identification annotations made by the deep learning algorithms.