PAGE Author

All posts by Urban Mäder

New Update Policy

What is it about?

One of the defining characteristics of the FLARM ecosystem from the beginning has been the obligation for regular software updates: the devices receive an “expiry date”, before which an update must be performed. If the date is exceeded without an update, an error message is displayed and the device stops working.

The original model with update cycles of 3-4 years was replaced around 2015 by a rolling scheme, where the current software always had a validity of at least 15 months: This ensures users that their devices will always function if an update is done at least once a year, e.g., in spring. This update can be easily integrated into the annual maintenance cycle, as is commonly practiced in general aviation.

Updates have been (and are) provided by us in a timely and free manner on the website, for all generations of devices. Nevertheless, there are groups of users for whom an annual update is difficult to implement:

  • In certified avionics, as used in rescue helicopters, for example, a software change usually means an expensive and elaborate project for recertification.
  • For infrastructure devices, such as FLARM receivers in wind turbines, access is sometimes limited and difficult.
  • For paragliders or drones, there is usually no natural annual maintenance cycle. For these users, the update obligation represents an additional complexity.

The world is changing rapidly: The above use cases are becoming increasingly important for the FLARM universe. For these reasons, we have decided to replace the update obligation with an alternative system.

Why are updates important?

The crux of the matter is the radio protocol with which FLARM devices communicate: FLARM devices can only fulfill their safety function if all devices speak the same “language”.

It’s about more than just sorting bits and bytes correctly: The entire process chain from sensor to radio packet to display must be consistent to produce a reliable display in the cockpit. Aspects such as filtering of sensor data, protection of privacy, compliance with international standards, etc., need to be considered. We have extensively described our position on these topics over the years (2008, 2015, 2019).

Mandatory updates are an effective method to improve and adapt the radio protocol: At each expiry date, there is the possibility to change the protocol. We have used this opportunity repeatedly since the inception of FLARM.

What changes?

In internet communication protocols, it is standard practice to agree on a common version of the protocol when establishing a connection: Usually, the highest possible version is used. For compelling reasons (such as a security issue), affected versions can be specifically deactivated.

Unfortunately, this procedure is not directly applicable to FLARM, as it does not involve a point-to-point connection: Each transmitted radio packet can, in principle, be received by dozens of devices simultaneously, all with different software versions. A connection establishment never takes place.

Therefore, we are implementing dynamic versioning: Devices choose the version of the transmitted protocol based on knowledge of other devices nearby. For example, if a current device encounters an outdated one, it situatively switches to an older protocol, depending on factors like distance or the danger of the other aircraft.

What’s next?

The transition to dynamic versioning is complex and requires meticulous planning: Dozens of device types from three generations with sometimes very limited resources must be considered. To manage this without interruptions, we had to take our time: We have been working on the conversion for more than three years already.

Hopefully, by mid-2024, the first software updates without an expiry date will be available for download for most devices!

Do I still need to update my device?

We still recommend updating FLARM devices once a year. On the one hand, this corrects any errors in the software and adds new features; on the other hand, older versions will be less prioritized by the network over time.

RemoteID for Atom UAV and Aurora

Atom UAV and Aurora, our FLARM products specifically for UAS and drones, now officially comply with the RemoteID specifications according to the ASTM F3411-19 and EN 4709-002 standards. You can download the Declaration of Conformity from the our web page: Atom UAV, Aurora.

EASA introduces ADS-L in new U-Space regulation, further defines e-Conspicuity

If you were worried about running out of stuff to do during the holiday season, EASA has you covered with some solid reading material: Just days before the deadline, they finally published the Acceptable Means of Compliance (AMC) and Guidance Material (GM) to their U-Space regulation framework. This considers countless feedbacks and comments to their initial draft from a year ago (NPA 2021-14).

Three, not one

Lost in the press coverage (interestingly, also in EASA’s own press release) is the fact that the publication consists of three decisions, not just one:

These decisions reflect the Implementing Regulations (EU) 2021/664, 665, and 666, respectively. For FLARM users, ED 2022/024/R is probably the most interesting, so let’s dive in.

SERA 6005

The Implementing Regulation (EU) 2021/666 added a single bullet point to SERA.6005, the article that governs the requirements for transponders and radios in certain airspace, such as transponder-mandatory zones. It simply adds the following bullet to SERA.6005:

(c) U-space airspace
Manned aircraft operating in airspace designated by the competent authority as a U-space airspace, and not provided with an air traffic control service by the ANSP, shall continuously make themselves electronically conspicuous to the U-space service providers. 

How specifically this is to be done was left to further regulation. Since 2021/666 would become active on January 26th, 2023, EASA needed to publish the AMC/GM well before that date – which is what happened now.


ED 2022/024/R introduces four means to be conspicuous:

  1. Certified ADS-B on 1090 MHz
  2. Certified ADS-B on 978 MHz (UAT). This is not currently practical as the frequency band is mostly unavailable for aviation use in Europe.
  3. ADS-L 4 SRD-860: This is comparable to FLARM. FLARM is mentioned in the decision.
  4. Through mobile telecommunication networks, including mobile phones or discrete devices. This is still largely undefined.

ADS-L 4 SRD860 is a “FLARM-like” standard that will likely be published early next year. We were instrumental in developing this new standard, together with other manufacturers. The standard is designed to be technically compatible with older FLARM hardware, such that they could be made to at least transmit ADS-L.

Update: The standard has been quietly published on January 25th, 2023: Technical Specification for ADS-L transmissions using SRD-860 frequency band (ADS-L 4 SRD-860).

Ok, but will ADS-L replace FLARM?

In all likelihood, no.

ADS-L is designed as a surveillance system focusing on air-to-ground transmission – it’s not very well suited for air-to-air interaction. For instance, it supports three distinct radio channels (frequencies) that a portable or installed unit cannot easily monitor concurrently. The payload is structured for tracking aircraft, lacking the accuracy needed for collision avoidance. The standard is also incomplete, as it only defines the radio protocol, not the many other aspects of an effective traffic safety solution (this is a point we made a long time ago in a whitepaper). The list goes on.

Assuming the ADS-L standard evolves in future updates geared towards air-air interaction (possible), then there is still the problem of adoption: Currently, there are no active U-Space airspaces throughout Europe. Nobody is required to use it. Even if U-Space was abundant, there are still three other means to comply with the rule, so fragmentation of the installation base has to be expected.

What can we expect from FLARM?

We have invested a lot of effort into helping develop the ADS-L standard since we believe it will be valuable as a tool for surveillance. An open standard is easier to adopt by Air Traffic Management, which would be truly amazing: In place of traditional transponders, you may soon access airspace (e.g. a TMZ) with only your FLARM turned on! Enabling ADS-L on our existing products is feasible by design. We will thus work on providing this via software updates eventually.

But for now, please excuse us while we get a good cup of coffee and start reading up on EASA’s freshly published documents…

Reminder: Aircraft tracking websites still violate your privacy rights

Whenever you fly an aircraft, chances are that you are perfectly identifiable and trackable almost everywhere. Aviation tracking websites like flightradar24 or FlightAware have made identifying, locating, and following an airplane very simple (and fun). Multiple tracking technologies are used to achieve this: ADS-B, MLAT, and FLARM. Flight data is stored in a database and can be recovered by users long after the fact.

This is an example of a private flight:

The General Data Protection Regulation (GDPR, or DS-GVO in German) became active in 2018 in the whole European Union. The law mandates companies to be more diligent in handling their customers’ personal data. Crucially, before any data can be processed or stored, the customers (“data subjects”) have to give their consent.

Back to tracking websites: Locating airliners is not usually a problem since it is hardly possible to relate a flight to a person (unless you are John Travolta). For private and hobby aircraft, however, the interpretation is quite different: Flight data are clearly personalized and should be treated as such, following the rules of the GDPR.

Of the above-mentioned systems for tracking, FLARM is the only one that offers privacy features by default:

  • Tracking can be disabled in the configuration (“No Track”). This information is then transmitted in the tracking data and generally respected by the receiver networks. Rogue receivers may still record the full data.
  • The sender address (the unique number identifying each FLARM sender) can be randomized, completely disguising the identity of the sender. The address will further be updated during the flight, making it increasingly difficult to correlate data, even for non-compliant rogue receivers.

FLARM thus both offers a way to signal consent, as well as technical means to work against non-complying receivers. ADS-B and MLAT do not offer this.

Four years after its introduction, aircraft tracking websites thus still violate the GDPR.

Further reading: GDPR (Wikipedia), AOPA on the same topic (German, 2018)

FLARM Wins fliegermagazin Award 2022

We are delighted and honoured to win the fliegermagazin Award 2022 for the best traffic detection product. Thanks to the readers of fliegermagazin for this! Our PowerFLARM Portable is a tried-and-true solution for detect and avoid and still the most comprehensive and complete portable FLARM product available on the market.

To be honest, we were surprised that Portable beat the new PowerFLARM Fusion. Still, we interpret the award as a strong statement for the need of a self-contained, fully-featured FLARM solution that is easy to use for individuals. We will continue to work hard on a world with no midair collisions.

Situational Awareness in Aerobatics

To many pilots, aerobatics is the ultimate form of aviation: It requires extensive training; the mental and physical stress is enormous, but so is the satisfaction when a figure worked out, not just ok, but perfectly precise and by the book!

Collisions with other aircraft are usually prevented by making sure there are no other aircraft around before starting with the aerobatics program. While easy enough in a competition (think aerobatics box), it is more challenging for training. For instance, a visiting pilot may not be aware of the aerobatics activity. The aerobatics pilot also has a high workload due to the demanding piloting and the physical stress. Moreover, due to the quick flight direction changes, little time remains to scan the airspace properly. Hence, proper see-and-avoid is extraordinarily demanding.

How do professional aerobatics pilots deal with this situation?

Meet Ernesto Maurer of the Fliegermuseum Altenrhein (FMA). Ernesto has logged hundreds of hours on the Pilatus P-3 and PC-7 military trainers and routinely flies aerobatics programs at air shows or with passengers. He is also responsible for maintaining and updating the avionics in these airplanes. To improve situational awareness, FMA has equipped its aircraft with PowerFLARM Fusion.

Watch Ernesto talk about it:

Even if you are not into aerobatics, consider this: The next situation where time is short and workload high might be just around the corner. If you equip your aircraft with PowerFlarm, you have one thing less to worry about: Being surprised by another aircraft on a dangerous course! Peace of mind is attainable in this case.