What is ADS-B?

ADS-B is probably familiar to all of us by now. It stands for Automatic Dependent Surveillance-Broadcast. An ADS-B system provides two different services, ADS-B OUT (Send) and ADS-B IN (Receive).

In addition to providing ADS-B In and Out compliance, a modern Mode S transponder will also display GPS position and pressure altitude, as well as weather and traffic. Furthermore, an internal attitude sensor allows for viewing dynamic pitch and bank information on an external GPS or tablet.

When fully implemented, the system will provide even more functions and enhanced services. I will, however, focus on the aspect of aerial firefighting that interests me most: self-separation between low-level non-coordinated aircraft.

Why do we need self-separation?

In the two photographs below, how many aircraft do you see through the smoke in the first one? Three? Four? Well, there are a few more!

The second photograph shows the Athens area during the terrible fires of 2021. Only a small portion of the fires in the locality are pictured as they burned over a wider region of 125,000 hectares.

In a two nautical-mile radius, at least six aircraft can be seen. Some are en route to load water; others are coming from the water source; some are approaching from nearby airfields, and the one on the far right is dropping. Smoke in the area and the mountainous terrain may have masked low-altitude traffic, so there could be even more.

In an ideal world, the coordination of this scenario would operate like an orchestra, where each instrument would participate according to the conductor's command, and those involved in the process would follow a standard procedure that is known to all. Unfortunately, due to the conditions I will describe below, the reality is more like a jungle – everyone works separately or in smaller groups, developing their own ways to mitigate existing threats.

The dangers of the jungle

Even though I have used Greece as an example, this can happen in any country that is hit by multiple large fires requiring more assistance than it can provide alone. Usually, this is found in Mediterranean countries and Portugal, but more recently we have also seen it in Sweden and other nations less prone to wildfires.

International cooperation is an essential symbol of solidarity and globalization that can help us prevail in tough times. Still, combining local and foreign assets creates inevitable disadvantages on which we must continue to work.

In Greece, there were aircraft operated by the Hellenic Air Force (Canadair CL-215/CL415T, PZL-Mielec M-18) as well as the fleets of civil operators providing Sikorsky S-64 Erickson Air Crane heavy helicopters or amphibious scoopers like the Air Tractors Fire Boss, brought from as far away as Australia. In addition, other aircraft were provided through last-minute direct contracts, as well as by NATO, and the European Commission through RescEU.

The result is an impressive variety of aircraft with different capabilities and performances that any museum would be proud of – from a light SEAT to a Beriev Be-200, Canadairs, all sort of impressive helicopters and anything in between.

Operational downsides include cultural and linguistic barriers, as well as non-standard equipment. While VHF coordination in English is theoretically essential for safe and effective operation, currently this is not always possible when there are too many different fires, not enough coordination aircraft, or a combination of both. In these situations, it is necessary to stick close to a local aircraft that’s able to communicate with ground forces, or add this capability to the foreign asset, typically by an FM radio and a local translator, who might be neither a pilot nor a translator.

The photographs illustrate that separation loss below reasonable minima caused by the factors just mentioned is a concern in our low-level busy space.

If a picture speaks a thousand words, a video must speak a million. These two screen-grabs (below) show an ‘oh almost’ that could have quickly turned into an ‘ouch’. (Photo courtesy of Javier Ramos, Spanish 43 Group)

When we are used to working in scenarios where emergency operations become the norm, we cannot pretend that in an overwhelmed country that needs international assistance, the operation will run like a Swiss clock, or that aircraft coordination will be as effective as at an airport. If those were our expectations, we probably ought to change careers.

In some cases, what we can (and probably should) do is suggest or insist on tools and technologies that will increase our safety while ensuring our contribution's effectiveness. Regulatory documents are approved in offices, but remember that inputs providing guidance for procedures should emanate from the operational front line!

Mitigating threats

Or how to potentially reduce the likelihood of unintentional crossings between traffic and loss of separation.

I find the two photographs to be very illustrative, since they summarize so much of what I’ve described in this article. In the upper image you can see the actual scenario, while in the lower picture, you can see the synthetic one. By using a US$3,000 ADS-B In/Out transponder, we can create an artificial situation that combines an attitude and heading reference system (AHRS, which also serves as a backup instrument) with GPS information, terrain, obstacles, and traffic. Note the antenna on the right and traffic advisory, providing both visual and acoustic warnings.

Information like this is extremely useful when there is not enough information to assemble a mental map of the situation. By providing a single display, we are increasing the pilot's situational awareness so he doesn't have to rely exclusively on data provided by the coordination aircraft (which, as we said, is not always present), nor on his primary senses; vision to look for other traffic when visibility is reduced, or hearing to listen to frequencies that are sometimes saturated or full of unnecessary noise. In Europe, it is well known that English Level 4 doesn't guarantee fluid or effective communications!

An ADS-B synthetic view also mitigates other hazards associated with mountainous terrain that should be in every firefighter's hazard log, more specifically illusions due to false horizon perception or mountain relative scale.

The road to full implementation

Among the different aeronautical agencies, the roadmap for complete implementation appears to be quite similar, even though it is easy to get lost in the nuances of dates, extensions, and exemptions of the leading authorities that meet in major international fires (EASA, FAA, TSB of Canada, CASA).

In my experience, as someone who has already benefited from the use of ADS-B in an N-reg aircraft in Chile during early 2019, as well as in the last international deployment to Greece, I was surprised to learn that in 2021, only American and Australian aircraft, along with the Swedish AT-802 Fire Boss, were already in compliance with the mandate in a major European international operation.

While the benefits are clear and the cost of an upgrade is not exorbitant, operators may only implement the system if it is required and not just optional. As it stands, several exemptions could result in a significant portion of the aerial firefighting fleet not being ADS-B compliant, as shown below and seen recently in Greece:

‘The ADS-B mandate is only applicable to IFR/GAT operations with at least 5.7 tons MTOW or 250 KTAS (knots true air speed) max cruising speed.’ Therefore, light helicopters are excluded from this coverage, yet firefighting scenarios are full of them.

‘Old aircraft (CoA before 7 June 1995), aircraft that operate maintenance or export flights, and aircraft that cease operations in airspace by 31 October 2025 are exempt.’ It is expected that the old firefighting aircraft will remain out of scope for at least the next few years, and that firefighting scenarios will still continue to use repurposed aircraft from the 1960s and 1970s, as has been the case throughout history.

‘There are certain circumstances in which state aircraft are exempted.’

A large number of aircraft in the firefighting scene could be considered state aircraft in the context of public-private partnerships, where military and civil aircraft are usually working together for the same cause.

In addition, from a broader regulatory perspective, according to the EASA regulations, firefighting is specifically excluded as per Article 2(3) of the Basic Regulation (EU) 2018/1139. This means that for many aircraft, following what is stated regarding equipment (SPO.IDE) or its annexes will not be required, leaving each specific member state to decide how to approach activities.

‘This regulation shall not apply to:

(a) aircraft, and their engines, propellers, parts, non-installed equipment, and equipment to control aircraft remotely, while carrying out military, customs, police, search and rescue, firefighting, border control, coastguard or similar activities or services under the control and responsibility of a member state, undertaken in the public interest by or on behalf of a body vested with the powers of a public authority, and the personnel and organizations involved in the activities and services performed by those aircraft.’

Cooperation enhances safety

International cooperation in aerial firefighting is a reality that we see every season.

Throughout the past decade, a number of efforts and projects have been undertaken to create a standard of regulation for all EU members and a single EU sky. However, for aerial firefighting and other public interest activities, its regulation has been delegated to individual member states, making it impossible to standardize, resulting in some dangerous scenarios during international collaborations.

If the use of ADS-B is considered necessary for the safety and efficiency of airspace management aimed at aircraft submitting flight plans, controlled and separated from each other by radar, flying IFR on predefined airways, I strongly believe it should be even more necessary for aircraft performing aerial firefighting missions regardless of the speed or weight of the aircraft, its year of manufacture or its civil or military status. All of them operate without a flight plan or radar control, under precarious or non-existent coordination conditions through the free circulation layer (uncontrolled airspace), often with reduced visibility.

More specifically, I find it odd that on the one hand, two modern and well equipped Daher TBM 900s flying IFR on airways miles apart, carrying three or four onboard at FL300 and 30kts, are required to be ADS-B compliant. On the other hand, a Bell 412 flying in a jungle of traffic and carrying 13 souls is not, as it does not exceed 5,700kg or 250kts. The same goes for a state-operated CL215, C-130 or similar military aircraft, and any other aerial firefighting aircraft that is not included in the basic regulation because it is not deemed mandatory by its governing agency.

Perfect is the enemy of good

In the form of mandatory requirements, the following four imperfect but real mitigation measures could help us avoid the incidents and accidents described in this article:

ADS-B for all aircraft involved in firefighting, without exception.

For crews participating in international missions, English proficiency should be at least Level 5, preferably Level 6.

Continuous and professional aerial coordination over the fires. We are focusing on sending firefighting aircraft, but less on coordination aircraft, which are essential to the effectiveness and safety of the firefighting aircraft below. In most scenarios, we lack a fleet of well-equipped long endurance aircraft, such as a simple Cessna 208 or similar, loaded with a team of professionals who are able to coordinate the firefighting aircraft, while understanding fire behaviour.

The implementation of a brief, but mandatory European standard procedure for aerial firefighting, made by professionals for professionals. At the moment, no such standard exists.

These are only four small improvements out of many that would significantly enhance safety, while we still wait for the definitive plan of a single European sky, a robust common aerial firefighting standard operating procedure (SOP), a modern standardized dream fleet, and so on. All of that may come at some point, but what is for sure, is that next season aerial firefighters will all have to meet up again somewhere.

We should be ambitious about tackling large problems, but the key remains to focus on the small details – ‘Le mieux est l’ennemi du bien’, which means ‘Perfect is the enemy of good’. Voltaire's view is based on what is known today as the Nirvana fallacy, which involves rejecting an action or idea by comparing it to the most ideal, with that ‘best intended outcome’ that it is so good that it ends up being incomprehensible or impossible.

Every small thing is like a building block: regardless of how big or ambitious the end goal is, whether it is achieved or not is determined by the quantity and quality of its smaller components.

Since we are not responsible for regulating operations, we may not have the opportunity to do great things, but nothing stops us from doing small things in a great way, by being proactive and suggesting solutions.

Bring them on!