Background: The end of halon in aviation
For decades, fire extinguishers containing halon were considered the standard in aircraft. Their high extinguishing effect on electrical and liquid-based fires and low residue formation made them particularly attractive for cockpits. However, halons have been under regulatory pressure for years due to their considerable ozone-depleting potential. International environmental agreements and European regulations have severely restricted or banned the use of these substances.
The European aviation regulator, the European Union Aviation Safety Agency, also consistently implements these environmental requirements. As a result, fire extinguishers containing halon may no longer be used in newer constellations. For general aviation, this raises the question of which alternatives are practicable and permissible.
The regulatory starting position
For non-commercially operated aircraft with a maximum take-off mass (MTOM) of less than 1200 kilograms, there is no obligation to carry a fire extinguisher. The situation is different for aeroplanes with a MTOM of over 1200 kilograms: a suitable fire extinguisher is also mandatory for non-commercial operations in accordance with NCO.IDE.A.160.
In practice, however, a massive problem arose. Aviation-approved, halon-free alternatives are only available on the market to a limited extent. Major airlines are themselves in the process of converting and are securing significant contingents. At the same time, certified fire extinguishers with approved successor substances such as Halotron 2 are cost-intensive. Even the smallest models available are often in the region of 1500 euros.
Safety risk in cramped cockpits
In addition to the economic burden, another serious aspect came to the fore: the health safety of the occupants. Many of the aviation-approved fire extinguishers are designed for significantly larger volumes than those found in typical four-seater cockpits.
While a standard fire extinguisher is often approved for cabin volumes of around 10 cubic metres or more, typical GA four-seaters only have around 2 cubic metres of interior space. A fire extinguisher is usually completely emptied within around ten seconds. After just a few seconds, the concentration of the extinguishing agent in such a small space can pose a considerable strain on the respiratory tract.
This created a conflict of objectives: a prescribed safety system could itself become a health hazard in an emergency. Especially in small cockpits without immediate ventilation, this risk is not theoretical.
Focus on alternative technologies
Parallel to the regulatory discussion, the market continued to develop. Compact aerosol fire extinguishers, such as those used in motor vehicles, sports boats or kitchen applications, offer a different technical approach. These systems work with potassium-based aerosols or comparable extinguishing agents that chemically interrupt flames without releasing large quantities of gas.
The devices often only weigh around 500 grams, are compact in size and cost less than 100 euros. A decisive advantage is the lower impact on passengers and avionics. In addition, they leave hardly any corrosive residue, which is a particularly relevant argument for sensitive avionics.
Against this background, the European IAOPA has asked the EASA to allow operators of non-commercial aircraft to select suitable, non-fixed fire extinguishers on their own responsibility.
EASA signals agreement to pragmatic solution
Following intensive discussions, a positive development is now emerging. The EASA is apparently following the argument that equipment that is not permanently installed does not necessarily require aviation-specific approval unless an explicit installation requirement applies.
According to NCO.IDE.A.100 (4), an aviation-specific approval is required in particular when equipment is permanently installed. For portable items that are not permanently attached to the aircraft, there is more leeway. This interpretation creates a viable option for many owners of aircraft over 1200 kilograms MTOM.
An official communication from EASA is expected in the coming weeks, which should create additional legal certainty.
Practical implementation for owners
In concrete terms, this means for affected aircraft owners:
It is advisable to select suitable compact fire extinguishers that can effectively fight fires but do not endanger the occupants in narrow cockpits. It is important that they are stored safely in the cabin, but not permanently installed - for example in side pockets or suitable compartments. Under no circumstances should the devices be allowed to move freely unsecured during flight operations.
It is also worth considering the fire risk of modern lithium-ion batteries. Statistically, portable electronic devices such as tablets or smartphones are among the most likely sources of fire in the cockpit. Fireproof bags or so-called lithium battery safety bags can be a useful addition here.
Restrictions for commercial operators
Not all operators benefit from this pragmatic solution. Certified fire extinguishers remain mandatory for commercial transport under Part NCC and comparable types of commercial use. Stricter requirements apply here, which do not allow comparable flexibility.
There is also a need for discussion in the case of aircraft whose type certificate according to CS-23 explicitly provides for a permanently installed fire extinguisher. In these cases, an aviation-specific licence could still be required. However, it is argued that other portable safety equipment such as emergency hatchets or first aid kits do not require separate aviation-specific approval either. It remains to be seen whether this logic will be fully applied to fire extinguishers in the future.
Conclusion: More sense of proportion in regulation
Current developments show that constructive dialogue between associations and regulators can lead to appropriate solutions. The combination of environmental requirements, technical safety and economic resilience regularly poses challenges for general aviation in particular.
With the pragmatic approach now envisaged, EASA is creating a balanced framework: Environmental and safety objectives are preserved, while at the same time the real operating conditions of small aircraft are taken into account. For many owners, this should mean noticeable relief - without having to compromise on safety.
Source references:
AOPA
