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Wind turbines: New regulation on the marking of air traffic obstacles

On 11 February 2021, the Regulation of the Minister of Infrastructure of 12 January 2021 on Air Traffic Obstacles, Obstacle Limitation Surfaces and Dangerous Devices came into force. In the method of notification and marking of air traffic obstacles, it replaced the regulation of 25 June 2003. Will wind turbines still need to be marked under the new regulation? If so, who should mark them and how? And, just as importantly, does existing marking need to be brought into compliance with the current regulations, and if so, when?

Onshore and offshore wind turbines as air traffic obstacles

In Poland, there is a new wave of investment in wind turbines, both onshore, due to recent auctions, and offshore, whose capacity in the first stage will amount to 5,900 MW. Higher and higher structures, exceeding 300 m, are being erected, raising to new relevance both the Aviation Law of 3 July 2002 and the new regulation, insofar as they relate to the marking of air traffic obstacles.

Under the current definition, introduced in 2019 (Aviation Law Art. 871(1)), air traffic obstacles are objects:

  1. Higher than the heights determined by the designated obstacle limitation surfaces (defined in accordance with §§3–20 of the regulation, setting boundaries within which natural and artificial objects, including structures, should not be higher than the heights defined by these surfaces)
  2. More than 100 m above the surrounding ground or water level, in the territory of Poland or the Polish exclusive economic zone
  3. On a runway, regardless of height
  4. Other than those indicated above, if they have been recognised as an obstacle in a decision by the president of the Civil Aviation Authority, the Minister of National Defence, or the Minister of Interior and Administration, because they pose a potential hazard to aircraft movement.

Therefore, there is no doubt that this definition concerns all kinds of objects (both natural and artificial) which, due to their characteristics (height) or location, constitute a threat to the safety of aircraft movement. Without a doubt, wind turbines (especially onshore) may also constitute obstacles of this kind, due to their height, which in some cases is several hundred metres above ground level. Meanwhile, the minimum altitude for visual flight (visual flight rules) in Poland is 150 m.

A whiter shade of pale

The rule under Art. 872(1) of the Aviation Law is that all objects constituting air traffic obstacles should be marked in accordance with the regulation (unless these provisions exclude their marking or the competent authority has exempted them from marking).

The marking should ensure the visibility of the air traffic obstacle during day and night from any direction and indicate its location, general shape and size. The new regulation maintains the division of air traffic obstacle markings into daytime markings (painting, marker balls on power lines, and with the consent of the authority, flags, boards or obstruction lights) and night-time markings (obstruction lights).

Pursuant to §27 of the regulation, a wind turbine that is an air traffic obstacle should be marked by painting it white, with the rotor blades, nacelle and upper 2/3 of the support structure painted. This is consistent with par. of the ICAO recommendations, Annex 14 “Aerodromes,” vol. I, to the Chicago Convention on International Civil Aviation (“The rotor blades, nacelle and upper 2/3 of the supporting tower of wind turbines should be painted white, unless otherwise indicated by an aeronautical study.”) Thus, the new regulation drops the obligation to paint the ends of rotor blades with red/white or orange/white stripes (§21 of the regulation of 25 June 2003 stated that wind turbines that are air traffic obstacles should have their external ends painted with five stripes of equal width, perpendicular to the longer dimension of the propeller rotor blade, covering 1/3 of the length of the propeller rotor blade (three in red or orange and two in white); the end stripes must not be painted white).

The new regulation seems to exclude the possibility of painting wind turbines in colours other than white (e.g. light grey or beige). However, “to interpret the requirements of the regulation uniformly,” the president of the Civil Aviation Authority decided to regard as “white” not only RAL values referring to different shades of white (1013, 9001, 9002, 9003, 9010, 9016), but also some defining shades of grey (9018, 7047, 7035, 7038 or 7047). Therefore, it seems that colours indicated by the regulator may be considered derivatives of white, thus complying with both the Polish regulation and the ICAO recommendations.

Undoubtedly, the extension of the colour range will reduce costs of production and maintenance of wind turbines, but it is too bad that such details were not included directly in the regulation.

New rules for very tall wind turbines, mainly offshore

In turn, the night-time marking of a wind turbine (pursuant to §37 of the regulation) should use a medium-intensity obstruction light on the highest point of the nacelle (and, in case of a turbine with a height of at least 150 m, additionally a reserve obstruction light). At the same time, which is new compared to the 2003 regulation, if the height of the power turbine is at least 150 m above the level of the surrounding ground or water (and if it is not surrounded by other turbines on at least four sides and within 900 m), three additional low-intensity lights are to be placed on one level, halfway between the light on the nacelle and the surrounding ground or water. The obstruction lights of wind turbines placed next to each other should flash simultaneously. For colour, signal, highest intensity values, and beam spread, §23 of the regulation refers to the appropriate tables set forth in Annex 14 to the Chicago Convention, vol. I.

Who is to mark and maintain markings of wind turbines that are an air traffic obstacle?

According to Art. 872 (2) of the Aviation Law, the following are invariably required to mark a wind turbine that is an air traffic obstacle:

  • In case of offshore wind turbines, the entity that obtained the permit to erect or exploit artificial islands, structures and equipment in Polish maritime areas
  • The owner of the real estate, perpetual usufructuary, or holder of limited in rem rights to the real estate who is the actual controller of the real estate
  • The operator of an aerodrome within whose limits the air traffic obstacle is located, if:
    • There is no owner of the real estate, perpetual usufructuary, or person who has limited proprietary rights to the real estate, or
    • If an object not previously an obstacle becomes one as a result of construction, extension or modification of aerodrome features
  • In the case of objects recognised as air traffic obstacles on the basis of a decision of the president of the Civil Aviation Authority, the Minister of National Defence or the Minister of Interior and Administration due to potential risk to aircraft movement, the applicant or, in cases initiated by the authority, the owner of the real property on which the air traffic obstacle is located.

The same entities are also obliged to maintain the air traffic obstacle marking in an appropriate condition. The marking of air traffic obstacles is supervised by the president of the Civil Aviation Authority, who, within his powers, may carry out an inspection of the marking.

When does the new marking enter into force, and how long do existing facilities have to comply?

The new regulation entered into force the day after publication, i.e. on 11 February 2021. However, this does not mean that the existing marking for all air traffic obstacles had to be changed on that date. As indicated in §61(1) of the regulation, entities obliged to mark air traffic obstacles in accordance with the previous regulation are obliged to adjust them to current requirements during the next renovation of daytime or night-time markings, respectively.

According to the explanatory memorandum to the draft regulation, this solution was introduced because new air traffic obstacle markings differ only marginally from the existing ones. The high costs associated with marking an air traffic obstacle were also taken into account. This allows obliged entities to plan the work on modernisation of the air traffic obstacle markings and link that work with any other work on the wind turbine.

However, there are no provisions specifying what the “renovation of markings” should consist of or imposing an obligation on the aforementioned entities to carry it out. Therefore, it should be assumed that the adjustment of the marking of existing wind turbines to the applicable regulations and the deadline for such adjustment will de facto depend on the investor itself or the manufacturer of the wind turbine (or possibly the producer or contractor of the marking). However, it cannot be ruled out that some wind turbines will remain marked in the current manner until the end of their operation.

As a side note, the regulation does not expressly answer the question of whether, if on the date of entry into force of the regulation, the paint coating or obstruction lights used on the wind turbine were already in the process of being “renovated,” the obligation to adjust the markings arose in connection with that renovation or will not arise until the next renovation.

At the same time, under the new regulation, all decisions of the president of the Civil Aviation Authority on determination of the type of marking of an air traffic obstacle or waiving its permanent or temporary marking, issued on the basis of §9 of the 2003 regulation, remain valid (§61(2)). Thus, as of 11 February 2021, it is not necessary to reapply for an exemption from the obligation to mark existing air traffic obstacles or permission to change the method or type of marking, under the conditions set out in §§40–42 of the new regulation.

However, additional clarification is required for the interpretation by the president of the Civil Aviation Authority stating that “potential non-compliance of the marking concerns wind turbines not yet installed, but manufactured and prepared for installation before the date of entry into force of the regulation, which for justified reasons cannot be marked in a manner compliant with the requirements of the regulation by the time of installation; §§ 40 and 41 of the regulation will apply.”

Exemption or permission to change markings: not likely for wind turbines

The aforementioned §§40–42 of the regulation govern issues related to obtaining by entities obliged to mark air traffic obstacles of:

  • Exemptions from the obligation to mark them
  • Permission to change the method (use of obstruction lights instead of painting, use of a different type of obstruction lights, use of boards and flags) or the type of marking (daytime/night-time).

Such exemption or permission is granted via an administrative decision by the president of the Civil Aviation Authority (in certain cases by the Minister of National Defence or the Minister of Interior and Administration) upon written request of the obliged entity, setting forth the information necessary to conduct an analysis of the location and shape of the air traffic obstacle, its surroundings, and the potential impact on air navigation safety.

The exemption from the obligation to mark air traffic obstacles with a height of 100 m or more above the surrounding ground or water level may be granted only after it has been agreed with the Minister of National Defence and the Minister of Interior and Administration. Moreover, in the case of an obstacle located within the obstacle limitation area, exemption or permission may be granted after obtaining an opinion from the air traffic services provider (the Polish Air Navigation Services Agency), if it operates at the aerodrome, and of the aerodrome or landing strip operator.

Additionally, the regulation lays down the conditions for obtaining the aforementioned exemptions and permissions. They may be granted only in cases enumerated in §41 of the regulation, i.e., among other things:

  • When appropriate markings cannot be used for technical reasons on an air traffic obstacle or when such markings prevent the proper functioning of an object that is an air traffic object
  • When at least three air traffic obstacles that are not wind turbines are located:
    • Within the limits of the obstacle limitation surfaces, at a distance of no more than 100 m between successive air traffic obstacles
    • Beyond the limits of the obstacle limitation surfaces, at a distance of not more than 900 m between consecutive air traffic obstacles
  • When the air traffic obstacle is of a shape indicating the need for more than one means of marking
  • When the height or shape of the marked air traffic obstacle is being changed.

Thus, the regulation has significantly limited (and in the case of a group of obstacles, outright excluded) the possibility of obtaining exemptions from the marking obligation or permission to change the method or type of marking for wind turbines. It seems that such a justifiable reason, indicated by the president of the Civil Aviation Authority in his interpretation of 28 April 2021, could only occur if, for structural (technical) reasons, it is not possible to use emergency obstacle lighting on the nacelle or additional lighting at the halfway point of the height of the tower of a wind turbine already manufactured but not yet installed. On the other hand, it is difficult to imagine a situation where the authority would allow a deviation for its daytime marking (the colour of the paint coating).

Igor Hanas, adwokat, Energy practice, Wardyński & Partners

Marcin Sobkowicz, adwokat, Aviation practice, Wardyński & Partners