1.Each operator or aircraft operator shall monitor greenhouse gas emissions, and non-CO₂ aviation effects, on the basis of a monitoring plan approved by the competent authority in accordance with Article 12 of this Regulation, taking into account the nature and functioning of the installation or aviation activity to which it applies.

The monitoring plan shall be supplemented by written procedures which the operator or aircraft operator establishes, documents, implements and maintains for activities under the monitoring plan, as appropriate.

2. The monitoring plan referred to in paragraph 1 shall describe the instructions to the operator or aircraft operator in a logical and simple manner, avoiding duplication of effort and taking into account existing systems in place at the installation or used by the operator or aircraft operator.