AltMoC, ELOS, and special conditions address different situations. Before drafting the dossier, you must determine whether the issue concerns the means of compliance with a requirement or the specifications in the aerodrome's certification basis.
Where does the categorization start?
Record the exact requirement, the edition, the reason for applicability, and the difference between the actual configuration and the reference one. Attach relevant plans, measurements, and limitations. A general statement such as “insufficient space” does not identify the object of the demonstration.
Create a file with three elements: the safety objective, the proposed solution, and the evidence that can be produced. Verify whether the issue can be resolved through direct compliance before choosing an alternative mechanism.
What characterizes an AltMoC?
According to ADR.OR.A.015, an alternative means of compliance is presented to the authority prior to implementation, including a description and demonstration of how the requirements are met. An AltMoC changes the method of demonstration; it does not eliminate the obligation to comply.
The dossier must explain which AMC is replaced, how the alternative functions, and how it will be verified. Include relevant procedural changes, required competencies, and evidence from tests, analyses, or controlled observations.
How does ELOS differ from special conditions?
ADR.AR.C.020 and ADR.AR.C.025 regulate the certification basis and special conditions. ELOS concerns the demonstration of an equivalent level of safety accepted by the authority for the targeted provision. Special conditions are established by the authority when existing specifications are inadequate or inappropriate under the foreseen circumstances.
Therefore, the same label does not apply to all deviations. The request must define the technical argument and the reason why the chosen mechanism corresponds to the aerodrome's situation.
How is the technical demonstration organized?
Link each statement to evidence: calculation, geometric analysis, simulation, testing, or operational record. Specify assumptions and uncertainties. Evaluate normal conditions, degraded operation, and foreseeable errors, including dependencies between control measures.
An assessment that assigns a lower risk score after introducing a procedure must explain the reduction mechanism and the possibility of verification. Phrasings such as “trained personnel” must be supplemented with the specific task, demonstrated competence, and application control.
What must be prepared for implementation and bidding?
The package includes the requirement–argument–evidence matrix, the description of the configuration, compensatory measures, and usage limitations. Prepare manual revisions, training, responsibilities, and monitoring. Identify events that trigger the suspension of the solution or a re-evaluation.
For bidding, provide the targeted requirement, the certification basis, the authority’s correspondence, and available technical data. Sky Meridian can prepare the justifications and supporting documentation; acceptance or approval remains with the competent authority, within the framework of the applicable mechanism.
Also consult the technical chapter in the guide
Discuss your project with the Sky Meridian team
AltMoC, ELOS and special conditions