There are altogether three important “flexibility tools” in the process of the certification of aerodrome infrastructure and design. Firstly, the establishment of an individual aerodrome Certification Basis (CB) includes the possible element of special conditions (SC), as described under ADR.AR.C.025 in annex II of Regulation (EC) No 139/2014. It gives the flexibility to the authority to allow deviations from the Agency’s Certification Specifications when the aerodrome is subject to topographical, physical or other limitations.
Secondly, the concept of the equivalent level of safety (ELOS), as described ADR.AR.C.020 (b) in Annex II of Regulation (EC) No 139/2014, may also allow for technological solutions or alternatives to be introduced into the CB instead of complying with the applicable certification specification(s). This is on condition that the authority allows for such an equivalent level of safety to be demonstrated (see also the Agency’s Guidance Material for ADR.AR.C.020).
Furthermore, the concept introduced by Art. 7 “Deviations from certification specifications” of Regulation (EC) No 139/2014 allow competent authorities to accept “legacy” deviations from the certification specifications until the end of 2024 for newly certified. Such “legacy” deviations have to pre-date the coming into force of the said Regulation (i.e. have existed before 6 March 2014) to continue as long as they cannot be captured with the aforementioned concepts, are safety assessed, mitigated and undergo regular reviews to establish their continued legitimacy. Such acceptances may be formalised in what is called a “Deviation Acceptance and Action Document” (DAAD).