Navigate / EASA

GM1 ATM/ANS.OR.A.045(c); (d) Changes to a functional system

ED Decision 2017/001/R

TRANSITION INTO SERVICE

(a)     No matter whether the competent authority has decided to review the notified change or not, the service provider should not start the implementation of any part of the change that has the potential to affect the safety of any of the services it provides, e.g. the functions performed or the performance of the services, until it has produced a valid argument in accordance with ATS.OR.205(a)(2) or/and ATM/ANS.OR.C.005(a)(2), as appropriate.

(b)     Implementation of the change, which means the creation and installation of the items to be used in the changed operational system may or may not affect the performance of the current services offered by the service provider. For example, much of the implementation of equipment and procedures can be performed ‘off line’, i.e. in development facilities that do not interact with the operational services and installation may be started, provided the items are not connected to the operational system and their presence in the operational environment does not affect the current services. However, these items must not be introduced into the operational system, i.e. they must not affect the behaviour of any operational service, until a valid assurance case exists and, if the change is subject to competent authority review, before the competent authority has approved the change.

(c)      The installation of an artefact may have an impact on services other than the service being changed. This can happen where the installation involves disrupting these other services, e.g. aerodrome operations may be disrupted because runways or taxiways are being used by constructor’s vehicles or are being interfered with. In this case, the scope of the change includes these other services (please refer to ATM/ANS.OR.C.005(a)(1)(iii) & (iv) or ATS.OR.205(a)(1)(iii) & (iv), as appropriate) and the assessment of the change includes the effects installation may have on them, including where the installation does not go according to plan.