Navigate / EASA
GM6 SERA.11014  ACAS resolution advisory (RA)

ED Decision 2016/023/R

Unless informed by the pilot, ATC does not know when ACAS issues RAs. It is possible for ATC to issue instructions that are unknowingly contrary to ACAS RA indications. Therefore, it is important that ATC be notified when an ATC instruction or clearance is not being followed because it conflicts with an RA.