Both Gander and Shanwick oceanic control areas (OCAs) are conducting a trial of reduced longitudinal separation standards–five minutes between eligible aircraft–in North Atlantic airspace. The separation minimum for turbojets maintaining constant Mach on the same longitudinal track in the North Atlantic minimum navigation performance specifications (MNPS) airspace is 10 minutes.
To be eligible to participate, aircraft must have a flight plan, use automatic dependent surveillance-contract (ADS-C) and direct controller pilot communications (DCPC) provided via controller–pilot datalink communications (CPDLC). In addition, the flights must have reported passing a common point from which they follow the same or continuously diverging routes.
The five-minute longitudinal separation minimum used in the trial becomes available once eligible aircraft have entered the Gander or Shanwick OCA and a properly equipped aircraft establishes a datalink connection with ATC.
Operators do not need to apply to be part of the trial, only request a change in altitude, be properly equipped, and have MNPS approval. The rest of the process should be transparent to flight crews. The strategic lateral offset procedure (SLOP) is unaffected.