Phase two of the reduced lateral separation minimums (RLatSM) expansion plan in the North Atlantic Tracks (NATs) was to start on Thursday, but that plan is delayed, probably to next year. The initial phase of RLatSM from 50 nm to 25 nm in the NAT system was introduced in December last year. Since then, there has been the option for appropriately equipped aircraft to use one of the three new RLatSM routes.

Under phase two, all routes above FL350 will have the reduced lateral spacing, leaving only a couple of tracks—spaced at 50 nm—for everyone else. A recent NATs Op Bulletin announced the delay, adding, “At least two months’ notice will be given in advance of the new start date.”

The bulletin emphasized that RLatSM phase two is still planned to be implemented in portions of the Gander, Shanwick and Reykjavik Oceanic Control Areas. The bulletin does not provide a reason for the delay, but according to the flight-planning company Flight Service Bureau, “There are some issues that Gander, Shanwick, and Iceland have to work through before their systems are ready to handle the next stage."