OpsGroup has advised its international operator members of four new ICAO bulletins updating North Atlantic Track (NAT) operations. The first bulletin (2019-001) formalizes a practice that has been in place since April in the Shanwick, Santa Maria, and New York Oceanic FIRs. After receiving a clearance with a fixed Mach number, expect that over the oceanic entry point, a CPDLC message could be received saying “resume normal speed.” If that speed varies by 0.02 Mach or more, ATC must be advised.
Advanced surveillance enhanced procedural separation (ASEPS) trials started in April in the Shanwick, Gander, and Santa Maria FIRs for longitudinal separation down to 14 nm. Under bulletin 2019-002, starting in October lateral separation for compliant aircraft drops to 19 nm from the previous limit of 25 nm. According to OpsGroup, “The initial benefit will basically be that steeper route angles will now be available for pairs of aircraft flying parallel routes outside of the NAT.”
NAT bulletin 2019-003 lists common datalink errors and explains what to do about them. OpsGroup said the takeaways from this are to update avionics software as soon as updates are available and answer datalink messages within 60 seconds, even if with a standby message. “Recent data indicates business aviation operators are very bad at this,” said OpsGroup.
The last notice, a revision to bulletin 2017-001, caps the datalink mandate altitude. Beginning Jan. 30, 2020, datalink communications will be required between FL290 and FL410. With this revision, non-compliant aircraft will be able to operate at FL430 and above.