There are 3 elements to an oceanic clearance: Route, Level, and Speed. These provide the 3 basic elements of separation: lateral, vertical, and longitudinal.
Since Mar 2024 flight crews have no longer been required to be in receipt of an Oceanic Clearance prior to crossing the Oceanic Entry Point (OEP). The Request for Clearance (RCL) message requirements for all areas other than New York (which remain unchanged) is be covered below.
It has been enabled through significant advancements in Communications, Navigation and Surveillance technology resulting in improved safety and service.
Controller Pilot Data Link Communications (CPDLC) enables the exchange of messages directly and swiftly between ATC and the flight crews including loadable route clearance uplinks.
The CPDLC confirm assign route message enables the ATC flight data processors to conformance check the full route loaded in the flight management computer (FMC) alerting the controllers when there is or going to be a deviation.
Automatic Dependent Surveillance – Contract (ADS-C) uses data link to transmit information directly from an aircraft’s FMC to ATC flight data processors. Contracts are established so that the avionics reports the aircraft’s current. next, and next +1 positions loaded into the FMC at regular intervals alerting ATC if there is a deviation from the cleared profile.
Ground and space based ATS surveillance including radar and Automatic Dependent Surveillance – Broadcast (ADS-B) enables ATC to track aircraft progress in near real time alerting ATCOs in a matter of seconds should a flight crew select a change of level or deviate from cleared route without instruction from ATC.
After the removal of the Oceanic Clearance, the process formerly known as the Request for Clearance process is now simply referred to the RCL will continue to be utilised through ACARS or voice to ensure that ATC planning flights into the NAT region consider the most up to date flight crew requests at the OEP.
The RCL must contain the following information:
- Requested OEP
- ETA for the OEP
- Mach Number (based on FMS Cost Index (ECON))
- Requested FL at OEP
- Highest (MAX) level at OEP
If no Max level is given ATC will take the requested level as the Max level at the OEP.
ACARS is the primary method for flight crews to send the RCL to ATC responsible for the first Oceanic Control Area where the aircraft will enter the NAT Region. Voice remains available as detailed within State AIP publications.
ATC will automatically uplink a preformatted confirmation of response message. When the RCL is submitted via voice an equivalent response is transmitted to the flight crew. There will be no requirement for the flight crew to remain on the Oceanic clearance frequency unless instructed to do so by ATC. On receipt of the RCL from the flight crew Oceanic ATC will use the information provided to plan the flight into the NAT Region and will coordinate with Domestic ATC responsible for clearing the flight over the OEP. The flight crew must fly what is loaded in the FMC or is amended by ATC.
Voice shall be used:
- Whenever ACARS data link is not operational.
- When the ETA for the OEP is less than the minimum requirements stated in AIPs.
- Upon receipt of an ACARS ‘RCL REJECTED’ or other instruction
- No response to the RCL within 15 minutes of it being sent or when instructed to do so by ATC.
If Oceanic ATC cannot accept the requested OEP FL, the closest FL to the one requested will be determined and a clearance to climb or descend will be issued by ATC prior to the OEP. The Max FL will never be exceeded and if the FL determined by ATC is 3000 ft or greater, then ATC will enter negotiations to find the best alternative.
Traffic situation constantly changes previous blocked FL’s may become available. Oceanic ATC will store the requested FL information provided within the RCL and may issue a subsequent level change after passing the OEP.
Changes in FL or route can be requested at any time after passing the OEP, but you must wait for ATC clearance before changing FL or route.
Domestic ATC are fully responsible for issuing FL changes to ensure the flight crosses the OEP at the correct level.
If Oceanic ATC cannot accept the current flight plan route that is loaded in the FMC including the OEP a route amendment will be issued by either loadable route clearance uplink by CPDLC or Voice prior to reaching the OEP.
For west bound flights that require a route amendment entering the NAT via Shanwick Oceanic the flight crew will be instructed to contact Shanwick ATC by Voice on HF or VHF 123.950 MHz or 127.650 MHz.
Instruction to contact Shanwick ATC by Voice to receive a route amendment will either be delivered to the flight crew by ACARS or Domestic ATC on VHF no less than 30 minutes prior to reaching the OEP.
Speed restrictions will be issued by Domestic ATC prior to the OEP or Oceanic ATC after the OEP. ATC must be advised if speed changes by M0.02 or more from the Mach in the RCL.