Departure Clearance, Oceanic Clearance and D-ATIS
Article 2 split datalink applications into two classes: CPDLC/ADS-C (FANS A) handshake first; DCL/OCL/D-ATIS (ATS 623) do not. This article covers the second class — three "one-shot, text-based clearance/information" applications: DCL (departure clearance), OCL (oceanic clearance), D-ATIS (digital ATIS). Their common model is article 2's request → clearance/information → read-back → confirmation — like a text query, with no persistent connection.
1. Departure Clearance (DCL)
DCL obtains a departure clearance by datalink on the ground. Per FCOM DSC-46-10-30-40:
The Departure Clearance (DCL) application enables the flight crew to request and obtain departure information and clearance from the ATC center. The DCL application is initiated by: The flight crew, when sending a DCL request; The ATC center, when sending a DCL clearance to the aircraft without a request. Consequently, the flight crew receives the clearance, reads back the clearance and receives the read-back confirmation from the ATC.
The new-clearance alert. Per FCOM DSC-46-10-30-40:
A new message triggers visual (ATC MSG light) and aural alerts. The DCDU displays the new message in an open status, on a blue background. [...] The flight crew can acknowledge or refuse the departure clearance.
DCL is received on the DCDU (a new message on a blue background) — the normal "standard ATC application received on the DCDU", worth holding to contrast with D-ATIS in §3.
2. Oceanic Clearance (OCL)
OCL obtains a clearance to enter oceanic airspace. Per FCOM DSC-46-10-30-50:
The ATS623 Oceanic Clearance (OCL) application enables the flight crew to request and obtain a clearance from the Oceanic ATC center to enter an oceanic airspace. The OCL application can be initiated: When the flight crew sends an OCL request via the MCDU; When the ATC center sends an OCL clearance to the aircraft without a request.
OCL and DCL are the same model, different scene: DCL takes a clearance at the departure aerodrome, OCL takes one at the oceanic boundary. Neither needs the AFN handshake.
3. D-ATIS — digital ATIS
D-ATIS obtains airport information by datalink. Per FCOM DSC-46-10-30-60:
The Digital Automatic Terminal Information Service (D-ATIS) enables the flight crew to request and obtain information about airports. [...] The flight crew can request information for departure, destination, and alternate airports via the ATIS MENU page of the MCDU. When initially accessing the ATIS MENU page, the application automatically fills in the airport names [...] with departure, arrival and alternate airport names (if they are entered via the FMS).
Automatic update. Per FCOM DSC-46-10-30-60:
The AUTO-UPDATE function automatically provides ATIS reports of arrival airports only when a new version is available.
The one point to remember most. Per FCOM DSC-46-10-30-60:
Note: ATIS reports are received in the MCDU, contrary to other ATC datalink applications that receive messages in the DCDU.
[!warning]- D-ATIS is received on the MCDU, not the DCDU Other ATC datalink messages (CPDLC clearances, DCL clearances…) are received on the DCDU (the dedicated datalink display); only D-ATIS reports are received on the MCDU. Why? An ATIS is a long block of text (weather/runway/approach), better read on the MCDU's multi-line pages, whereas the DCDU is for "read one, answer one" short messages. So look for ATIS on the MCDU, not the DCDU. Automatic printing is available (selected on the ATIS MENU page). Remember the exception: ATIS on the MCDU, everything else on the DCDU.
Self-test
[!note]- Q1. What does each of DCL/OCL/D-ATIS obtain, and what is the biggest difference from CPDLC (handshake)? DCL: departure clearance; OCL: oceanic-airspace clearance; D-ATIS: airport information. Unlike CPDLC, they need no notification/connection handshake.
[!note]- Q2. Who initiates DCL/OCL, and what does the crew do on receiving the clearance? Either the crew (request) or ATC (unsolicited clearance); the crew receive, read back, and receive the read-back confirmation.
[!note]- Q3. On which page is D-ATIS requested, how are DEP/ARR types filled, and what does AUTO-UPDATE update, for which airports? On the ATIS MENU page; DEP/ARR are auto-filled from the FMS; AUTO-UPDATE updates arrival airports only, and only when a new version is available.
[!note]- Q4. Why is D-ATIS received on the MCDU rather than the DCDU? An ATIS is a long text block, better read on the MCDU's multi-line pages; the DCDU is for short read-one/answer-one messages.
Key takeaways
| Point | Detail |
|---|---|
| ATS 623 three | DCL / OCL / D-ATIS — one-shot, no handshake |
| DCL / OCL | Request or unsolicited; read back and confirm; received on the DCDU (blue background) |
| D-ATIS | ATIS MENU page; DEP/ARR auto-filled; AUTO-UPDATE (arrival, new version only) |
| Exception | ATIS is received on the MCDU; everything else on the DCDU |
References
- FCOM DSC-46-10-30-40 — DCL request/obtain, crew or ATC initiated, read-back/confirmation, DCDU blue background.
- FCOM DSC-46-10-30-50 — OCL to enter oceanic airspace, crew or ATC initiated.
- FCOM DSC-46-10-30-60 — D-ATIS ATIS MENU, DEP/ARR auto-fill, AUTO-UPDATE, received on the MCDU (exception).
Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use.