Narrative:

On jul/tue/06; I came in for my shift at ZOA. I was directed to relieve the oceanic OC3 controller. During the briefing the controller being relieved advised me that air carrier X (on cpdlc/ads) had not yet read back his clearance from FL310 to FL330. This aircraft was approximately 10 mins away from the ZLA boundary and rapidly approaching ZLA airspace. I was briefed that ZLA was in darc and was busy when the ZOA controller had tried to pass the altitude to them -- ZLA had advised ZOA that they would call us back. As soon as I sat down and signed on to the position; I received an uplink undeliverable message on air carrier X. Air carrier X had still not received the clearance. I immediately canceled the cpdlc clearance and issued the same clearance via HF radio. By this time air carrier X was approximately 2-4 mins from the common boundary. I immediately called ZLA and advised the controller of the situation with air carrier X and advised him to show the flight in a block of FL310-FL350 as I could not verify what altitude he was actually at. Upon receiving the clearance via HF radio; I received this reply from air carrier X; 'is cpdlc working tonight sent request through cpdlc received clearance through sfo commercial radio HF.' this is a recurring problem which I firmly believe will contribute to/cause an accident or incident in the ocean one day! I am extremely concerned with the cpdlc/ads failures in the ocean; as I have reported several cpdlc/ads problems and I have not received a response on any of the previous ucr's from management.

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Original NASA ASRS Text

Title: ZOA CTLR DESCRIBED A RECURRING PROB WITH CPDLC-ADS FAILURES.

Narrative: ON JUL/TUE/06; I CAME IN FOR MY SHIFT AT ZOA. I WAS DIRECTED TO RELIEVE THE OCEANIC OC3 CTLR. DURING THE BRIEFING THE CTLR BEING RELIEVED ADVISED ME THAT ACR X (ON CPDLC/ADS) HAD NOT YET READ BACK HIS CLRNC FROM FL310 TO FL330. THIS ACFT WAS APPROX 10 MINS AWAY FROM THE ZLA BOUNDARY AND RAPIDLY APCHING ZLA AIRSPACE. I WAS BRIEFED THAT ZLA WAS IN DARC AND WAS BUSY WHEN THE ZOA CTLR HAD TRIED TO PASS THE ALT TO THEM -- ZLA HAD ADVISED ZOA THAT THEY WOULD CALL US BACK. AS SOON AS I SAT DOWN AND SIGNED ON TO THE POS; I RECEIVED AN UPLINK UNDELIVERABLE MESSAGE ON ACR X. ACR X HAD STILL NOT RECEIVED THE CLRNC. I IMMEDIATELY CANCELED THE CPDLC CLRNC AND ISSUED THE SAME CLRNC VIA HF RADIO. BY THIS TIME ACR X WAS APPROX 2-4 MINS FROM THE COMMON BOUNDARY. I IMMEDIATELY CALLED ZLA AND ADVISED THE CTLR OF THE SITUATION WITH ACR X AND ADVISED HIM TO SHOW THE FLT IN A BLOCK OF FL310-FL350 AS I COULD NOT VERIFY WHAT ALT HE WAS ACTUALLY AT. UPON RECEIVING THE CLRNC VIA HF RADIO; I RECEIVED THIS REPLY FROM ACR X; 'IS CPDLC WORKING TONIGHT SENT REQUEST THROUGH CPDLC RECEIVED CLRNC THROUGH SFO COMMERCIAL RADIO HF.' THIS IS A RECURRING PROB WHICH I FIRMLY BELIEVE WILL CONTRIBUTE TO/CAUSE AN ACCIDENT OR INCIDENT IN THE OCEAN ONE DAY! I AM EXTREMELY CONCERNED WITH THE CPDLC/ADS FAILURES IN THE OCEAN; AS I HAVE RPTED SEVERAL CPDLC/ADS PROBS AND I HAVE NOT RECEIVED A RESPONSE ON ANY OF THE PREVIOUS UCR'S FROM MGMNT.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.