B777-200
Flight Crew Air Transport Pilot (ATP)
Time Pressure; Troubleshooting; Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Procedure; ATC Equipment / Nav Facility / Buildings
Oceanic Clearance Delivery CPDLC late logon due to equipment glitch. [We] complied with B777 Datalink Comm Guide as per reversion to voice procedures. Scottish [Control] was upset we did not obtain our oceanic crossing clearance 30 minutes prior to coast out; which is not what the 15 minutes indicated on the form states. All issues were resolved and the crossing was otherwise uneventful.ATC failure to communicated with the aircraft CPDLC systems on scheduled time.
When CPDLC communications failed a B777 crew reverted to voice comm to receive their oceanic clearance.