Narrative:

While flying in cruise I requested a dispatch update from ACARS. When reviewing it; it show no position fuel reported to dispatch by showing a dash next to the oceanic position instead of the a next to the position; even though we had passed over the position not abeam it. We were on a re-dispatch release; not a reserve release; so this was not a regulatory issue but in investigating we discovered the ACARS had dumped its initialization page which caused the aircraft not to report or accept ACARS messages. There is no notification to the pilot when/if this occurs other than troubleshooting when not receiving a response for an ACARS request or as I routinely do; look at the update to be sure dispatch is receiving fuel reports. We had received all ETOPS required information; so the initialization dump had occurred after oceanic entry and after ETOPS weather was received. We did not write this up in aircraft log book as this has happened to me about 4 times in the last 3 weeks; and appears not to be an aircraft specific issue but more of a system systemic issue as it has occurred to me on different 777 aircraft. I sent messages to the dispatcher telling him I was going to file a report and he indicated this has been an issue recently. The concerns I have is the flight following threat with dispatch not able to contact the flight via satcom ACARS; also the security issues of immediate security messages sent through ACARS; and possible inability to receive ACARS clearances for oceanic entry. I encouraged the dispatcher to file a report as well; to determine if this is a fleet specific issue to the 777 related to the automatic init function of ACARS; dispatch software; or hardware issue with the flight following equipment.

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Original NASA ASRS Text

Title: A B777 Captain reported that at some point after oceanic track entry; the ACARS dropped its initialization which prevented the aircraft from sending and receiving ACARS reports including Dispatch messages; fuel reports; and other critical communications.

Narrative: While flying in cruise I requested a Dispatch update from ACARS. When reviewing it; it show no position fuel reported to Dispatch by showing a dash next to the oceanic position instead of the A next to the position; even though we had passed over the position not abeam it. We were on a re-dispatch release; not a reserve release; so this was not a regulatory issue but in investigating we discovered the ACARS had dumped its initialization page which caused the aircraft not to report or accept ACARS messages. There is no notification to the pilot when/if this occurs other than troubleshooting when not receiving a response for an ACARS request or as I routinely do; look at the update to be sure Dispatch is receiving fuel reports. We had received all ETOPS required information; so the initialization dump had occurred after oceanic entry and after ETOPS weather was received. We did not write this up in aircraft log book as this has happened to me about 4 times in the last 3 weeks; and appears not to be an aircraft specific issue but more of a system systemic issue as it has occurred to me on different 777 aircraft. I sent messages to the Dispatcher telling him I was going to file a report and he indicated this has been an issue recently. The concerns I have is the flight following threat with Dispatch not able to contact the flight via SATCOM ACARS; also the security issues of immediate security messages sent through ACARS; and possible inability to receive ACARS clearances for oceanic entry. I encouraged the Dispatcher to file a report as well; to determine if this is a fleet specific issue to the 777 related to the AUTO INIT function of ACARS; dispatch software; or hardware issue with the flight following equipment.

Data retrieved from NASA's ASRS site as of July 2013 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.