Captain exercises his emergency authority to deviate around a thunderstorm on the north atlantic tra...

Narrative:

Shortly after returning from my rest period (2nd break); we were at FL350; slop [strategic lateral offset program] R1 off track west. We saw green and yellow radar returns indicating thunderstorms (trw) building ahead; with tops at/near our altitude on our route of flight. After evaluation we determined that we needed to deviate altitude or course to avoid possible turbulence and adverse weather. [We] requested cpdlc altitude change to climb above radar returns (yellow/green) ahead. Shortly after requesting; shanwick's cpdlc response was 'unable due to traffic'. [We] continued on slop R1 analyzing weather and options. Determined I needed to utilize emergency authority to deviate. Eight minutes later began deviation from R1 slop to R12 to remain clear of buildups/cloud ceiling/yellow radar returns directly ahead. Focus was outside looking for possible aircraft and monitoring track/course deviation. Five minutes later sent cpdlc free text message; 'DV8ing 12 south for trw.' [we] remained at FL350. Transmitted on 123.45 our position; altitude and deviation distance off track west. Received two selcal's from shanwick; but upon attempting to communicate; shanwick was unreadable. (Solar storm was impacting HF.) several minutes later; answered another selcal and was advised that shanwick 'was filing' on the incident because our deviation had violated standard separation with two other aircraft. I asked for the flight numbers of the other flights; which was provided. Requested separation distances and after several minutes; was told 'shanwick is too busy. It will be in the report.' contacted these flights and plotted their positions at the time in question. (Note: all aircraft 'involved' were at FL350; mach .83.) [there appeared to be no loss of separation.] we were in day VMC at all times; just above a cloud deck and deviating to the right of the trw; lights on; at FL350. 'Aviate; navigate; communicate' priorities dictated that we avoid the cells as our first priority; and maintain traffic watch as a second priority. Contacted dispatch on satellite phone and informed them of situation. They indicated that they had received some message traffic on the incident.

Original NASA ASRS Text

Title: Captain exercises his emergency authority to deviate around a thunderstorm on the North Atlantic Tracks; after a request to Shanwick Oceanic via CPDLC is denied. Shanwick indicated that a loss of standard separation occurred during this incident.

Narrative: Shortly after returning from my rest period (2nd break); we were at FL350; SLOP [strategic lateral offset program] R1 off Track W. We saw green and yellow radar returns indicating thunderstorms (TRW) building ahead; with tops at/near our altitude on our route of flight. After evaluation we determined that we needed to deviate altitude or course to avoid possible turbulence and adverse weather. [We] requested CPDLC altitude change to climb above radar returns (yellow/green) ahead. Shortly after requesting; Shanwick's CPDLC response was 'Unable due to traffic'. [We] continued on SLOP R1 analyzing weather and options. Determined I needed to utilize emergency authority to deviate. Eight minutes later began deviation from R1 SLOP to R12 to remain clear of buildups/cloud ceiling/yellow radar returns directly ahead. Focus was outside looking for possible aircraft and monitoring track/course deviation. Five minutes later sent CPDLC free text message; 'DV8ing 12 south for TRW.' [We] remained at FL350. Transmitted on 123.45 our position; altitude and deviation distance off Track W. Received two SelCal's from Shanwick; but upon attempting to communicate; Shanwick was unreadable. (Solar storm was impacting HF.) Several minutes later; answered another SelCal and was advised that Shanwick 'was filing' on the incident because our deviation had violated standard separation with two other aircraft. I asked for the flight numbers of the other flights; which was provided. Requested separation distances and after several minutes; was told 'Shanwick is too busy. It will be in the report.' Contacted these flights and plotted their positions at the time in question. (Note: All aircraft 'involved' were at FL350; Mach .83.) [There appeared to be no loss of separation.] We were in day VMC at all times; just above a cloud deck and deviating to the right of the TRW; lights on; at FL350. 'Aviate; navigate; communicate' priorities dictated that we avoid the cells as our first priority; and maintain traffic watch as a second priority. Contacted Dispatch on Satellite Phone and informed them of situation. They indicated that they had received some message traffic on the incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	964149
Time
Date	201108
Local Time Of Day	0601-1200
Place
Locale Reference	EGGX.ARTCC
State Reference	FO
Aircraft 1
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 27000 Flight Crew Type 2450
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types Inflight Event / Encounter Weather / Turbulence

Captain exercises his emergency authority to deviate around a thunderstorm on the north atlantic tracks; after a request to shanwick oceanic via cpdlc is denied. Shanwick indicated that a loss of standard separation occurred during this incident.