Narrative:

I was the relief pilot flying with the captain in the left seat as pilot not flying. We copied a convective SIGMET in the vicinity of lpla. As we approached a line of severe weather we requested a deviation via cpdlc. No response from lppo. We contacted santa maria on HF for an altitude change (climb) and a course deviation (left/north). Our request was denied. The captain immediately directed me to take action to avoid a red radar return. I took a 45 degree cut away to the left as the captain declared a pan; pan; pan and told me to descend 300 ft. We broadcast emergency advisories on VHF and HF; turned on all lights and called santa maria on HF. We deviated about 50 NM left of course. We avoided all weather then cut back to fly direct on track at 30W where we reported back on track. Two other aircraft contacted us during our deviation. We arrived at 30W four minutes late. We complied with all standard mnpsa [minimum navigation performance specification airspace] procedures. I sent dispatch a message reporting continuous moderate chop and that we had deviated. The captain took the correct actions to avoid severe weather. The flight continued without incident. We should not dispatch aircraft into conditions of severe weather or else have dispatch give aircraft sufficient warning so as to coordinate a reroute before we have to deviate without clearance. We should not send multiple north atlantic flights on the exact same routes so that a deviation cannot be coordinated with ATC because there are too many flights in close proximity.

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Original NASA ASRS Text

Title: A B767-300 flight crew had to declare an emergency in order to avoide severe weather in the North Atlantic.

Narrative: I was the Relief Pilot flying with the Captain in the left seat as pilot not flying. We copied a convective SIGMET in the vicinity of LPLA. As we approached a line of severe weather we requested a deviation via CPDLC. No response from LPPO. We contacted Santa Maria on HF for an altitude change (climb) and a course deviation (left/north). Our request was denied. The Captain immediately directed me to take action to avoid a red radar return. I took a 45 degree cut away to the left as the Captain declared a PAN; PAN; PAN and told me to descend 300 FT. We broadcast emergency advisories on VHF and HF; turned on all lights and called Santa Maria on HF. We deviated about 50 NM left of course. We avoided all weather then cut back to fly direct on track at 30W where we reported back on track. Two other aircraft contacted us during our deviation. We arrived at 30W four minutes late. We complied with all standard MNPSA [MINIMUM NAVIGATION PERFORMANCE SPECIFICATION AIRSPACE] procedures. I sent Dispatch a message reporting continuous moderate chop and that we had deviated. The Captain took the correct actions to avoid severe weather. The flight continued without incident. We should not dispatch aircraft into conditions of severe weather or else have Dispatch give aircraft sufficient warning so as to coordinate a reroute before we have to deviate without clearance. We should not send multiple North Atlantic flights on the exact same routes so that a deviation cannot be coordinated with ATC because there are too many flights in close proximity.

Data retrieved from NASA's ASRS site 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.