Narrative:

We were getting moderate turbulence. Our flight plan indicated that there was moderate turbulence between FL310 and FL380. We had the performance to reach FL390 so we asked for that altitude. We were held down awhile because of other traffic in the area. ATC eventually cleared us to FL390. We climbed to that altitude; getting moderate turbulence the whole way up. At the same time we asked for a left deviation to stay away from some weather on the radar; which was approved by ATC. As we reached FL390; the turbulence did not get any better. We asked ATC about rides ahead. He queried another aircraft about 40 NM ahead of us who stated light turbulence. We then went from moderate to severe turbulence. The first officer selected mct (max cruise thrust) power momentarily; until he remembered that mct did not give any more engine power at that altitude and returned the thrust levers to the climb detent. The turbulence became so bad that the autopilot clicked off. The first officer manually flew the aircraft. The first officer tried selecting the autopilot on a few times but it would not remain on. The turbulence then went from severe to extreme and we got an ECAM message that disconnected the auto throttles. The captain stated that the number one EPR gauge had blanked; the first officer looked over and saw that the EPR number 1 gauge had blanked and that we did have an ECAM message; but immediately went back to flying the aircraft. As the flying pilot the first officer was so consumed with keeping the aircraft flying that he didn't have time to process what the ECAM was. The turbulence became so extreme the first officer had trouble holding altitude without losing airspeed. The first officer selected toga power in hopes to hold altitude and stop the loss in airspeed which was just above vls (lowest selectable speed). It became apparent to the first officer that he could have altitude or he could have airspeed; but he could not have both. The first officer told the captain that he could not hold altitude and started a slow descent. It just happened at that point ATC asked us if we were descending. The captain [advised] ATC; [and indicated] that we were descending. The first officer continued to fly the aircraft as the captain oversaw the situation and performed the ECAM procedure; which I remember included selecting the N1 mode selector switches on the overhead panel. At FL365 the first officer was able to hold altitude without losing airspeed and leveled at FL360. The first officer turned on the autopilot and manually controlled the thrust levers. The first officer said I have the aircraft and the radio; and allowed the captain to work the problem and coordinate with ATC; dispatch; and the flight attendants. We set up for a diversion; finished all ECAM items; briefed the approach; and landed without incident.I do not recall what the ECAM was as I was consumed with keeping the aircraft flying. We received the 'priority right' aural two times and I cannot recall the exact reasoning for it. I do not know if we had an engine flame out followed by an auto restart. The turbulence was so violent that we could have had a yawing moment and not noticed it.

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Original NASA ASRS Text

Title: Airbus A319 flight crew reported that due to extreme turbulence they were unable to maintain altitude or speed.

Narrative: We were getting moderate turbulence. Our flight plan indicated that there was moderate turbulence between FL310 and FL380. We had the performance to reach FL390 so we asked for that altitude. We were held down awhile because of other traffic in the area. ATC eventually cleared us to FL390. We climbed to that altitude; getting moderate turbulence the whole way up. At the same time we asked for a left deviation to stay away from some weather on the radar; which was approved by ATC. As we reached FL390; the turbulence did not get any better. We asked ATC about rides ahead. He queried another aircraft about 40 NM ahead of us who stated light turbulence. We then went from moderate to severe turbulence. The FO selected MCT (Max Cruise Thrust) power momentarily; until he remembered that MCT did not give any more engine power at that altitude and returned the thrust levers to the Climb detent. The turbulence became so bad that the autopilot clicked off. The FO manually flew the aircraft. The FO tried selecting the autopilot on a few times but it would not remain on. The turbulence then went from severe to extreme and we got an ECAM message that disconnected the auto throttles. The Captain stated that the number one EPR gauge had blanked; the FO looked over and saw that the EPR number 1 gauge had blanked and that we did have an ECAM message; but immediately went back to flying the aircraft. As the flying pilot the FO was so consumed with keeping the aircraft flying that he didn't have time to process what the ECAM was. The turbulence became so extreme the FO had trouble holding altitude without losing airspeed. The FO selected TOGA power in hopes to hold altitude and stop the loss in airspeed which was just above VLS (lowest selectable speed). It became apparent to the FO that he could have altitude or he could have airspeed; but he could not have both. The FO told the Captain that he could not hold altitude and started a slow descent. It just happened at that point ATC asked us if we were descending. The Captain [advised] ATC; [and indicated] that we were descending. The FO continued to fly the aircraft as the Captain oversaw the situation and performed the ECAM procedure; which I remember included selecting the N1 Mode selector switches on the overhead panel. At FL365 the FO was able to hold altitude without losing airspeed and leveled at FL360. The FO turned on the autopilot and manually controlled the thrust levers. The FO said I have the aircraft and the radio; and allowed the Captain to work the problem and coordinate with ATC; Dispatch; and the Flight Attendants. We set up for a diversion; finished all ECAM items; briefed the approach; and landed without incident.I do not recall what the ECAM was as I was consumed with keeping the aircraft flying. We received the 'Priority Right' aural two times and I cannot recall the exact reasoning for it. I do not know if we had an engine flame out followed by an auto restart. The turbulence was so violent that we could have had a yawing moment and not noticed it.

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.