A319
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 2059
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Loss Of Aircraft Control
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Diverted; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control
Weather; Aircraft
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.
In cruise at FL390; we encountered extreme turbulence. Due to the rapid violent nature of the event and in an effort to maintain aircraft control; we were unable to maintain altitude at the same time. The F/O was forced to hand fly the recovery due to loss of autopilot and auto throttles. I immediately [advised ATC]. We were eventually given a clearance to FL350 and were able to maintain that altitude while assessing system malfunctions and cabin issues. The portion of the event in which the aircraft was practically impossible to control lasted about 1 minute and resulted in a 3;500 foot altitude loss. During the recovery; the left EPR indicator displayed an amber X; an ECAM for ENG 1 EPR MODE FAULT (AUTO FLT AUTO THR OFF) displayed; 'Priority Right' aural warning sounded twice and the altitude warning horn continuously sounded. Once stabilized; I had the F/O take the aircraft and radios while I addressed the ECAMs; communicated with the cabin; and contacted dispatch via ACARS. After assessing the aircraft state; the severe nature of the incident; and potential unknown injuries; I elected to divert. An ILS approached was briefed and flown by the F/O. After landing; I had the paramedics meet us at the gate for further injury review; but none was needed.Turbulence was forecasted during flight planning to be LT to OCNL MOD FL070-150 and FL310-380. Our planned cruise altitude was FL350. During the flight we encountered LT TURB to 150; LT-MOD TURB 150-300; and MOD TURB to 350. We also deviated around a line of weather to the south of our position in the climb. Once clear of this weather; we asked about FL390 and ATC said it was good around XXX and we could see that 390 would put us mostly on top of the clouds. Taking all of this into account; we elected to climb in an attempt to find a better ride. The ride did not improve. While on ragged tops of the upper level clouds; the turbulence quickly deteriorated to severe then extreme. No significant radar return was displayed in our immediate area.
Airbus A319 flight crew reported that due to extreme turbulence they were unable to maintain altitude or speed.