Flight Crew Air Transport Pilot (ATP)
Ground Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control
Weather
Approaching a West/East line ATC advised a hole several aircraft had flown through as an easy way on filed route. From the south we were cleared deviations and when able direct a fix. At FL340 encountered icing conditions and engaged all anti icing and experienced speed decay at max cruise power. Switched to [different altitude]; no relief. Told First Officer (FO) to call for lower altitude; frequency was busy. Finally speed was below 250 and decaying; moderate to severe turbulence occurred and autopilot disconnected; right wing dropped 45 degrees as right engine surged from 1.4 to 2.4. Hand flew a descending recovery checking TCAS below and called mayday and cardinal altitudes on the way down until ATC contact established. Turned to BERRI fix and arrested descent at FL310; reported no injuries. Wrote up severe turbulence and engine surge parameters in [the log].Lee side of storm downdraft exceeded performance of the airplane.Use lower altitude and greater horizontal clearance.
[Report narrative contained no additional information.]
MD80 Crew reported icing conditions; turbulence; engine surge and inability to maintain altitude at FL340. Crew reported they arrested the descent at FL310.