MD-11
Flight Crew Air Transport Pilot (ATP)
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
Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Aircraft; Human Factors; Weather
Enroute to [destination] at FL 380; we were instructed by ATC to maintain an airspeed in order to cross a fix [on the airspace] boundary [at a specific time]. We programmed our FMS and the RTA (required time of arrival) airspeed it calculated was 0.778M. We then received a level 2 Generator 2 OFF alert. As we worked the problem; we encountered moderate to severe turbulence. This caused our airspeed to fluctuate and decrease to approximately 5 knots below the bottom foot. I immediately pushed he throttles to max thrust to accelerate the airspeed and we subsequently flew out of the turbulence. The airplane was in autopilot mode the whole time. The airplane momentarily gained 500-800 feet of altitude due to the updrafts; but we quickly and safely corrected to our assigned altitude after the brief turbulence encounter. We advised ATC of our situation and we took a heading to avoid weather build-ups which were in front of us. Upon landing; we wrote up the turbulence encounter in the logs.
[Report narrative contained no additional information.]
MD-11 flight crew reported encountered severe turbulence causing the airspeed to fluctuate below the desired airspeed.