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Md-11 flight crew reported encountered severe turbulence causing the airspeed to fluctuate below the desired airspeed.
| Attributes | |
| ACN | 1485158 |
| Time | |
| Date | 201709 |
| Local Time Of Day | 0001-0600 |
| Place | |
| Locale Reference | ZZZZ.Airport |
| State Reference | FO |
| Environment | |
| Flight Conditions | IMC |
| Aircraft 1 | |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Generator Drive |
| Person 1 | |
| Function | Pilot Flying Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Person 2 | |
| Function | Pilot Not Flying First Officer |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Speed All Types Inflight Event / Encounter Weather / Turbulence |
Narrative:
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.
Original NASA ASRS Text
Title: MD-11 flight crew reported encountered severe turbulence causing the airspeed to fluctuate below the desired airspeed.
Narrative: 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.
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.