37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 1561673 |
Time | |
Date | 201807 |
Local Time Of Day | 0601-1200 |
Place | |
Locale Reference | OMDB.Airport |
State Reference | FO |
Environment | |
Flight Conditions | VMC |
Aircraft 1 | |
Make Model Name | MD-11 |
Operating Under FAR Part | Part 121 |
Flight Phase | Descent |
Route In Use | STAR IMPED 3C |
Flight Plan | IFR |
Aircraft 2 | |
Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
Person 1 | |
Function | Captain Pilot Flying |
Qualification | Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine |
Events | |
Anomaly | Deviation - Procedural Published Material / Policy Deviation - Speed All Types Inflight Event / Encounter Wake Vortex Encounter |
Narrative:
On a published section of the imped 3C STAR; near point DB520. We were descending to 8000 ft. And had slowed to 230 KIAS directed by ATC. Autopilot was engaged. Passing through 9000 ft.; we encountered what felt like wake turbulence from a preceding aircraft. The aircraft began an abrupt left bank; throttles were at idle. I thought the autopilot would correct the attitude; but when we reached about 30 degrees of bank; I disconnected the autopilot and began to roll right to wings level. I didn't catch it in time and the pilot monitoring (pm) noticed on his pfd that a momentary over bank warning displayed. At the time I began rolling back to wings level; the stick shaker momentarily activated. Our minimum clean wing speed was 210 KIAS and we were holding 230 KIAS. That did not make sense to me; but I simultaneously reduced pitch and increased power; but I failed to cross check my angle of attack indicator. I never believed we were airspeed critical and not sure why we had a momentary stick shaker. Once I got the airplane back to wings level and back on course; autopilot was re-engaged and worked normally the rest of the flight. An aircraft behind us reported a similar event. Another reason for this report was that I failed to write up this event. We had 2 hot brakes after landing which we wrote up; and I forgot to check the fom at the aircraft. Once at the hotel; I checked the fom and realized my mistake. I tried calling the ramp; but couldn't get through; so I notified the chief pilot. I completed the write up over the phone with a maintenance representative. The aircraft had already departed dubai.cause: either high altitude windshear/turbulence or wake turbulence from preceding aircraftsuggestions: I don't think a flying event like this can be eliminated because of environmental events. My mistake in not writing up this event had to do with not having time in a congested area to make a write up when it happened and then forgetting the event after landing. Probably a better personal discipline to research/recollect everything before leaving the aircraft.
Original NASA ASRS Text
Title: MD-11 Captain reported encountering wake turbulence on arrival into OMDB.
Narrative: On a published section of the IMPED 3C STAR; near point DB520. We were descending to 8000 ft. and had slowed to 230 KIAS directed by ATC. Autopilot was engaged. Passing through 9000 ft.; we encountered what felt like wake turbulence from a preceding aircraft. The aircraft began an abrupt left bank; throttles were at idle. I thought the autopilot would correct the attitude; but when we reached about 30 degrees of bank; I disconnected the autopilot and began to roll right to wings level. I didn't catch it in time and the Pilot Monitoring (PM) noticed on his PFD that a momentary over bank warning displayed. At the time I began rolling back to wings level; the stick shaker momentarily activated. Our minimum clean wing speed was 210 KIAS and we were holding 230 KIAS. That did not make sense to me; but I simultaneously reduced pitch and increased power; but I failed to cross check my Angle of Attack indicator. I never believed we were airspeed critical and not sure why we had a momentary stick shaker. Once I got the airplane back to wings level and back on course; autopilot was re-engaged and worked normally the rest of the flight. An aircraft behind us reported a similar event. Another reason for this report was that I failed to write up this event. We had 2 hot brakes after landing which we wrote up; and I forgot to check the FOM at the aircraft. Once at the hotel; I checked the FOM and realized my mistake. I tried calling the ramp; but couldn't get through; so I notified the chief pilot. I completed the write up over the phone with a maintenance representative. The aircraft had already departed Dubai.Cause: Either high altitude windshear/turbulence or wake turbulence from preceding aircraftSuggestions: I don't think a flying event like this can be eliminated because of environmental events. My mistake in not writing up this event had to do with not having time in a congested area to make a write up when it happened and then forgetting the event after landing. Probably a better personal discipline to research/recollect everything before leaving the aircraft.
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.