B737 flight crew reported an aircraft loss of control due to turbulence while descending on approach. The Captain recovered the aircraft and landed safely with no injuries or damage to the aircraft.
Synopsis
B737 flight crew reported an aircraft loss of control due to turbulence while descending on approach. The Captain recovered the aircraft and landed safely with no injuries or damage to the aircraft.
Narrative
2NM W ZZZZZ; we experienced extreme turbulence at 4;000' MSL. The aircraft rolled right approximately greater than 60-degrees of bank. There was no weather indication that this should have occurred. No clouds were present in the area and the winds aloft were no greater than 20-knots. The Captain (PF) correctly applied a maximum aileron input full left. After one or two seconds; the aircraft quickly rolled left. It felt as if the aircraft was not responding to the aileron input which made both the Captain and I extremely uneasy. We both remarked that we had felt nothing like it in both our flying careers. As the aircraft was recovering; it also felt like the yaw damper had failed and the aircraft was flailing around the sky in an uncoordinated manner. That persisted for a few seconds during and after the recovery. We proceeded to fly a normal approach to land after correcting back onto the localizer. We wrote the aircraft up for an extreme turbulence event (given the loss of control) and notified Dispatch once on the ground. ATC was also notified of the incident.Suggestions: It would have been a good idea to make a PA to the passengers once on the ground. If time allowed which it probably did; it would have been good to check to make sure the F/As were OK; too.
Second reporter narrative
The flight was from ZZZ1 to ZZZ. We were cleared to ZZZZZ intersection to cross at 3;000 ft. cleared for ILS XX. About ten miles from ZZZZZ we hit a moderate jolt that shoved the aircraft to the right. No pitch no roll just a sideways shove. FO (name) said he actually felt his seat slide sideways underneath him. Approaching ZZZZZ the aircraft rolled 60 to 70 degrees right maybe more. I disconnected the autopilot and applied full left aileron to the stop and the aircraft did not respond for about three seconds. I seriously thought we might continue to roll right and become inverted. The aircraft was not responding to my left roll input. We began to roll towards level flight while the severe turbulence continued with nose up nose down five to eight degrees while rolling left and right. The whole event lasted about 15 seconds. When we exited the turbulence into mostly smooth air. We had just been handed off to ZZZ Tower just prior to encountering the turbulence. I had the FO contact Tower and give a report and to request a wind check. The winds were reported at 170 at 10 knots. We continued the approach in mostly smooth air to a normal landing. I should have called the Flight Attendants but in reality; I was waiting for another encounter; and it was time to drop the gear and land. I spoke with the flight attendants after landing. They were not injured and none of the Passengers were injured. One of the F/As said she had been flying for 38 years and had never felt anything like that. She told the F/A sitting next to her that this is it". I called Dispatch and was conferenced with the Operations Chief Pilot and Maintenance. I made a logbook entry switched aircraft and continued to ZZZ."
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.