Air carrier flight crew reported temporary loss of aircraft control after encountering turbulence near CAMJO Intersection in ZJX airspace.
Synopsis
Air carrier flight crew reported temporary loss of aircraft control after encountering turbulence near CAMJO Intersection in ZJX airspace.
Narrative
Our flight encountered two pop up Weather Cells 20 miles south of CAMJO Intersection. We were originally given clearance to deviate right of course in case we came across weather. The clearance was given to us about 60 miles prior to CAMJO. The Seat Belt sign was on. We were now IMC and both the FO and I were trying to find cells on the weather radar. Neither of us painted anything. As we approached CAMJO; we noticed two cells that seemed to come out of no where. I immediately turned right and in less than 10 seconds we were in one cell trying to work our way best in between them. I did not have enough time to warn the FA's. Literally...the aircraft was fine and then 5 seconds later was not. The event lasted shy of a minute; but we had +/- 800 feet and +/- 20 knots deviations. The autopilot was unable to hold altitude so I turned off the autopilot as it was chasing the command bars on the FD. I was concerned of a potential overspeed if it tried too quickly to descend. The auto-throttles remained on. Once clear of weather; we stabilized the aircraft and the FO checked on them and made sure they were seated. They all had fallen; but were OK and seated. We deviated for a long distance around the line that we saw building/established. The FO checked on them a few more times and one of the FA's said she had banged her knee on the beverage cart. She did not want any medical attention at that time. We sent messages to Dispatch and made a Maintenance write up. The Flight continued uneventfully with a safe landing. After landing; the FA came and spoke to me and I suggested she talk with her supervisor so they could help her seek medical attention if needed due to the swelling.
Second reporter narrative
While level in cruise flight at FL370 near CAMJO; we encountered severe turbulence from heavy precipitation that was not showing on radar. We were in a haze/cloud layer at FL370 and thus could not see anything weather wise visibly in front of us. There was precipitation showing on the radar at CAMJO and we queried ATC about it and deviations. ATC Advised we should be above most weather and that others had deviated right of course due to the weather. We checked both weather apps and both aligned with what was showing on the on board radar; nothing right of course so right deviations were appropriate. We were given deviations 15 degrees right of course; direct HEPAR when able. During our right turn as we were rolling wings level; a thunderstorm cell appeared in front of us that was not showing on radar previously. It did not show on the radar until we were inside the cell. We did not have time to make an announcement to the flight attendants prior to entering the cell and we were immediately in severe turbulence with +/- approximately 800 feet of altitude deviations and +/- 20 knots on the airspeed. The Captain; who was pilot flying; turned off the autopilot to assist in keeping the airplane from over-speeding. After ensuring aircraft control; we advised ATC of the turbulence and I immediately called the flight attendants to check on them. Aircraft control was maintained throughout the event. The seat belt sign was on prior to and throughout the event. The purser advised that all of the flight attendants had fallen but there were no injuries reported at that time. They did say that one flight attendant was hit by the beverage cart but no injuries were initially reported. All passengers were seated and no injuries reported from them as well. We advised dispatch of the turbulence and completed a maintenance logbook report. As we were approaching our destination; the flight attendant working the aft section of the plane called and advised that her knee was starting to swell and hurt from the beverage cart hitting her. She stated she did not need medical attention at the time. After landing we spoke with maintenance personnel and the flight attendant that was hit by the beverage cart. We advised her to report this to her supervisor and to seek medical attention because her knee was starting to swell. The Captain advised he would be completing a report.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.