Narrative:

We were deviating around a line of thunderstorms in the descent to newark just before the incident occurred. During the descent and deviation; I (as pilot flying) had temporarily slowed to 280 KIAS despite being asked by ATC to speed up to 300 KIAS because I suspected we might encounter rough air. We also instructed the flight attendants to clean up the cabin and take their seats. We completed our deviation around the storms and began proceeding directly to somto intersection in VMC. We were given a clearance to continue our descent to 11;000 ft; and a request to expedite the descent. We then entered a small area of IMC and were passing about 13;000 ft in the descent when the incident happened. I was in lvl chg (idle descent) with the speed brakes extended; on autopilot. The radar showed no precipitation at all nor any convective activity along our route of flight. There were only a few scattered; small (2-5 mile diameter) rain showers in the area; with nothing showing heavier than the lowest level of returns (green on the display). The radar was in WX/turbulence mode and appeared to be working properly. Earlier in the descent it had properly showed each level of return while we were deviating around the line of thunderstorms. Shortly after we entered the clouds; we hit several very hard jolts of turbulence; significantly bouncing the airplane around. We heard objects hitting the floor in the forward galley and the plane was bounced around up to 15 degrees of bank. There was a momentary pause between the first jolt and later bumps and I actually thought we might have simply hit some wake turbulence since nothing was showing on the radar. The bumps continued for around 30 seconds so it was obviously some sort of convective activity. Shortly after the turbulence stopped; we exited the clouds and could see cumulus cloud formations around us that had caused the rough air. During the event; the aft entry warning light came on; although there was no change in cabin pressure. I took the radios while the captain called to the back to check on the status of the cabin. At the time; one flight attendant said her back was hurting; but that she would not require medical attention; and we were not told of any further injuries. Another flight attendant; who was collecting trash in the aisle when the event occurred; discovered when she returned to the aft galley that the aft left exit door handle had come slightly open during the event. She pushed it back down; and the light extinguished. We continued our descent; approach; and landing into newark. After landing; we were told we had one passenger who had hit his head in the incident; so we asked to have the paramedics meet the flight. After deplaning the passengers; the flight attendant whose back was hurt accepted a ride to the hospital for evaluation. She did seem to be having a great deal of difficulty walking and seemed to be in significant pain. The passenger had been treated with ice on the bump on his head and I think he left on his own after being checked by the paramedics and did not go to the hospital. The seat belt sign had been illuminated for quite some time; and we had told the flight attendants to clean up the cabin and take seats about 10 minutes before we had the incident. We did not believe there was any chance of damage to the aircraft because we did not feel that the G forces we experienced were anywhere near the limits for the aircraft; and because we were flying at the turbulent air penetration speed when the event occurred. Flight into an area of severe convective turbulence that was not displayed on the on-board weather radar with flight attendants and one passenger not seated and secured by seat belts. Since we had no warning of the existence of the cells producing that turbulence; I can only suggest that we insist that the flight attendants be seated any time the flight will be in IMC within 10 or more miles of major convective activity.

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Original NASA ASRS Text

Title: A B737 approaching EWR encountered undetected convective activity descending through 13;000 to 11;000 FT injuring a Flight Attendant and passenger.

Narrative: We were deviating around a line of thunderstorms in the descent to Newark just before the incident occurred. During the descent and deviation; I (as pilot flying) had temporarily slowed to 280 KIAS despite being asked by ATC to speed up to 300 KIAS because I suspected we might encounter rough air. We also instructed the flight attendants to clean up the cabin and take their seats. We completed our deviation around the storms and began proceeding directly to SOMTO intersection in VMC. We were given a clearance to continue our descent to 11;000 FT; and a request to expedite the descent. We then entered a small area of IMC and were passing about 13;000 FT in the descent when the incident happened. I was in LVL CHG (idle descent) with the speed brakes extended; on autopilot. The radar showed no precipitation at all nor any convective activity along our route of flight. There were only a few scattered; small (2-5 mile diameter) rain showers in the area; with nothing showing heavier than the lowest level of returns (green on the display). The radar was in WX/TURB mode and appeared to be working properly. Earlier in the descent it had properly showed each level of return while we were deviating around the line of thunderstorms. Shortly after we entered the clouds; we hit several very hard jolts of turbulence; significantly bouncing the airplane around. We heard objects hitting the floor in the forward galley and the plane was bounced around up to 15 degrees of bank. There was a momentary pause between the first jolt and later bumps and I actually thought we might have simply hit some wake turbulence since nothing was showing on the radar. The bumps continued for around 30 seconds so it was obviously some sort of convective activity. Shortly after the turbulence stopped; we exited the clouds and could see cumulus cloud formations around us that had caused the rough air. During the event; the AFT ENTRY warning light came on; although there was no change in cabin pressure. I took the radios while the Captain called to the back to check on the status of the cabin. At the time; One Flight Attendant said her back was hurting; but that she would not require medical attention; and we were not told of any further injuries. Another Flight Attendant; who was collecting trash in the aisle when the event occurred; discovered when she returned to the aft galley that the aft left exit door handle had come slightly open during the event. She pushed it back down; and the light extinguished. We continued our descent; approach; and landing into Newark. After landing; we were told we had one passenger who had hit his head in the incident; so we asked to have the paramedics meet the flight. After deplaning the passengers; the flight attendant whose back was hurt accepted a ride to the hospital for evaluation. She did seem to be having a great deal of difficulty walking and seemed to be in significant pain. The passenger had been treated with ice on the bump on his head and I think he left on his own after being checked by the paramedics and did not go to the hospital. The seat belt sign had been illuminated for quite some time; and we had told the flight attendants to clean up the cabin and take seats about 10 minutes before we had the incident. We did not believe there was any chance of damage to the aircraft because we did not feel that the G forces we experienced were anywhere near the limits for the aircraft; and because we were flying at the turbulent air penetration speed when the event occurred. Flight into an area of severe convective turbulence that was not displayed on the on-board weather radar with flight attendants and one passenger not seated and secured by seat belts. Since we had no warning of the existence of the cells producing that turbulence; I can only suggest that we insist that the flight attendants be seated any time the flight will be in IMC within 10 or more miles of major convective activity.

Data retrieved from NASA's ASRS site as of April 2012 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.