Date: 201507
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Daylight
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Flight Attendant (On Duty)
Anomaly: Deviation - Speed All Types; Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew; Person Flight Attendant
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Regained Aircraft Control; General Physical Injury / Incapacitation
Contributing factors: Human Factors; Weather
Primary problem: Weather

Narrative: We were in the descent around 30;000 FT; in IMC. Clouds were thin Cirrus. There were T-storms about 20-25 miles to the right; east of us. They were all that showed on the aircraft radar. The flight had been uneventful in all ways. No turbulence was reported or experienced until the event. Then the aircraft experienced instantaneous severe turbulence for about 5 seconds. It felt like hitting pot holes in a fast car with no shocks. Worst episode I have encountered in 34 years of flying. The autopilot roll mode disengaged due to the severity of the event. Aircraft control was impossible for those 5 seconds.  I lowered my head to avoid possible impact with ceiling and watched the instruments.  Aircraft descended and banked left 20-25 degrees. Speed remained constant around 300 KTS. No stall warning; no overspeed clacker but when the turbulence stopped and I tried to level the plane I realized the autopilot was in CWS (Control Wheel Steering).  I disengaged the autopilot; regained control of the aircraft and re-engaged it.  Then we called the cabin crew to assess any injuries. Next we informed ATC of the event. We asked for medical services to meet us at the gate. We got direct clearance to short final and I kept the speed up. I flew 270 KTS for a bit below 10;000 FT. We sent ACARS messages to dispatch in reference to the event. No further turbulence was encountered and the remainder of the flight was uneventful. We were too close to destination to consider medlink or a divert with the injuries the Flight Attendant's described to us. All crew members performed very well.


Second narrative: The flight attendant crew encountered severe turbulence on our initial approach. Many passengers were injured and two aft crewmembers were taken to the hospital when paramedics met the flight. My safety concern is related to policy/procedure in that we did not receive a phone call or PA following the turbulence incident. After being forcibly thrown down into my jumpseat at 1L and securing myself with the harness; I waited for the turbulence event to desist. Before sterile flight operations; I called the flight deck to inquire as to any further reports of turbulence ahead. The captain said he did not expect any and that he was aware of a passenger injury in the aft. I reported that I would assess cabin conditions and keep him informed of the status in the back of the aircraft; which both myself and the Lead Flight Attendant did. We requested medical assistance at the gate upon arrival for both passengers and crew. We landed and medical support immediately boarded to triage and assist injured passengers and crewmembers. I am unsure of what happened to the flight deck because after paramedics boarded; they were gone from the aircraft. We heard nothing from them at all after our phone conversation during initial approach; again; which the flight attendants initiated.


Synopsis: A B737 Captain and Flight Attendant describe an unanticipated encounter with severe turbulence during descent through FL300; causing injuries to passengers and flight attendants.