Date: 201508
Location: MDW.Airport, IL
Flight conditions: Mixed
Weather elements / visibility: Thunderstorm; Turbulence; Windshear
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C MDW
ATC / advisory: TRACON C90
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Human factors: Workload; Time Pressure; Situational Awareness; Distraction; Communication Breakdown
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control; Flight Crew Diverted
Contributing factors: Company Policy; Procedure; Weather
Primary problem: Weather

Narrative: This is the second time in so many months that I have been on hold by Dispatch for a weather forecast; but it seems that the weather center is not keeping up with real time conditions. We departed for MDW an hour late; due to MDW forecast for T-Storms and frontal passage. About 15 minutes from landing; the front was about 15 miles away to the north. We were being vectored onto RWY 22L on a NW HDG. ATC put a Company jet between us and another Company approximately 10 miles ahead. To get spacing; they gave us direct STERE (a northerly HDG) and clearance for the approach. Storms were still N of our position and N of STERE by about 7 and 4 miles respectfully.Within about 30 seconds; we started experiencing moderate turbulence and windshear. I told the FO to turn and told ATC we needed a turn. It was granted. In the turn away from weather; we got severe turbulence; to include violent abrupt yaw moments; airspeed flux of 30-40 knots; and bank angles in excess of 45 degrees. ATC gave us an airspeed of 210 or less. I said 'unable.' We had altitude deviation of 500 feet. We escaped to the SW and paralleled the approach course.After it smoothed out; we attempted to reacquire the approach course just south of downtown Chicago. We experienced a very strong updraft. Concerned it would be followed by a downdraft and well above glidepath; we went around to the south. ATC gave us vectors to a visual downwind for another attempt. After switching to Tower; and on base; Tower reported a windshear alert of 35 knots on final. We decided to go around since we were again experiencing large wind shifts. We diverted to our alternate.What disappointed me also was the lack of credibility our pilots in following aircraft put in our report. Two airplanes behind us continued on a similar path; we were just a minute or two before them. They also experienced severe turbulence. After hearing that behind us; I told Chicago Approach; that no other planes should be allowed to fly through that.It was the worst turbulence I had experienced in my flying experience of [over two decades]. Aircraft control was lost for certain periods of time and our other pilots decided it was okay to fly into that. We obviously were not able to maintain our assigned clearance due to the turbulence. We were unable to maintain the assigned course; altitude; or airspeed. The weather center needs to real-time update weather holds for current radar conditions to not place jets in greater danger. Our pilots need to listen up and wise up; and trust Company Pilot reports.




Synopsis: An air carrier on approach to MDW encountered severe turbulence with momentary losses of control. Unable to completely avoid the weather and with windshear warnings at MDW; the flight diverted to its alternate.