Date: 201508
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Flight conditions: IMC
Weather elements / visibility: Thunderstorm; Turbulence
Light: Night
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Weather; Procedure
Primary problem: Weather

Narrative: We were on the downwind at 7000 ft descending to 4000 ft (I think) when we were vectored into severe thunderstorm cells. We were assigned a speed of 170 and had flaps 20 selected. Once inside the thunderstorm we encountered severe wind shear with lightning all around us (don't know if we were hit). The airspeed must have fluctuated almost a 100 kts and we went several times from stick shaker into overspeed by about 20 +/- with bank angle up to 40-45 degrees while in a turn on autopilot out of the thunderstorm cell. We could not maintain the assigned speed due to the severe wind shear airspeed fluctuations. Several times we had to advance full pwr (Power) to keep the speed out of the stick shaker. We did not want to do a wind shear escape maneuver to avoid flying deeper into the cell. We could see the clear area ahead of us on the nav (Navigation) display hence we decided to keep turning and after 10 to 20 seconds we were out of it. We wrote up the overspeed (10-20kts) for the selected flap setting of 20 degrees and possible lightning strikes.We asked the Controller to give us a right turn in less than 2 miles but she turned us just about a mile or 2 too late. Approach in the clear and landing were uneventful.  The flight in front of us must have encountered similar weather and told ATC not to let anybody go as far on the downwind. ATC should have had more spacing between flights to allow a turn short of the thunderstorm cell.


Second narrative: Aircraft on downwind; approaching weather front from the west and north. Several aircraft in front of us on downwind reported severe turbulence on base leg; we requested a turn in 2 miles or less; with weather on both sides of us; we had few options. Upon being given 170 knots; and a descent to 4000 from 5000; we initiated a base turn; upon entering a strong cell; the aircraft encountered a severe drop in altitude; followed immediately by an updraft; severe airspeed fluctuations going from stick shaker to overspeed were instantaneous. Aircraft went to approx 40 deg of bank. Throttles were overridden in order to not chase airspeed; executing a wind shear maneuver per se would have exacerbated the situation; as we need to continue our turn to escape the cell. Airspeed exceeded the flaps 20 limitation by approximately 10-20 knots. Aircraft flew out of the cell; continued the approach visually; with no further discrepancies. Encroaching weather system; and the lack of ATC foreseeing the need to close off the downwind. Better ATC flow control with given weather conditions. They were extending the downwind into the weather; by allowing several aircraft requesting close in base turn; and approving their request. Several crews advised ATC to not let any aircraft go where they had been. Too late for us unfortunately.


Synopsis: B767-300 flight crew reports being vectored into a thunderstorm during approach after requesting that the storm be avoided. Previous aircraft had reported severe turbulence and this crew reported stick shaker and flap overspeed along with bank angles to 40 degrees before exiting.