Narrative:

While on approach to ZZZ; the first officer (first officer) was pilot flying (PF) and during the approach the autopilot had difficulty maintaining a stable approach. Both the first officer and I made the determination to override the autopilot and hand fly the remainder of the approach. While doing so; we had a tail wind equal to or greater than 47 kts below 1;000 feet. We continued the approach to roughly 700 feet AGL when we both determined the approach was no longer stable enough to continue to the runway in visual conditions and executed a missed approach. We then got vectors and due to the winds aloft we decided to attempt an approach to [the opposite] runway ZZZ. The first officer requested I fly this approach; which I willingly agreed. I made an announcement to the cabin our intentions to return for a second approach. During this time turbulence increased at 4;000 feet and was constant moderate turbulence. We received vectors to final on [the] runway. As I was flying the approach the autopilot was having trouble maintaining a stable approach. I began to manually fly the approach and we were stable to 500 feet (airspeed was +/- 25-30 kts) and at roughly 400 feet we received a windshear caution and executed a second missed approach. Once we were clear of the wind shear event; we began to clean up the aircraft and at roughly 3;000 feet I engaged the autopilot; however; the autopilot immediately disengaged. I was manually hand flying when we encountered severe turbulence where the aircraft was in a nose up attitude with T/O 1 thrust and we began to descend at roughly 500 ft/min. We began a slow climb and there were brief moments the aircraft was not controllable. ATC gave us an initial climb to 4;000 feet and I asked the first officer to request a higher altitude. We were then given 5;000 feet and I responded that we needed higher and were given 6;000 feet. The turbulence began to subside just above 5;000 feet and we were clear of this event at or around 6;000 feet. I then made the decision to return to [departure airport] due to the possibility of low fuel after executing two missed approaches in ZZZ. We sent dispatch a message via ACARS to advise we were returning to [departure airport]. We landed [at departure airport] without any further incident and I made a call to maintenance to have the aircraft inspected.I was also contacted by the [chief pilot (cp)] to ask if we were 'ok' and was anyone injured on the flight. No injuries were reported and multiple passengers thanked us for coming back to [the departure airport]. Chief pilot asked if I was sure we encountered severe turbulence; and I made known that I am positive we encountered severe turbulence. Cp went on to say that if I read the definition of severe turbulence; I may realize that I did not encounter severe turbulence. After reading in the fom turbulence intensity; I am most certain we definitely encountered severe turbulence.

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Original NASA ASRS Text

Title: B737 Captain reported that the autopilot had difficulty maintaining a stable approach due to turbulence.

Narrative: While on approach to ZZZ; the First Officer (FO) was Pilot Flying (PF) and during the approach the autopilot had difficulty maintaining a stable approach. Both the FO and I made the determination to override the autopilot and hand fly the remainder of the approach. While doing so; we had a tail wind equal to or greater than 47 kts below 1;000 feet. We continued the approach to roughly 700 feet AGL when we both determined the approach was no longer stable enough to continue to the runway in visual conditions and executed a missed approach. We then got vectors and due to the winds aloft we decided to attempt an approach to [the opposite] Runway ZZZ. The FO requested I fly this approach; which I willingly agreed. I made an announcement to the cabin our intentions to return for a second approach. During this time turbulence increased at 4;000 feet and was constant moderate turbulence. We received vectors to final on [the] Runway. As I was flying the approach the autopilot was having trouble maintaining a stable approach. I began to manually fly the approach and we were stable to 500 feet (airspeed was +/- 25-30 kts) and at roughly 400 feet we received a WINDSHEAR CAUTION and executed a second missed approach. Once we were clear of the wind shear event; we began to clean up the aircraft and at roughly 3;000 feet I engaged the autopilot; however; the autopilot immediately disengaged. I was manually hand flying when we encountered severe turbulence where the aircraft was in a nose up attitude with T/O 1 thrust and we began to descend at roughly 500 ft/min. We began a slow climb and there were brief moments the aircraft was not controllable. ATC gave us an initial climb to 4;000 feet and I asked the FO to request a higher altitude. We were then given 5;000 feet and I responded that we needed higher and were given 6;000 feet. The turbulence began to subside just above 5;000 feet and we were clear of this event at or around 6;000 feet. I then made the decision to return to [departure airport] due to the possibility of low fuel after executing two missed approaches in ZZZ. We sent Dispatch a message via ACARS to advise we were returning to [Departure Airport]. We landed [at Departure Airport] without any further incident and I made a call to maintenance to have the aircraft inspected.I was also contacted by the [Chief Pilot (CP)] to ask if we were 'ok' and was anyone injured on the flight. No injuries were reported and multiple passengers thanked us for coming back to [the Departure airport]. Chief Pilot asked if I was sure we encountered severe turbulence; and I made known that I am positive we encountered severe turbulence. CP went on to say that if I read the definition of severe turbulence; I may realize that I did not encounter severe turbulence. After reading in the FOM Turbulence Intensity; I am most certain we definitely encountered severe turbulence.

Data retrieved from NASA's ASRS site 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.