Date: 201412
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Weather elements / visibility: Turbulence; Windshear
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Landing
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Time Pressure; Workload
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; General Declared Emergency
Contributing factors: Aircraft; Weather; Human Factors
Primary problem: Aircraft

Narrative: Vector to visual approach into ZZZ Rwy 16. Front passing through the Sound at our approximate arrival time. LLWS and moderate turbulence forecast. Flight Attendants and passengers seated at TOD. Moderate turbulence encountered from FL 360 down to FL 200; continuous light; occasional moderate thereafter. ZZZ tower wind reported at 150/28G45. During brief for the approach talked with First Officer about his ability and willingness to fly the approach; the absence of LLWS system at ZZZ and a go-around in the event of a windshear warning. The performance data supported landing Rwy 16 F30; max auto brakes; LTP 2200 ft; landing weight of 135k. On final from 3500 ft down to 1000 ft continuous moderate turbulence. At 1000 ft msl windshear warning illuminated and annunciated. Go-around initiated. Encountered moderate to severe turbulence with large airspeed fluctuations +/- 25 knots. During go-around flaps blew back from 15 to 10 with both flap setting placards speeds exceeded. An extremely difficult go-around with the First Officer doing a good job of flying the jet and interpreting the PFD information. Leveled off at 3500 msl; gave Pirep to Arrival and received wind report from ZZZ of 150/21G43; putting the gust out of limits for our operations. Contacted dispatch and was informed that our alternate was holding for arrivals and had multiple aircraft go-around for windshear events. PIC and dispatcher agreed on ZZZ2 as the new destination. Dispatch gave a fuel burn of 3.4 at FL200. We had 8.0 after the go-around. Coordinated a new clearance with Approach to ZZZ2 and briefed the flight attendants and passengers on our new destination. As we were turning south towards our alternate and climbing noticed the flaps indicating F2 plus symmetrical with the flap handle in the up position. Due to leading edge devices in the extend position; and the trailing edge flaps extended determined that we did not have enough fuel nor accurate fuel burn information to continue to ZZZ2. We were at FL190 at 250 knots with a 100 plus knot headwind component. Fuel burn was indicating approximately 7000 lbs per hour with 39 mins enroute to ZZZ2. I already had [advised] ATC Center of the flight control malfunction and informed ATC Center and dispatch that our privious alternate would be our new destination. At that point we were abeam the airport at FL190; 170 knot ground speed with 6.2 fuel remaining. Informed the flight attendants of our new destination and asked them to brief the passengers. Ran the QRH for trailing edge flap disagree and using the alternate flap extension was able to extent the flaps to F15. Completed all the briefings; received landing data from dispatch and transferred controls as I would fly the approach and landing to Rwy 16L. On final had the first officer run the QRH low fuel checklist as fuel was now at 4.1. On final coordinated with tower that in the event of a go-around we would stay on their frequency and in the traffic pattern at 1500 ft and not return to approach. Landed uneventfully on Rwy 16L; exited the runway; stopped and had CFR check the brakes for overheating. Had the first officer coordinate with CFR while I spoke with both the flight attendants and passengers regarding our landing and the CFR equipment they could see around our aircraft. Cleared to continue by CFR and taxied to our gate. Once again split up the duties with the first officer going down to the ramp to interface with the CFR; while I spoke to all the de-planing passengers. We blocked in with 3.3 fuel remaining.In hindsight this was a very difficult series of cascading events starting with the windshear go-around at ZZZ; the initial divert to ZZZ2; the flap malfunction; the second divert to our alternate; and finally the low fuel state becoming critical and compressing the time for the decision making process and checklist execution; all while dealing with moderate turbulence. We were able to split up most of our duties with my first officer flying withthe autopilot engaged and coordinating with ATC; while I dealt with dispatch; ATC; the flight attendants and of course our passengers. It was a very difficult night once we arrived in the area. We made mistakes; but were able to trap and mitigate most of them. The one thing I would have done differently was immediately accomplish the After Takeoff checklist because I would have caught the flap malfunction earlier and diverted to our alternate which would have allowed more time and fuel. I know why I didn't as I was immediately trying to come up with a plan once ZZZ was ruled out. I thought the initial decision to divert to ZZZ2 was good because of the traffic at our alternate and windshear go-arounds that had occurred. Had I also known the go-around at ZZZ was going to be so difficult; I would have flown the approach.




Synopsis: B737-800 Captain reported safely landing after a challenging sequence of events that included multiple diverts for windshear and trailing edge flap issues.