Date: 201701
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Trailing Edge Flap
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Executed Go Around / Missed Approach; Flight Crew Became Reoriented
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: 15 Flaps landing using Trailing Edge Flap Disagree checklist. We were unable to select Trailing Edge Flaps so I initiated a go-around from final.We were held at 10;500 ft and speed 210 because of opposite general aviation traffic close to our position and altitude. ATC was trying to talk our eyes onto the traffic. Once we had visual acquisition and passed the traffic; we were cleared to a couple of step down altitudes.  Then we were cleared for the Visual. Called for Flaps 1 with speed brake out at about 9000 ft speed 210. I could feel the additional drag so ops normal. My nav display went blank.  This was in the book and a recurring write up and had something to do with lack of a software update.  We were visual so no problem. I expanded my crosscheck to First officers (FO) Nav Display. (The inbound crew said both displays go blank when opposite source selected). We were turned to a North West heading. Speed brake retracted and called for Flaps 5. Cleared visual approach. Called for [landing] gear going thru about 3500 ft. Held off of Flaps 15 because we were right at 200 KIAS. As the speed bled off slowly and tracking the glideslope; called for Flaps 15 at about 192 KIAS. The aircraft was very slow in speed reduction. Ready to call for Flaps 25 and speed about 170; I noticed the Minimum Maneuver Speed (Amber) was about 159 KIAS and was above the Flaps 15 bug. Clearly something was wrong and looked over at the Flap Position Indicator. It showed Flaps 0.  Initiated a go-around. I disconnected autopilot and hand flew for better feel. My First Officer transitioned to the Angle of Attack (AOA) gauge and verbalized that we were safely above the green mark. We climbed to 3000 ft; turned west. We climbed to 5000 ft and proceeded with Trailing Edge Flap Disagree checklist. We then completed the Emergency Landing checklist. We requested and landed on the longest runway. Normal touchdown to full stop and cleared the runway. No other issues so we taxied to the gate with safety vehicles following behind. Once at the gate; we got an additional wing walker to stand at the fuel cart because our flaps were still down. Parked normally at the gate and deplaned via jet bridge. The aircraft was on auto pilot throughout the descent until the go around was initiated. I disconnected auto pilot to hand fly the missed approach. Once level at altitude; autopilot back on. Hand flew final turn and final to touchdown.Considerations:  1. You might not always see Flaps 1 in the 10 o'clock position but I can use peripheral vision to see Flaps 5 at the 1 o'clock position.  2. We were VFR but; if this would have happened in bad weather with normal divert fuel it could be tight.3. Had one experienced Flight Attendant (FA) and three new FAs. The new FAs were not real clear about [procedures]. They had it in training but not very emphasized. This is what the number one shared with me at the gate. Might need more emphasis on this with newer crews. But they did a great job!


Second narrative: I don't normally check the flap gauge until confirming the final flap configuration. Going forward; I will incorporate a quick confirmation that the flap gauge matches the flap lever position for intermediate as well as final flap settings.


Synopsis: B737-800 flight crew reported executing a go-around after the trailing edge flaps failed to extend on command.