B737 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 156.85; Flight Crew Total 4543.05; Flight Crew Type 4543.05
Troubleshooting; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Aircraft Equipment Problem Dissipated; Flight Crew Executed Go Around / Missed Approach; Flight Crew Overcame Equipment Problem
Aircraft; Human Factors
Descending into ZZZ and planning a normal Flaps landing; speeds 147/142. I was the Flying Pilot and we were asked to slow from 230 to 170. I called for flaps 5 from 1 and then flaps 10. Speed was too great for flaps 10 so changed it to flaps 5. Right after that; intercepted the glideslope and called for gear down; flaps 15; and then flaps 30 and the landing check. As he was doing the Landing Checklist; First Officer pointed out that we had a green light; but flaps were indicating 5. I verified this and though the airplane was handling like it was in final landing configuration; I checked the overhead and it showed leading edge devices were in the intermediate position. Not being able to verify which was true; called for a go around at 1;200 feet AGL and told Tower. Normal go around was accomplished and flaps retracted normally. As we flew the heading and altitude; discussed what we would do if flaps didn't come down. We discussed getting flaps to 10 early to make sure it wasn't a system issue; and everything worked and we accomplished a normal landing. QRH was looked at on the ground; trailing edge flaps disagree was followed with the go around; and with what was going on felt best option was to go around and start again.
[Report narrative contained no additional information.]
B737 flight crew reported a flap extension error on approach leading to a go around.