Date: 201504
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 20
Light: Night
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: Tower ZZZ
Aircraft component: Trailing Edge Flap
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: Descending on an RNAV arrival we were vectored off the arrival given a 310 heading. Visibility was approximately 20 miles. The controller pointed out traffic to follow which we had seen the whole time approximately 7 miles ahead on final to [Runway XY]. FO called traffic in sight and we were given a 270 heading to join final and cleared for the visual to [Runway XY]. We were also told to maintain 180 knots until 5 miles out. The FO extended the final approach course from FAF. The approach checklist was already completed. Looking at my map I noticed we were going to intercept the final approach well inside the FAF. I called for the FO to set 1500 on the MCP (1700 was the FAF altitude). I clicked the autopilot off and armed the approach mode. I also had level change and heading select at 270 set on the MCP. The GS was unreliable at the angle we were approaching and the VASI was not visible yet also. I had been at flaps 1 and 210 as assigned earlier and called for flaps 5 and called to set 190 on the MCP. I was doing some mental calculations of a 3 to 1 descent path. At approximately 8 miles I called gear down; flaps 15; set 180. I noticed as I was approaching final the airspeed was at 180 and the VASI appeared and was showing red over white; on path. I called set 160 (Vm15 on the airspeed bug was 155). I then called for flaps 30. At approximately 1200 AGL the FO said the flaps were indicating 25 and I checked the handle and they were at 25. I told him did he set 30 and he said yes; but they stayed at 25 so he returned the handle to 25. I told him he probably set 30 degrees over the flap placard speed of 175 KIAS. To be honest; I very likely called for flaps 30 at 180 KIAS thinking I was already under 175 KIAS. I waited to slow to about 160 KIAS and called for him to set 30. The flaps did not move; and they stayed at 25. We were now at about 600 AGL. After considering the clear weather; dry runway; and the 8800 feet of available runway on [Runway XY] I decided to continue the approach and landing after concurrence from my FO. Vref30 was recalculated at 146 with a target speed of 152. The calculated stopping distance at flaps 30; auto brakes 3 was approximately 6600 at our weight of approximately 140;000 lbs. I decided to stay at my current speed of 162 KIAS and landed uneventfully. We turned off the runway at the planned taxiway Echo. Once at the gate I had a thorough debrief with my FO and I wrote up the mechanical in the aircraft maintenance logbook.




Synopsis: On final a B737-800 crew realized the trailing edge flaps were apparently not extending below 25; so they increased approach speed and landed without incident.