Date: 201808
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Aircraft component: Trailing Edge Flap
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Workload
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Conflict Ground Conflict; Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Executed Go Around / Missed Approach; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: We were on a visual approach. The Approach Controller had kept us high; so it was going to be a rather quick configuration sequence to ensure a stable approach. As we ran the Before Landing Checklist we observed that the flaps had only extended to 2. The Captain initiated a go-around and we informed ATC of the issue; and requested a long downwind to run through the appropriate procedures. We requested that we have a clear runway as we wanted to avoid any more go-arounds. We then ran the QRH procedure for Flap Disagree; which eventually directed us to use alternate flap extension. During the extension; the flaps failed around 5 instead of going to the desired 15. We updated the landing data accordingly and commenced the approach.Somewhere along the way (as we were on a short final) I saw an aircraft in the touchdown zone. I confirmed this with the Tower Controller and he informed me that the aircraft was in the air and was going to sidestep. As we neared the runway it became evident that the aircraft was in the air and we were able to land without further incident.With that said; it seems like there was a significant ATC error that may have compromised safety. It was an odd choice to issue a takeoff clearance directly in front of an aircraft [requiring priority handling]; especially when 2 other runways were available. Furthermore; it was a light single engine aircraft; so his low takeoff and climb speed combined with our faster than normal approach speed resulted in a rapid closure rate. In the event of a go-around we would have lost sight of him; and we would likely have posed a significant wake turbulence hazard for him at a very low altitude. Finally; I do not recall the normal advisory from ATC that there would be a departure prior to our arrival; which would have at least given us time to consider the situation and modify plans.As Pilot Monitoring I could have done a better job with the monitoring part. Things were moving pretty quickly during the landing configuration process and I did not adequately monitor to ensure that the flap handle and indicated flap position were in agreement. It was a breakdown that should have been caught prior to the checklist. It would not have changed the outcome; but would have provided a better safety margin. ATC should not use a runway when an aircraft [requiring priority handling] is on the approach. The reasons stated in the narrative offer a good reason. Furthermore; task saturation for the crew with the malfunctioning aircraft may cause degraded situational awareness; so it is best not to have additional distractions. If ATC did give a traffic advisory; for example; we did not hear it. So from a human factors stand point; it might be best to assume that the crew is operating in the yellow.




Synopsis: B737-700 First Officer reported a trailing edge flap issue and poor handling of landing priority by ATC.