Date: 201910
Local time of day: 0601-1200
Location: DFW.Tower, TX
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 DFW
ATC / advisory: Tower DFW
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Distraction; Communication Breakdown; Human-Machine Interface
Anomaly: Conflict Airborne Conflict; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We were returning on the second leg of a 4-day trip. This was my first trip with the First Officer who was the Pilot Flying and is relatively new in the aircraft.We were switched to Runway 18R after planning to land on Runway 17C or 17L and were vectored in to a visual approach. Weather was good and not a factor. We both had the field and we were cleared for a visual approach to 18R. I noticed the First Officer going through the extended final and advised him of such and he corrected back after overshooting. He intercepted final and began down on a normal glide slope. At about 1;900 ft.; he had still not lowered the gear so I ask him if he wanted gear. We lowered the gear; but we did not slow enough for final flaps and at 1;000 ft. I directed a go-around.I told Tower we were going around and to the best of my recollection; Tower said to fly runway heading to 2;000 ft. We were just passing 2;000 ft. so I asked Tower if they wanted us to return to 2;000 ft. but they said climb to 3;000 ft. We did so. At some point around then we were switched to approach and either Tower or approach gave us a 210 heading. I set 210 but apparently did not select HDG SEL so the First Officer was getting Flight Director guidance for the published missed approach. I saw we started turning as soon as I entered the heading so believed all was good. As we were cleaning up and leveling off ATC said confirm heading 210 and glancing up at the HDG SEL window and seeing 210 I confirmed 210. As I continued my crosscheck I realized we had passed 210 on the way to 250 for the published missed approach and that I had not selected HDG SEL. I immediately did so after what I would agues was a 20-30 degree overshoot and told the First Officer to come left to 210.At the same time ATC told us to climb to 4;000 ft. which we did. We then received vectors to Runway 13R.While being vectored to final on Runway 13R we were vectored over a VFR aircraft under final and received an RA which caused us to initiate a short climb before clearing the conflict. We were advised of the traffic but never saw it and we were never below our assigned altitude.We reported the RA to ATC and continued our approach.We were switched to Runway 18R after planning to land on Runway 17C or 17L and were vectored in to a visual approach. Weather was good and not a factor. We both had the field and we were cleared for a visual approach to Runway 18R. I noticed the First Officer going through the extended final and advised him of such and he corrected back after overshooting. He intercepted final and began down on a normal glide slope. At about 1;900 ft.; he had still not lowered the gear so I ask him if he wanted gear. We lowered the gear; but we did not slow enough for final flaps and at 1;000 ft. I directed a go-around.I told Tower we were going around and to the best of my recollection; Tower said to fly runway heading to 2;000 ft. We were just passing 2;000 ft so I asked Tower if they wanted us to return to 2;000 ft. but they said climb to 3;000 ft. We did so. At some point around then we were switched to approach and either tower or approach gave us a 210 heading. I set 210 but apparently did not select HDG SEL so the First Officer was getting FD guidance for the published missed approach. I saw we started turning as soon as I entered the heading so believed all was good. As we were cleaning up and leveling off ATC said confirm heading 210 and glancing up at the HDG SEL window and seeing 210 I confirmed 210. As I continued my crosscheck I realized we had passed 210 on the way to 250 for the published MA and that I had not selected HDG SEL. I immediately did so after what I would agues was a 20-30 degree overshoot and told the First Officer to come left to 210.At the same time ATC told us to climb to 4;000 ft. which we did. We then received vectors to Runway 13R.While being vectored to final on Runway 13R we were vectored over a VFR aircraft under final and received an RA which caused us to initiate a short climb before clearing the conflict. We were advised of the traffic but never saw it and we were never below our assigned altitude.We reported the RA to ATC and continued our approach.In my opinion; the major factors were the First Officer's low time in the aircraft; my desire not to be too proactive on corrections not realizing the First Officer's experience level not completing a proper flow for the go around.In retrospect I should have been much more proactive in helping the First Officer fly his visual approach. I made corrections and offered suggestions at times I thought were not too early but also sufficient to fly a safe approach. These were too late and resulted in the go-around.Then by not confirming the appropriate NAV mode; I believe that caused a heading deviation.I did not realize how new the First Officer was in the aircraft until after our first leg. I should have had a conversation with him before our first leg about his experience and comfort in the aircraft and perhaps that would have caused me to be more proactive in my role as Pilot Monitoring which would have prevented the go around in the first place.As far as the go-around; from now on I will verbalize the go-around litany even if I am the Pilot Monitoring to make sure I don't miss anything again.




Synopsis: B737-800 Captain reported that a loss of situational awareness and an inexperienced First Officer resulted in an unstable approach and deviation from the published missed approach.