Date: 201911
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Situational Awareness; Human-Machine Interface; Workload; Time Pressure
Anomaly: ATC Issue All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: On approach to ZZZ we were told to expect ILS 12. Abeam the field at 5;000-6;000 ft. we were told to expect the RNAV XXR approach. I was the pilot flying and my First Officer was flying. I remarked that we had no one in front of us and could be 'slam dunked'. Abeam the Final Approach Fix; we were turned base and descended to 3;000 ft. We received no calls after that and we were high and on base just barely outside the FAF. The First Officer said he had the field visual. I realized we were about to cross final without a vector or a descent. I requested lower and told ATC that we were visual with the field. Approach cleared us to 1;500 ft.; cleared us for the visual approach and sent us over to Tower frequency. The First Officer did an excellent job realizing we were going through final so he switched off the autopilot and turned toward final as we were shooting across final for both Runway XXL and XXR. He corrected back to final but due to the short final; the descent; and the overshooting vectors we were extremely busy and couldn't engage LNAV or VNAV fast enough to catch the course or glide slope. I asked the First Officer is he was okay with flying a 'true visual approach with no guidance'. The weather was good; he had the field visually; and he said 'yes'. The First Officer hurried to configure and I rushed to finish the checklist. As I was 'heads-down' the First Officer was correcting to final course. Due to the fact that we were not in any approach mode (ILS or LNAV/VNAV) the auto-throttles were not working. We got low and slow on final. I stated to the First Officer that we were low and slow and that the auto throttles 'weren't working'; meaning that they were appropriately not doing anything to aid the First Officer. I don't know if I made this statement clearly to the First Officer and should have been very specific that they were completely inoperative in this situation. By the time he realized they were not helping him and that he had to manually operate the throttles; we were low and slow. We were stabilized around 700 ft. after leveling off and correcting but we had been approximately 10 kts. below bug speed (5 below threshold) and all red lights on the PAPI's (Precision Approach Path Indicator). He corrected back to speed and glide path and made an excellent landing.The event occurred due to several reasons. ATC 'slam dunked' us into ZZZ. We were very high; very tight to final; and were turned base abeam the FAF after having our approach and runway changed at the last minute. Approach also failed to turn us to a dogleg or to final and shot us across final. We were rushed and didn't have time to set up the LNAV/VNAV backup to the glide path which would have also given us autothrottles (there is no ILS to this runway for backup). Both the First Officer and myself are new to the airplane and our seats and we were slow to set up the LNAV/VNAV so that it could back us up. The ultimate reason is that when we were given poor guidance by ATC; I did not ask for longer vectors; nor did I direct a go around on final. It is the Captain's fault (mine).Although we received very poor handling from ATC; I could have easily avoided this situation by requesting longer vectors to set up for the RNAV approach to Runway XXL. We had been cleared for the ILS Runway XY and were changed to Runway XXL at the last minute and then slam dunked. If we had requested extended vectors it would have given us time to set up for the approach better. I know better than to let ATC fly my plane. Once we were on final and got destabilized; I should have called a go-around. Instead I opted to call out corrections to the First Officer. He had done an excellent job on the trip and I felt he could fix the situation. He did correct and did an excellent landing but there is no doubt in my mind that we should have gone around and started from scratch. Definitely several lessons learned from this.




Synopsis: B737 Captain reported that a last minute runway change from ATC resulted in an unstabilized approach.