Date: 201901
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 5
Light: Daylight
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Final Approach
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Fatigue; Communication Breakdown
Second reporter function: First Officer; Pilot Flying
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Environment - Non Weather Related; Human Factors; Equipment / Tooling
Primary problem: Human Factors

Narrative: Prior to arriving for duty; I attempted to take a nap in the evening. I slept for a couple of hours; but could not sleep more than that. I felt fine when arriving for duty. I was coming off of [several] days off. I was the pilot monitoring and the First Officer was the pilot flying. Weather was extremely clear and daylight. Light tailwind at altitude. Very light airplane with 10K fuel and empty cans. We were both extremely tired; and communication was degraded between us due to a loud cockpit and mixed headset use (I was using an ANR headset and the FO (First Officer) was using [an ear plug style headset] with the left plug out of his ear so he could hear me). As it turns out; this is not a good CRM setup and communication was compromised between us. I didn't realized the FO was struggling to hear me throughout the flight until we discussed it on the ground.ATC kept us very high before clearing a descent to intercept the ILS XXL about 5 miles from ZZZ. I mentioned to the First Officer that it was going to be difficult to shoot the approach due to this. We were slightly high and fast just outside ZZZ and I suggested we needed to drop the gear and slow down to get stabilized. We were still 10 to 15 knots fast as we approached ZZZZZ; but on glideslope and it looked like we would be on speed at 500 AGL. I suggested we may need to do a go-around. I thought the FO acknowledged; but after the fact he told me he wasn't sure if I was commanding a go-around and was thinking I was waiting to see the results of a continued approach. On our previous leg we discussed going around and the shared belief that a go-around at altitude should be a slow paced methodical event. The autopilot should be engaged and both crewmembers on the same page. I honestly thought that's where we were headed. I made a mistake at that time by not being very specific and commanding a go around. We were on speed and stable at 500 AGL and it was a normal landing. However; I felt we were at the limits of FOM compliance and I don't like to be in that situation.We talked about it in the parking lot and we both realized we were very tired and the FO felt he was behind. We both decided if we could do it again we should have executed a go-around to eliminate any potential for problems. Being kept high in a light airplane is always a challenge; but add fatigue and degraded CRM due to communication difficulties to the mix and the task saturation is very high. As a suggestion; it would be extremely helpful if [we] had hot mics. The enhancement to communication would be a dramatic improvement and a real safety addition.


Second narrative: The flight in question was the return leg to ZZZ that departed [early morning.] I was off for several days prior to this flight and got a 2 hour nap before going to work for the first leg. Initially; I felt well rested and ready to fly. That changed significantly on the second leg. By the top of descent; I was feeling very tired. On this leg I was the pilot flying and the Captain was pilot monitoring. We have flown together before and work well together from my perspective. We were arriving on the Arrival and approaching ZZZZZ we were still being held at 8000 feet. The CA (Captain) requested lower and we were finally cleared to descend to 4000 feet and cleared for the approach. Immediately the CA commented that it would be a challenge to get down; slowed up and configured in time. I heard the comment but did not respond to it or fully appreciate that he was really pointing out that we were already behind. I still felt fine. I recognize now that I was really tired and just not reacting as quickly as I normally would have. Once on the localizer I hit the appr button but it was a little too late and the aircraft failed to capture the glide slope. I initially hit the V/S button to regain the glideslope and then immediately realized we did not have enough time for that so I disconnected the autopilot. At that point I heard the CA say something about the gear but to be honest I was having a difficult time hearing him. He was wearing an ANR headset and talking a little soft. I struggled with it the whole flight but he did not know it because I failed to tell him. That was a CRM breakdown on my part. We got the gear down and started working the flaps and the aircraft began to slow rapidly. I heard the CA mention the approach was not looking good and I was preparing myself mentally to execute a go around. As we passed through 1000 feet I do not recall what the parameters were but we did managed to get stabilized by 500 feet and make a normal landing on speed in the touchdown zone. However; this approach never should have continued. Recognizing I was not fully stable and my situational awareness was deteriorating I should have executed the go-around procedure long before I ever got to the 1000 foot call. In the future if I find myself in a similar situation I will communicate more effectively with the CA and execute the go around early in order to slow things down and start again. Secondary causal factors in this event were my fatigue and a breakdown of communication between myself and the CA. Both of those factors could have been mitigated by better CRM on my part. I should have let the CA know how tired I was feeling and that I was having difficulty hearing him. Going forward I will take those lessons with me as well.


Synopsis: B757 flight crew reported communication breakdown between Captain and First Officer and degraded CRM during approach.