B737-800
Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Human Factors
During the arrival/approach phase into LAX while on an intercept heading to Runway 06R I noticed our altitude was lower than where I wanted to be. We were in VMC conditions and cleared the Visual to runway 06R and about to intercept the LOC and the glideslope from out over the ocean with the autopilot engaged and everything looking normal. I was still configuring and had planned a 30 flap landing and was at flaps 25 when I noticed that we were sinking below glideslope and the autopilot had not captured the glideslope. Since we were out over the water at night there were very few visual indications of our altitude. By the time I noticed it and started a correction; we were a few hundred feet below a 1000 feet. Because of our position on final; we decided to climb up and configure to 30 flaps and intercepted glide slope and were stabilized at 1000 feet. Because we were cleared the visual and able to get back to a stabilized approach at 1000 feet we elected to continue. Once the deviation was noticed; it was decided by both the Captain and me that a go-around wasn't necessary since we were able to be on a stabilized approach at 1000 feet. The night before we had flown the all-nighter/red-eye to BOS and this flight was also a relatively late arrival. The Captain told me that he had also filed an ASAP report.
On a north downwind; LAX tower cleared us to follow traffic that we had in sight for the visual approach to 6R at LAX. First Officer (FO) was pilot flying and was using heading select and vertical speed to intercept final. We began to slow and configure the aircraft. I diverted my attention to adjusting the lighting on my iPad. When I returned heads up in the cockpit; I realized that although we were on course; we were low as verified by red over red VASI. We were below a 1000 feet gear down flaps 25; but still several miles out on final. I instructed the FO to climb to 1000 feet and finish configuring to flaps 30. We continued the approach; intercepted a normal 3 degree glide path (backed up by the ILS) and were stable prior to 500 feet AGL. Landing and taxi to the gate were uneventful.Having the cockpit set up; including iPad settings and lighting prior to commencing the approach is critical. In this situation; it would have allowed me to attend to the higher priority of monitoring the final approach. Using the ILS as a backup for visual approaches is also a good technique in that it provides safe parameters for course; glide path and altitude awareness.
B737-800 flight crew reported descending below charted altitude on night visual approach to LAX.