B767-300 and 300 ER
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human-Machine Interface; Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented
Human Factors
During the descent to MROC I thought we were too high; I notice I had entered 16;000 feet instead of 160 knots in the FMC. I asked the First Officer (FO) what is the charted crossing altitude he said 8;000 feet. I know at that point there was no way we could continue the approach. Gear was down; Flaps 30 and on the LOC. I told the FO to tell the Tower that we want to orbit 360 (RH Turn) at ZZZZZ (8000 feet) because we were too high. No immediate reply from the Tower; so I began the RH turn. FO joined me on TAWS and we were cleared to join the approach and report on the loc. We then flew direct to ZZZZZ and the approach was normal. The weather was IMC we descended below the minimum radar vectoring altitude prior to joining the LOC. I accept responsibility for the decision to turn and should have continued straight ahead and ask for radar vectors to for another ILS approach. We were under no time pressure as we had more than enough fuel. The problems with automation was triggered by the intended 160 knot entry triggered 16;000 foot crossing instead. Check and recheck the FMC; and get FO to check for errors. Brief a plan of action in case too high. Tell ATC we are too high; request radar victors to rejoin the approach.
B767 Captain reported flight crew failed to properly load the FMS. While rejoining the final approach course the crew descended below the minimum vectoring altitude.