Medium Large Transport
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 141; Flight Crew Total 8000; Flight Crew Type 2000
Distraction; Situational Awareness; Workload
ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Airport; Human Factors; Procedure
VNAV and LNAV did not engage at the transition resulting in being high at the transition. ATC gave us a vector for a visual approach; but no descent clearance. Auto pilot disconnects causing a distraction.We were now trying to descend get to a proper flight path; rearm the approach and prepare to land. My visual perspective appeared to be high on final due to the airport physical features.We were issued a low level altitude alert by the Tower. We leveled caught the VASI and we were configured and stable well above a 1;000 feet MSL.We landed safely and taxied to the gate.I feel a late notice from ATC indicating what transition was being used caused us to be in a hurry to select it in the FMC. We must have had a disconnect in our arrival but now had to turn the aircraft in a hurry. The auto pilot disconnect added confusion; then we needed to descend rapidly in order to get back to profile and configure for landing.It was an unfamiliar arrival added to an unfamiliar approach coupled by things not falling into the usual sequence. Earlier ATC clearances would have allowed more time to properly verify the FMC.
In the process of trying to correct to the proper flight path on an approach; the flight crew was issued a low altitude alert by air traffic control. After taking corrective action and stabilizing the approach; a safe landing was accomplished.