Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 126
Situational Awareness
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Human Factors
We were cleared via radar vectors off airway to 4;000 feet. IAF altitude was 3800 feet. FO was descending in Level Change from 6;000 feet. Just didn't look right out the window; so I told the FO to come out of Level Change and level off (around 5;000 feet.) I was crosschecking the terrain display and toggling my EFB to the Approach page from the Arrival page. Terrain display showed terrain OK; but still didn't look right. FO descended to approximately 4700 feet when ATC gave us a terrain alert and told us to climb back to 5000 feet. FO stated he was sure that we were given 4000 feet but I responded that I didn't feel comfortable flying into the terrain just because we were cleared to do so.
B737-700 Captain reported becoming uncomfortable during descent on arrival into BUR about the time ATC issued a low altitude alert. No GPWS warning was received.