B737 captain reported unsafe condition resulted from ATC climb clearance issued as flight crew was r...

Attributes
ACN	1556815
Time
Date	201807
Local Time Of Day	0601-1200
Place
Locale Reference	NCT.TRACON
State Reference	CA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 822
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance Inflight Event / Encounter CFTT / CFIT

Narrative:

ATC assigned us to maintain 210 kts while vectoring us to intercept the runway 28R localizer and a descent to 3;000 feet followed by a clearance for the approach in VMC and to maintain 180 kts until 5 miles out. I asked the first officer (first officer) to set 1;800 feet in the MCP (mode control panel) altitude window; pushed the approach button and verified FMA's (flight mode annunciator) to be correct with single channel displayed while configuring the jet. The autopilot pushed the nose over while tracking the localizer and quickly descended below 1;500 feet. The ATC controller called out a low altitude warning approaching axmul. I disconnected the autopilot and started to climb towards 1;800 feet. The ATC controller issued a climb to 3;000 feet which confused us because we were not sure if he meant go-around. I commanded a go-around and executed the procedure while climbing to 3;000 feet in order to repair the unsafe condition and confusion over the perceived non-standard phraseology.

Original NASA ASRS Text

Title: B737 Captain reported unsafe condition resulted from ATC climb clearance issued as flight crew was responding to to a previously issued low altitude alert.

Narrative: ATC assigned us to maintain 210 kts while vectoring us to intercept the Runway 28R Localizer and a descent to 3;000 feet followed by a clearance for the approach in VMC and to maintain 180 kts until 5 miles out. I asked the FO (First Officer) to set 1;800 feet in the MCP (Mode Control Panel) altitude window; pushed the approach button and verified FMA's (Flight Mode Annunciator) to be correct with Single Channel displayed while configuring the jet. The autopilot pushed the nose over while tracking the localizer and quickly descended below 1;500 feet. The ATC controller called out a low altitude warning approaching AXMUL. I disconnected the autopilot and started to climb towards 1;800 feet. The ATC controller issued a climb to 3;000 feet which confused us because we were not sure if he meant go-around. I commanded a go-around and executed the procedure while climbing to 3;000 feet in order to repair the unsafe condition and confusion over the perceived non-standard phraseology.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B737 captain reported unsafe condition resulted from ATC climb clearance issued as flight crew was responding to to a previously issued low altitude alert.