A TRACON controller reported assigning an aircraft an altitude below the minimum vectoring altitude.

Attributes
ACN	1508868
Time
Date	201801
Local Time Of Day	0601-1200
Place
Locale Reference	NCT.TRACON
State Reference	CA
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Visual Approach Vectors
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 1
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

I was vectoring the aircraft for a visual approach and he was descending to 3000. The aircraft was heading for a minimum vectoring altitude (MVA) of 3900. When the aircraft was at 4200 feet; I initiated a turn away from the MVA. The aircraft was slower to turn than anticipated. I asked the pilot if he had the terrain in sight. The pilot stated that he did. I instructed him to maintain terrain and obstruction clearance and turned him further away from the MVA before he descended into it. My supervisor told me I could not do that. My supervisor instructed me to file this report. While I was in training; my instructors taught me that instructing the pilot to maintain his own terrain and obstruction clearance before he was below the MVA was correct.

Original NASA ASRS Text

Title: A TRACON Controller reported assigning an aircraft an altitude below the Minimum Vectoring Altitude.

Narrative: I was vectoring the Aircraft for a visual approach and he was descending to 3000. The Aircraft was heading for a Minimum Vectoring Altitude (MVA) of 3900. When the Aircraft was at 4200 feet; I initiated a turn away from the MVA. The Aircraft was slower to turn than anticipated. I asked the pilot if he had the terrain in sight. The pilot stated that he did. I instructed him to maintain terrain and obstruction clearance and turned him further away from the MVA before he descended into it. My supervisor told me I could not do that. My supervisor instructed me to file this report. While I was in training; my instructors taught me that instructing the pilot to maintain his own terrain and obstruction clearance before he was below the MVA was correct.

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.