Fat TRACON controllers reported an aircraft descended below the published altitude and triggered a l...

Attributes
ACN	1517415
Time
Date	201802
Local Time Of Day	1801-2400
Place
Locale Reference	FAT.TRACON
State Reference	CA
Environment
Light	Dusk
Aircraft 1
Make Model Name	Light Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 5
Person 2
Function	Approach
Qualification	Air Traffic Control Developmental
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

The aircraft was cleared on the ILS Y for runway 29R. The aircraft began the approach. The aircraft began descending below the MVA but still within approach altitudes. The 'low altitude alert' alarmed and the trainee issued a low altitude alert. The aircraft was still descending. I over keyed and told the aircraft to climb. I allowed the trainee to let the process go too far and should have stepped in quicker. I thought the trainee was at a point in the training to allow them to catch mistakes or aircraft mistakes. I should have over keyed quicker and instructed the aircraft to climb sooner.

Original NASA ASRS Text

Title: FAT TRACON controllers reported an aircraft descended below the published altitude and triggered a low altitude alert.

Narrative: The aircraft was cleared on the ILS Y for runway 29R. The aircraft began the approach. The aircraft began descending below the MVA but still within approach altitudes. The 'Low Altitude Alert' alarmed and the trainee issued a Low Altitude Alert. The aircraft was still descending. I over keyed and told the aircraft to climb. I allowed the trainee to let the process go too far and should have stepped in quicker. I thought the trainee was at a point in the training to allow them to catch mistakes or aircraft mistakes. I should have over keyed quicker and instructed the aircraft to climb sooner.

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.

Fat TRACON controllers reported an aircraft descended below the published altitude and triggered a low altitude alert.