Tys TRACON controller reported their trainee vectored an aircraft below the minimum vectoring altitu...

Attributes
ACN	1539797
Time
Date	201805
Local Time Of Day	1201-1800
Place
Locale Reference	TYS.TRACON
State Reference	TN
Aircraft 1
Make Model Name	Cessna Citation Sovereign (C680)
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach Instructor
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 10.0
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

I was conducting training. A citation was going into gkt airport. They came to us from center at a very high altitude. The developmental's plan was to allow the aircraft to fly to gkt and turn them back on a downwind. The developmental descended the aircraft to 5;000 feet which was fine if they would have vectored them when they were supposed to. As this developed the trainee failed to turn the aircraft at the appropriate time. I tried to take over and vector the aircraft prior to it entering a 6200 foot MVA(minimum vectoring altitude) at 5;500 feet. I also issued a low altitude alert but the aircraft barely entered the higher MVA for about a mile before turning to the north to avoid obstructions and terrain. I should have taken control and turned the aircraft about 20 seconds sooner.

Original NASA ASRS Text

Title: TYS TRACON Controller reported their trainee vectored an aircraft below the Minimum Vectoring Altitude.

Narrative: I was conducting training. A Citation was going into GKT airport. They came to us from Center at a very high altitude. The developmental's plan was to allow the aircraft to fly to GKT and turn them back on a downwind. The developmental descended the aircraft to 5;000 feet which was fine if they would have vectored them when they were supposed to. As this developed the trainee failed to turn the aircraft at the appropriate time. I tried to take over and vector the aircraft prior to it entering a 6200 foot MVA(Minimum Vectoring Altitude) at 5;500 feet. I also issued a low altitude alert but the aircraft barely entered the higher MVA for about a mile before turning to the north to avoid obstructions and terrain. I should have taken control and turned the aircraft about 20 seconds 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.

Tys TRACON controller reported their trainee vectored an aircraft below the minimum vectoring altitude.