Enroute controller described a below authorized altitude event when failing to review route filed vs...

Narrative:

I was working an IFR aircraft descending to 11;000. I was also working a VFR aircraft. The VFR was more than 50 miles south of his intended course trying to avoid weather and having difficulty seeing terrain at night. I advised the VFR of weather reported at airports along his route and suggested a safer route. The IFR aircraft inbound advised the VFR to remain south of his destination and proceed west awhile before turning north. At this time tower requested IFR departure for a BE20. I released the BE20 to 12;000 as requested and stopped the inbound at 13;000. The terrain alert volume (tav) in the center had recently been adjusted and I thought the route of flight would work for the new tav [setting] but I would check it when he was airborne. The IFR inbound cancelled his IFR rather than be delayed into the airport. At this time I should have climbed the BE20 to 13;000 which is always safe going to his destination but neglected to do so. The BE20 entered a 12;900 tav at 12;000. I advised the BE20 to maintain 12;000 while in controlled airspace. He answered; 'maintain 13;000 while in controlled airspace.' I decided it was easier to allow him to climb than to correct him. I should have cleared the BE20 short to the VOR than checked the route to make sure it cleared all terrain.

Original NASA ASRS Text

Title: Enroute Controller described a below authorized altitude event when failing to review route filed vs. altitude; listing both weather distractions and low Terrain Alert Volume (TAV) settings as contributing to the event.

Narrative: I was working an IFR aircraft descending to 11;000. I was also working a VFR aircraft. The VFR was more than 50 miles south of his intended course trying to avoid weather and having difficulty seeing terrain at night. I advised the VFR of weather reported at airports along his route and suggested a safer route. The IFR aircraft inbound advised the VFR to remain south of his destination and proceed west awhile before turning north. At this time Tower requested IFR departure for a BE20. I released the BE20 to 12;000 as requested and stopped the inbound at 13;000. The Terrain Alert Volume (TAV) in the Center had recently been adjusted and I thought the route of flight would work for the new TAV [setting] but I would check it when he was airborne. The IFR inbound cancelled his IFR rather than be delayed into the airport. At this time I should have climbed the BE20 to 13;000 which is always safe going to his destination but neglected to do so. The BE20 entered a 12;900 TAV at 12;000. I advised the BE20 to maintain 12;000 while in controlled airspace. He answered; 'Maintain 13;000 while in controlled airspace.' I decided it was easier to allow him to climb than to correct him. I should have cleared the BE20 short to the VOR than checked the route to make sure it cleared all terrain.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	996660
Time
Date	201203
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Make Model Name	Super King Air 200
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Inflight Event / Encounter CFTT / CFIT

Enroute controller described a below authorized altitude event when failing to review route filed vs. Altitude; listing both weather distractions and low terrain alert volume (tav) settings as contributing to the event.