Y90 controller experienced operational error when descending aircraft below MVA.

Attributes
ACN	696582
Time
Date	200605
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bdl.airport
State Reference	CT
Altitude	msl single value : 3500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : y90.tracon
Operator	common carrier : charter
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller non radar : 3 controller radar : 20 controller time certified in position1 : 17
ASRS Report	696582
Person 2
Affiliation	company : charter
Function	flight crew : captain oversight : pic
Events
Anomaly	non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

B1900 was delivered to me working the bristol radar; hartford rocker and final vector position combined from west departure descending to 5000 ft. I issued B1900 a descent to 3000 ft which B1900 read back correctly. I intended to issue a descent to 4000 ft; the MVA in the area. I observed B1900 at 3700 ft approximately 2 mi from the 4000 ft and 2500 ft MVA border headed into the 2500 ft MVA. I issued B1900 a clearance to maintain 4000 ft. B1900 said he was given a clearance to maintain 3000 ft. I again issued B1900 4000 ft and he climbed back to 4000 ft. No MSAW alarm was activated.

Original NASA ASRS Text

Title: Y90 CTLR EXPERIENCED OPERROR WHEN DSNDING ACFT BELOW MVA.

Narrative: B1900 WAS DELIVERED TO ME WORKING THE BRISTOL RADAR; HARTFORD ROCKER AND FINAL VECTOR POS COMBINED FROM W DEP DSNDING TO 5000 FT. I ISSUED B1900 A DSCNT TO 3000 FT WHICH B1900 READ BACK CORRECTLY. I INTENDED TO ISSUE A DSCNT TO 4000 FT; THE MVA IN THE AREA. I OBSERVED B1900 AT 3700 FT APPROX 2 MI FROM THE 4000 FT AND 2500 FT MVA BORDER HEADED INTO THE 2500 FT MVA. I ISSUED B1900 A CLRNC TO MAINTAIN 4000 FT. B1900 SAID HE WAS GIVEN A CLRNC TO MAINTAIN 3000 FT. I AGAIN ISSUED B1900 4000 FT AND HE CLBED BACK TO 4000 FT. NO MSAW ALARM WAS ACTIVATED.

Data retrieved from NASA's ASRS site as of January 2009 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.