Air carrier X GPWS descent below MVA. System error. Evasive action taken.

Attributes
ACN	294917
Time
Date	199501
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : cho
State Reference	VA
Altitude	msl bound lower : 4500 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc tower : cho
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	cruise other descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 1510 flight time type : 200
ASRS Report	294917
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X traveling from pit to cho for air carrier X, I was the PNF operating the radios. We were with ZDC who was starting our descent. He first took us from our cruising altitude to 8000 ft or 9000 ft MSL. We were then told to report the airport in sight and descend to 5000 ft MSL. About 3 or 4 mins, I asked ZDC if the airport was at our 12 O'clock and 12 mi. He told us that it was the airport, so we called it in sight. He then instructed us to descend and maintain 3100 ft MSL, but not to go below that altitude until we contacted tower. We switched frequencys to tower and started our descent to 3100 ft MSL. We called tower and reported our position at about 4500 ft MSL. GPWS went off saying 'too low, pull up.' we stopped our descent and looked at the radar altitude which read 1200 ft. We called tower and asked the altitude of the highest obstacle. He told us the highest point was 3600 ft MSL. We remained at 4500 ft MSL until we got closer to the airport and then landed using the visual stop indicators.

Original NASA ASRS Text

Title: ACR X GPWS DSCNT BELOW MVA. SYS ERROR. EVASIVE ACTION TAKEN.

Narrative: ACR X TRAVELING FROM PIT TO CHO FOR ACR X, I WAS THE PNF OPERATING THE RADIOS. WE WERE WITH ZDC WHO WAS STARTING OUR DSCNT. HE FIRST TOOK US FROM OUR CRUISING ALT TO 8000 FT OR 9000 FT MSL. WE WERE THEN TOLD TO RPT THE ARPT IN SIGHT AND DSND TO 5000 FT MSL. ABOUT 3 OR 4 MINS, I ASKED ZDC IF THE ARPT WAS AT OUR 12 O'CLOCK AND 12 MI. HE TOLD US THAT IT WAS THE ARPT, SO WE CALLED IT IN SIGHT. HE THEN INSTRUCTED US TO DSND AND MAINTAIN 3100 FT MSL, BUT NOT TO GO BELOW THAT ALT UNTIL WE CONTACTED TWR. WE SWITCHED FREQS TO TWR AND STARTED OUR DSCNT TO 3100 FT MSL. WE CALLED TWR AND RPTED OUR POS AT ABOUT 4500 FT MSL. GPWS WENT OFF SAYING 'TOO LOW, PULL UP.' WE STOPPED OUR DSCNT AND LOOKED AT THE RADAR ALT WHICH READ 1200 FT. WE CALLED TWR AND ASKED THE ALT OF THE HIGHEST OBSTACLE. HE TOLD US THE HIGHEST POINT WAS 3600 FT MSL. WE REMAINED AT 4500 FT MSL UNTIL WE GOT CLOSER TO THE ARPT AND THEN LANDED USING THE VISUAL STOP INDICATORS.

Data retrieved from NASA's ASRS site as of July 2007 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.