Aircraft received a ground proximity warning system alert and climbed to a higher altitude.

Attributes
ACN	168881
Time
Date	199101
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : hmv airport : tri
State Reference	TN
Altitude	msl bound lower : 5400 msl bound upper : 7000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : tri
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival other enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 11000 flight time type : 100
ASRS Report	168881
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

Descending into tri for an ILS to runway 23. First officer requested direct mocca LOM request was granted. Cleared to descend to 5400'. In IMC conditions, ground proximity warning system gave us a 'terrain' warning. Initiated an immediate climb to 7000'. Advised controller of problem, and he said there was no conflict with other aircraft. Callback conversation with reporter revealed the following information. Reporter talked to the controller about this incident. The controller told him that he was an area of 5400' which was okay as far as MVA was concerned. Reporter could not determine why the ground warning system sounded. He initiated the climb just to be safe. No traffic conflict due to the climb.

Original NASA ASRS Text

Title: ACFT RECEIVED A GND PROX WARNING SYSTEM ALERT AND CLIMBED TO A HIGHER ALT.

Narrative: DSNDING INTO TRI FOR AN ILS TO RWY 23. F/O REQUESTED DIRECT MOCCA LOM REQUEST WAS GRANTED. CLRED TO DSND TO 5400'. IN IMC CONDITIONS, GND PROX WARNING SYS GAVE US A 'TERRAIN' WARNING. INITIATED AN IMMEDIATE CLB TO 7000'. ADVISED CTLR OF PROB, AND HE SAID THERE WAS NO CONFLICT WITH OTHER ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. RPTR TALKED TO THE CTLR ABOUT THIS INCIDENT. THE CTLR TOLD HIM THAT HE WAS AN AREA OF 5400' WHICH WAS OKAY AS FAR AS MVA WAS CONCERNED. RPTR COULD NOT DETERMINE WHY THE GND WARNING SYS SOUNDED. HE INITIATED THE CLB JUST TO BE SAFE. NO TFC CONFLICT DUE TO THE CLB.

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.