En route swf to hpn at 3000 MSL aircraft GPWS gave pull up.

Attributes
ACN	194991
Time
Date	199111
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : hpn
State Reference	NY
Altitude	msl bound lower : 3000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Dawn
Aircraft 1
Controlling Facilities	tracon : n90
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 5000 flight time type : 2500
ASRS Report	194991
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other
Situations
ATC Facility	procedure or policy : unspecified
Publication	Unspecified

Narrative:

We were repositioning our flight. In cruise flight at 3000 ft the radar altimeter came alive (it is on anytime below 2500 ft AGL) and was reading between 2000-2300 ft as we flew over a ridge near the 'valre' intersection. Shortly thereafter an audible 'terrain-terrain' warning was issued by the GPWS. This is very common in this area due to mountainous terrain and the low altitude at which ATC brings us across the ridges. However, this time the warnings were persistent (10-15 seconds) followed by a 'pull up-pull up' warning. We climbed from 3000 ft and notified ATC. He then cleared us to maintain 4000 and assigned us a new heading to fly. He thought we were responding to a TCASII RA and questioned us about it. We informed him it was a GPWS reaction.

Original NASA ASRS Text

Title: ENRTE SWF TO HPN AT 3000 MSL ACFT GPWS GAVE PULL UP.

Narrative: WE WERE REPOSITIONING OUR FLT. IN CRUISE FLT AT 3000 FT THE RADAR ALTIMETER CAME ALIVE (IT IS ON ANYTIME BELOW 2500 FT AGL) AND WAS READING BTWN 2000-2300 FT AS WE FLEW OVER A RIDGE NEAR THE 'VALRE' INTXN. SHORTLY THEREAFTER AN AUDIBLE 'TERRAIN-TERRAIN' WARNING WAS ISSUED BY THE GPWS. THIS IS VERY COMMON IN THIS AREA DUE TO MOUNTAINOUS TERRAIN AND THE LOW ALT AT WHICH ATC BRINGS US ACROSS THE RIDGES. HOWEVER, THIS TIME THE WARNINGS WERE PERSISTENT (10-15 SECONDS) FOLLOWED BY A 'PULL UP-PULL UP' WARNING. WE CLBED FROM 3000 FT AND NOTIFIED ATC. HE THEN CLRED US TO MAINTAIN 4000 AND ASSIGNED US A NEW HDG TO FLY. HE THOUGHT WE WERE RESPONDING TO A TCASII RA AND QUESTIONED US ABOUT IT. WE INFORMED HIM IT WAS A GPWS REACTION.

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.