GPWS on approach. - NASA ASRS

Attributes
ACN	324474
Time
Date	199512
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : btv
State Reference	VT
Altitude	msl bound lower : 1800 msl bound upper : 6000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : btv
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 100 flight time total : 3000 flight time type : 700
ASRS Report	324474
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

GPWS activation during VOR approach at btv. At 8 DME inbound to the btv VOR, in a slow descent from 2000 ft MSL to 1700 ft MSL, the GPWS activated at 1850 ft MSL 'terrain terrain' followed immediately by 'whoop whoop pull-up.' we initiated the escape maneuver, informed approach, and climbed to 6000 ft MSL. We re-evaluated our situation, updated the WX, and all asked to fly the ILS runway 15. The winds now allowed us to land. (7 KT tailwind.) the ILS was uneventful. Prior to and after GPWS activation, I had checked that all navaids were tuned properly. A further check with tower, confirmed that we were on the approach radial. The activation of the GPWS was very startling, because we were virtually in level flight on a published approach. The captain was upgrading a new captain at this time. He did an excellent job of regrouping, including all of us in our decision to proceed to the ILS.

Original NASA ASRS Text

Title: GPWS ON APCH.

Narrative: GPWS ACTIVATION DURING VOR APCH AT BTV. AT 8 DME INBOUND TO THE BTV VOR, IN A SLOW DSCNT FROM 2000 FT MSL TO 1700 FT MSL, THE GPWS ACTIVATED AT 1850 FT MSL 'TERRAIN TERRAIN' FOLLOWED IMMEDIATELY BY 'WHOOP WHOOP PULL-UP.' WE INITIATED THE ESCAPE MANEUVER, INFORMED APCH, AND CLBED TO 6000 FT MSL. WE RE-EVALUATED OUR SIT, UPDATED THE WX, AND ALL ASKED TO FLY THE ILS RWY 15. THE WINDS NOW ALLOWED US TO LAND. (7 KT TAILWIND.) THE ILS WAS UNEVENTFUL. PRIOR TO AND AFTER GPWS ACTIVATION, I HAD CHKED THAT ALL NAVAIDS WERE TUNED PROPERLY. A FURTHER CHK WITH TWR, CONFIRMED THAT WE WERE ON THE APCH RADIAL. THE ACTIVATION OF THE GPWS WAS VERY STARTLING, BECAUSE WE WERE VIRTUALLY IN LEVEL FLT ON A PUBLISHED APCH. THE CAPT WAS UPGRADING A NEW CAPT AT THIS TIME. HE DID AN EXCELLENT JOB OF REGROUPING, INCLUDING ALL OF US IN OUR DECISION TO PROCEED TO THE ILS.

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.