Because they were flying in cavu daylight conditions and were familiar with the area the flight crew...

Narrative:

On initial climb; tower issued a climb to 2;000 ft MSL and a westerly heading. After initial check-in with TRACON; we maintained our initial instructions and leveled at 2;000 ft. We were then issued a turn to the south; and upon entering the turn in a timely manner; approximately 6 NM west of the airport; we received an aural GPWS warning 'terrain terrain; pull up'. At this point; we were in day VMC conditions and referenced the terrain page and continued the turn. There was only one warning cycle given and evasive action was not initiated due to fact that we were in day VMC; myself and the first officer were familiar with the area; no conflicting obstacles were noted on the terrain page nor visually; and the aural warning had stopped. I believe that the only obstacle in our vicinity which could have been calculated by the terrain system as a potential conflict was an 878 ft MSL tower. The flight continued without incident. Not knowing the minimum vectoring altitude in the area; it is difficult to tell the root cause of the event; whether we were taken too far west for our assigned altitude or if the GPWS system logic and parameters were responsible. The GPWS did test successfully before the flight as well as each flight since.

Original NASA ASRS Text

Title: Because they were flying in CAVU daylight conditions and were familiar with the area the flight crew of an unidentified Part 91 passenger flight aircraft chose not to respond to an apparently anomalous EGPWS 'Terrain' warning.

Narrative: On initial climb; Tower issued a climb to 2;000 FT MSL and a westerly heading. After initial check-in with TRACON; we maintained our initial instructions and leveled at 2;000 FT. We were then issued a turn to the south; and upon entering the turn in a timely manner; approximately 6 NM West of the airport; we received an aural GPWS warning 'terrain terrain; pull up'. At this point; we were in day VMC conditions and referenced the terrain page and continued the turn. There was only one warning cycle given and evasive action was not initiated due to fact that we were in day VMC; myself and the First Officer were familiar with the area; no conflicting obstacles were noted on the terrain page nor visually; and the aural warning had stopped. I believe that the only obstacle in our vicinity which could have been calculated by the terrain system as a potential conflict was an 878 FT MSL tower. The flight continued without incident. Not knowing the minimum vectoring altitude in the area; it is difficult to tell the root cause of the event; whether we were taken too far West for our assigned altitude or if the GPWS system logic and parameters were responsible. The GPWS did test successfully before the flight as well as each flight since.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1020942
Time
Date	201207
Local Time Of Day	1801-2400
Place
Locale Reference	OWD.Airport
State Reference	MA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	Climb Initial Climb
Flight Plan	IFR
Component
Aircraft Component	GPWS
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Inflight Event / Encounter CFTT / CFIT

Because they were flying in cavu daylight conditions and were familiar with the area the flight crew of an unidentified part 91 passenger flight aircraft chose not to respond to an apparently anomalous egpws 'terrain' warning.