Narrative:

On the last leg of a four leg day; which included delays and de-icing twice; we were flying a visual approach to runway 28R in boi. The captain had line selected the RNAV 28R approach to back up his visual approach and was hand flying. It was nighttime; with clear skies; a full moon and snow covered ground making it very bright out. Boi approach had cleared us to descend to 8;000 ft and then cleared us for the visual approach to runway 28R. We were offset to the north slightly more than usual which put us over the higher terrain. During his visual approach he triggered a 'terrain; terrain; pull up' GPWS alert. The captain initiated a climb recovery and we were able to subsequently resume the approach. The lowest altitude I saw was 1;800 ft RA; we were visual with the terrain the entire time and flying down the slope of the terrain towards the valley. I was surprised that we received a 'pull up' command rather than a 'caution; terrain' callout.

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Original NASA ASRS Text

Title: An A319 flight crew got a GPWS 'Terrain Terrain Pull Up' alert on a night visual approach to BOI. They were in compliance with ATC cleared altitudes.

Narrative: On the last leg of a four leg day; which included delays and de-icing twice; we were flying a visual approach to Runway 28R in BOI. The Captain had line selected the RNAV 28R approach to back up his visual approach and was hand flying. It was nighttime; with clear skies; a full moon and snow covered ground making it very bright out. BOI Approach had cleared us to descend to 8;000 FT and then cleared us for the visual approach to Runway 28R. We were offset to the north slightly more than usual which put us over the higher terrain. During his visual approach he triggered a 'terrain; terrain; pull up' GPWS alert. The Captain initiated a climb recovery and we were able to subsequently resume the approach. The lowest altitude I saw was 1;800 FT RA; we were visual with the terrain the entire time and flying down the slope of the terrain towards the valley. I was surprised that we received a 'pull up' command rather than a 'caution; terrain' callout.

Data retrieved from NASA's ASRS site as of April 2012 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.