Narrative:

While on right base leg to runway 28L at 3;000 ft. We were given a visual and accepted as airport was in sight. Airplane was at 170 KIAS and at flaps 3 with autopilot on. The vector put us on a heading to intercept final at 90 degree angle to final 28L and inside the FAF pittz which has a glide slope intercept altitude of 3;000 ft. The glide slope for 28L indicated we were high so I asked for gear down; managed speed; flaps full and final check as I recall. Then we set 2;000 ft in the altitude window and I selected open descent to start down and attempt to get on vertical profile while still correcting simultaneously to a 60 degree angle to final.we intercepted the glide slope and within 5-6 seconds of starting down we got a 'caution terrain;terrain' warning and immediately went to toga and disconnected autopilot and corrected situation and climbed back up to 3;000 MSL. We were 5 miles approximately north of the airport and I estimate we were at 2;500 ft MSL when we got the warning. We were not aligned with runway 28L when intercepting glide slope but well north of the runway so we had no vertical protection. I then hand flew the airplane towards 28L but we were too high to make a safe landing so we proceeded to line up up with 28L and executed a normal go around and received vectors from ATC to return for a ILS 28L and made a uneventful approach and landing.

Google
 

Original NASA ASRS Text

Title: A320 Captain flying visual approach to PIT got a GPWS terrain warning; and after adjusting altitude was too high to continue approach.

Narrative: While on right base leg to Runway 28L at 3;000 FT. we were given a visual and accepted as airport was in sight. Airplane was at 170 KIAS and at flaps 3 with autopilot on. The vector put us on a heading to intercept final at 90 degree angle to final 28L and inside the FAF PITTZ which has a glide slope intercept altitude of 3;000 FT. The glide slope for 28L indicated we were high so I asked for gear down; managed speed; flaps full and final check as I recall. Then we set 2;000 FT in the altitude window and I selected open descent to start down and attempt to get on vertical profile while still correcting simultaneously to a 60 degree angle to final.We intercepted the glide slope and within 5-6 seconds of starting down we got a 'caution terrain;terrain' warning and immediately went to TOGA and disconnected autopilot and corrected situation and climbed back up to 3;000 MSL. We were 5 miles approximately north of the airport and I estimate we were at 2;500 FT MSL when we got the warning. We were not aligned with Runway 28L when intercepting glide slope but well north of the runway so we had no vertical protection. I then hand flew the airplane towards 28L but we were too high to make a safe landing so we proceeded to line up up with 28L and executed a normal go around and received vectors from ATC to return for a ILS 28L and made a uneventful approach and landing.

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.