Narrative:

We were on the expressway visual to rwy 31 at lga. The arrival and approach were well briefed. We descended out of 2500 ft and proceeded down the expressway. As we approached the expected turn point (the highway configuration); I noticed that we were low for our position. I felt that if we turned at the proper point without further descent; we would be fine. I commented to the pilot flying that we were low for our position. I also noted the buildings past the turn point and thought that if there was any delay in the turn; they would be a factor at our altitude. At the turn point the pilot flying continued ahead with a slight descent. I immediately called for a turn and climb. The pilot flying reacted immediately to my call. During this flight path change we received a 'pull up' warning. I believe there was just one 'pull up' aural warning before it stopped. It was a 'bang bang' type situation; i.e.; 'we need to climb/turn;' power up/turn; 'pull up; pull up' stops. We quickly established a proper flight path and glide path and landed uneventfully. Nothing was said until we were at the gate. We discussed in detail what had happened and why. The pilot flying talked about fixation on things other than his altitude. The progress page vertical speed and height below glidepath page was one of the distractions. We also talked about the requirement to execute the terrain avoidance maneuver. Neither one of us was 100% sure of the mandatory requirement during day VFR until we pulled out the fom. We both now are very aware of the requirement. We also discussed what it would have been like to do this in new york airspace. I stressed the importance of proper altitude control during our visual approaches and in traffic patterns. We both felt our lack of familiarity with lga in general and the 31 visual in particular was a factor.

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Original NASA ASRS Text

Title: An Air Carrier Flight Crew got a terrain warning on the Expressway Visual to LGA Runway 31.

Narrative: We were on the EXPRESSWAY Visual to Rwy 31 at LGA. The arrival and approach were well briefed. We descended out of 2500 ft and proceeded down the EXPRESSWAY. As we approached the expected turn point (the highway configuration); I noticed that we were low for our position. I felt that if we turned at the proper point without further descent; we would be fine. I commented to the Pilot Flying that we were low for our position. I also noted the buildings past the turn point and thought that if there was any delay in the turn; they would be a factor at our altitude. At the turn point the Pilot Flying continued ahead with a slight descent. I immediately called for a turn and climb. The Pilot Flying reacted immediately to my call. During this flight path change we received a 'pull up' warning. I believe there was just one 'pull up' aural warning before it stopped. It was a 'bang bang' type situation; I.E.; 'We need to climb/turn;' power up/turn; 'pull up; pull up' stops. We quickly established a proper flight path and glide path and landed uneventfully. Nothing was said until we were at the gate. We discussed in detail what had happened and why. The Pilot Flying talked about fixation on things other than his altitude. The Progress page vertical speed and height below glidepath page was one of the distractions. We also talked about the requirement to execute the terrain avoidance maneuver. Neither one of us was 100% sure of the mandatory requirement during day VFR until we pulled out the FOM. We both now are very aware of the requirement. We also discussed what it would have been like to do this in New York airspace. I stressed the importance of proper altitude control during our visual approaches and in traffic patterns. We both felt our lack of familiarity with LGA in general and the 31 visual in particular was a factor.

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.