Narrative:

We were flying a B737-700 on the abc arrival to runway 27L. Weather was a broken layer at 9;000 ft and a scattered layer at about 1;500 ft. It was daytime but light was getting low. The captain was flying the airplane. The captain selected the ILS 27L into the FMS. On the legs page; the first waypoint to appear was anval. At about 25 DME we received a vector to 210 degrees. We were at 7;000 ft MSL. A minute later we received a vector to fly '250 degrees to intercept; cleared ILS 27L prm; maintain at or above 7;000 ft until yabba.' I read back the clearance and the captain acknowledged it all except for the 7;000 ft at yabba. The captain attempted to set up the autopilot/flight director to use the LNAV/VNAV function to intercept the localizer and GS. As the functions were engaged; the aircraft began a 30 degree bank angle turn back toward the localizer course to the left and near the old vector of 210 degrees. I was monitoring this occurrence and suggested he use heading select to return to the issued 250 degree heading. As this was happening; the vertical axis of the airplane fell out of my crosscheck. The airplane began a descent. The captain had put the GS intercept altitude into the autopilot MCP. The active waypoint in the FMS was anval and the aircraft was engaged in VNAV. Therefore; the aircraft left 7;000 ft; began about a 1;500 FPM descent to reach the altitude. At this point we were not established on the localizer and were at about 22 DME. The descent put us below 7;000 ft before the yabba intersection. We reached 5;500 ft and at this point ATC queried our intentions. The captain stopped the descent using the altitude hold function and we re-intercepted the localizer/GS using the autopilot's 'approach' mode. The remainder of the approach flown normally. Causes: the first link in the error chain was the selection of the approach from the FMS. All the approach waypoints will not load unless you enter a transition. The captain did not and so the yabba intersection did not appear. My failure was to not back up the captain using DME information from the localizer in order to correlate our position with the DME of the yabba intersection. Thereby reestablishing our positional awareness. My attention was diverted trying to help correct the lateral deviation while the vertical deviation occurred. Mitigating causes: the 737-700 we were flying has much new symbology on the primary flight display and can be very confusing to someone who has not been specifically trained on it. I have received the training; but the captain; who was flying; had not yet. When primary displays show unfamiliar information; it leads to fixation on those unfamiliar areas and inattention to even more important aspects of the approach. I suggested to the captain that while on vectors to an approach; use heading select mode followed by localizer mode on the autopilot when cleared the approach. The LNAV engagement mode often does unpredictable maneuvers that are not precise enough first officer the approach environment.

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Original NASA ASRS Text

Title: A B737-700 flight crew on approach to ATL deviated from track and altitude assignments; in part due to their lack of familiarity with Primary Flight Display symbology.

Narrative: We were flying a B737-700 on the ABC arrival to Runway 27L. Weather was a broken layer at 9;000 FT and a scattered layer at about 1;500 FT. It was daytime but light was getting low. The Captain was flying the airplane. The Captain selected the ILS 27L into the FMS. On the legs page; the first waypoint to appear was ANVAL. At about 25 DME we received a vector to 210 degrees. We were at 7;000 FT MSL. A minute later we received a vector to fly '250 degrees to intercept; cleared ILS 27L PRM; maintain at or above 7;000 FT until YABBA.' I read back the clearance and the Captain acknowledged it all except for the 7;000 FT at YABBA. The Captain attempted to set up the Autopilot/Flight Director to use the LNAV/VNAV function to intercept the LOC and GS. As the functions were engaged; the aircraft began a 30 degree bank angle turn back toward the LOC course to the left and near the old vector of 210 degrees. I was monitoring this occurrence and suggested he use Heading Select to return to the issued 250 degree heading. As this was happening; the vertical axis of the airplane fell out of my crosscheck. The airplane began a descent. The Captain had put the GS intercept altitude into the Autopilot MCP. The active waypoint in the FMS was ANVAL and the aircraft was engaged in VNAV. Therefore; the aircraft left 7;000 FT; began about a 1;500 FPM descent to reach the altitude. At this point we were not established on the LOC and were at about 22 DME. The descent put us below 7;000 FT before the YABBA Intersection. We reached 5;500 FT and at this point ATC queried our intentions. The Captain stopped the descent using the altitude hold function and we re-intercepted the LOC/GS using the autopilot's 'Approach' mode. The remainder of the approach flown normally. Causes: The first link in the error chain was the selection of the approach from the FMS. All the approach waypoints will not load unless you enter a transition. The Captain did not and so the YABBA Intersection did not appear. My failure was to not back up the Captain using DME information from the LOC in order to correlate our position with the DME of the YABBA Intersection. Thereby reestablishing our positional awareness. My attention was diverted trying to help correct the lateral deviation while the vertical deviation occurred. Mitigating causes: The 737-700 we were flying has much new symbology on the Primary Flight Display and can be very confusing to someone who has not been specifically trained on it. I have received the training; but the Captain; who was flying; had not yet. When primary displays show unfamiliar information; it leads to fixation on those unfamiliar areas and inattention to even more important aspects of the approach. I suggested to the Captain that while on vectors to an approach; use Heading Select mode followed by LOC Mode on the autopilot when cleared the approach. The LNAV Engagement mode often does unpredictable maneuvers that are not precise enough First Officer the approach environment.

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.