Narrative:

Flight was cleared to descend via the EAGLE5 arrival to phx. Proceeding from tiniz to payso first officer had aircraft in profile mode and the payso restriction was FL280-FL240 and 270 KTS. 270/fl+240 were displayed in the FMS and nav display. The altitude window was set to 4;000 ft. Prognosis page showed that we were on a descent profile with near zero vdev for the altitude restriction. We noticed that the target speed dropped to 250 KTS in the descent and I altered the cost index in the FMS. We discussed whether or not the new ci would capture the speed; and when it was not making a change; first officer selected 270 in tac mode. The aircraft dumped the nose as we discussed the speed restriction and we felt that it was going after the speed. We were now about 7 miles short of payso and within the altitude restriction block. The aircraft continued to descend through FL240. First officer disconnected the autopilot and recovered the aircraft approximately 400 ft low; before returning to FL240 prior to payso. We re-automated and selected lvl chg for the next restriction of FL180 at eagul. Once the aircraft was in an established descent for that restriction; the first officer reselected profile to see if it would maintain the descent. My airspeed target line decreased to 250 KTS; and the first officer's target increased to 325 KTS. The vdev showed us more than 2;000 ft above profile. First officer returned to lvl chg and we manually input each altitude limit for the remaining restrictions. We made eagle at FL180 and homrr at 16;000/250 KTS. When we dialed in the next fix; vnnom at 11;000; we realized that we were high and first officer extended full speedbrakes to try to make the restriction. We crossed the fix descending at 11;500 ft. No comments were made by ATC and there was no other traffic on TCAS at 20 mile range. We then received a runway change from 26 to 25L and made an uneventful landing.better planning prior to the arrival would have had us better prepared for the unexpected variances in the autopilot. We should have disconnected the autopilot sooner to hand fly the arrival at the first indication of problems with the FMS. I should have directed the first officer to stay focused on flying while I monitored the descent; especially if we decided to continue using the autopilot at all. The 11;000 ft restriction for vnnom is nearly impossible to make if you cross homrr near 16;000 ft and only 4 miles away.

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Original NASA ASRS Text

Title: A300 flight crew experiences speed and altitude anomalies during the EAGUL5 RNAV arrival to PHX landing west. The altimeter was set to local when cleared to descend via; prior to FL180.

Narrative: Flight was cleared to descend via the EAGLE5 arrival to PHX. Proceeding from TINIZ to PAYSO First Officer had aircraft in Profile Mode and the PAYSO restriction was FL280-FL240 and 270 KTS. 270/FL+240 were displayed in the FMS and Nav Display. The Altitude window was set to 4;000 FT. Prognosis page showed that we were on a descent profile with near zero VDEV for the altitude restriction. We noticed that the target speed dropped to 250 KTS in the descent and I altered the Cost Index in the FMS. We discussed whether or not the new CI would capture the speed; and when it was not making a change; First Officer selected 270 in TAC Mode. The aircraft dumped the nose as we discussed the speed restriction and we felt that it was going after the speed. We were now about 7 miles short of PAYSO and within the altitude restriction block. The aircraft continued to descend through FL240. First Officer disconnected the autopilot and recovered the aircraft approximately 400 FT low; before returning to FL240 prior to PAYSO. We re-automated and selected LVL CHG for the next restriction of FL180 at EAGUL. Once the aircraft was in an established descent for that restriction; the First Officer reselected Profile to see if it would maintain the descent. My airspeed target line decreased to 250 KTS; and the First Officer's target increased to 325 KTS. The VDEV showed us more than 2;000 FT above profile. First Officer returned to LVL CHG and we manually input each altitude limit for the remaining restrictions. We made Eagle at FL180 and HOMRR at 16;000/250 KTS. When we dialed in the next fix; VNNOM at 11;000; we realized that we were high and First Officer extended full speedbrakes to try to make the restriction. We crossed the fix descending at 11;500 FT. No comments were made by ATC and there was no other traffic on TCAS at 20 mile range. We then received a runway change from 26 to 25L and made an uneventful landing.Better planning prior to the arrival would have had us better prepared for the unexpected variances in the autopilot. We should have disconnected the autopilot sooner to hand fly the arrival at the first indication of problems with the FMS. I should have directed the First Officer to stay focused on flying while I monitored the descent; especially if we decided to continue using the autopilot at all. The 11;000 FT restriction for VNNOM is nearly impossible to make if you cross HOMRR near 16;000 FT and only 4 miles away.

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.