A300
Flight Crew Air Transport Pilot (ATP)
Distraction; Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Flight Crew Returned To Clearance; General Maintenance Action
Aircraft; Human Factors
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.
We were assigned the EAGUL5 RNAV arrival; and were proceeding from TINIZ to PAYSO; the aircraft was in Profile Mode; and the next crossing restriction was FL240-FL280/270 KTS at PAYSO. Since we had been cleared to descend via the EAGUL for a Runway 26 transition; we had set the altimeters to local. After passing TINIZ; en route to PAYSO; the aircraft target speed suddenly became 250 KTS; since the next speed restriction was 270 KTS; the pilot not flying altered the Cost Index. After a short discussion on whether this would get us the correct speed; I selected TAC mode speed of 270 KTS and confirmed that the target speed was 270 KTS. We were distracted by discussing why the airplane wanted 250 KTS; and whether the Cost Index change would set the correct speeds; when the aircraft dumped the nose at about 6-7 NM short of PAYSO; we assumed it was trying to capture 270 KTS. We were still discussing what the Profile Mode was seeing when the aircraft failed to level off and continued its steep descent below FL240. I disconnected the autopilot and recovered the aircraft at approximately FL236 and climbed back to FL240. We reset the altimeters to STD and continued to PAYSO; I then selected the next altitude restriction; FL180 at EAGUL; and selected profile. When profile captured; the pilot not flying's airspeed target bug went to 250 KTS; and mine went to 325 KTS! The aircraft began a gentle descent; but the VDEV now showed us 2;000 plus above profile! Since we had just passed PAYSO at FL240; we decided the aircraft Profile Mode was not seeing the correct altitude restrictions; I then verified each of the next way points and restrictions manually on the FP page; and all was correct. We made the EAGUL restriction at FL180 in the LVL CHG mode; and the HOMRR restrictions at 16;000/250 KTS. Unfortunately; while we were distracted by analyzing the problem; we lost track of the upcoming required descent profile. What we didn't realize was how steep a descent we needed to be at VNNOM below 11;000 at 250 KTS. At about 5 NM from VNNOM; at 15;000/250 KTS; we realized we would need a much steeper descent to make that restriction. I selected full speed brakes and accelerated to about 270 KTS in an effort to make it; but we were still about 500 FT high at VNNOM. No comments were made to or received from ATC; and there was no other traffic on the arrival or nearby on TCAS. The rest of the approach continued normally; and we were given a last minute clearance to land on 25L instead of 26. We wrote up the discrepancy in the logbook; that the aircraft descended below an altitude restriction in the Profile mode; and the airspeed target bug differences immediately afterwards. More attention to detail! The Profile Mode seems to have difficulties in OPD's; and we noticed some irregularities. I should have been more attentive to the actual flight path; instead of trying to analyze and understand what Profile was seeing.
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.