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An A319 captain reported that he missed an assigned descent crossing restriction after slowing his airspeed for turbulence. Descent path deviation detection was difficult because of fatigue; the pfd level off point is updated slowly and its symbology different from his previous aircraft.
| Attributes | |
| ACN | 925886 |
| Time | |
| Date | 201012 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | A319 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Route In Use | Direct |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | FMS/FMC |
| Person 1 | |
| Function | Pilot Flying Captain |
| Qualification | Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Engineer |
| Experience | Flight Crew Last 90 Days 200 Flight Crew Total 14000 Flight Crew Type 350 |
| Events | |
| Anomaly | Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Clearance Inflight Event / Encounter Weather / Turbulence |
Narrative:
We were on a direct routing. We were told to cross our next fix at FL240. I started the descent in 'managed descent' and the FMS showed that we were right on the path to make the restriction. As we descended through about FL280 we entered a cloud layer and started to get light and then moderated turbulence. I immediately slowed the aircraft to turbulent penetration airspeed (275 KIAS) while continuing the descent. I then realized; too late; that we were not going to make the restriction. We crossed at about FL250 (1;000 ft high) and were handed off to the next controller. There was no mention of our being too high or of a conflict of any kind. As far as CRM goes the first officer and I had flown together before and work well together. We were at the end of a 13 hour duty day. We are both fairly new on the aircraft. He went through training in march 2010 and I went through in may 2010. Speaking for myself; I have 20 years on boeing/mcdonnell douglas aircraft; and those FMS displays have a continuously updated 'green arc' that shows exactly where your aircraft will level at the selected altitude. The airbus display is different. It has a small blue arrow that shows the level off point; but is not updated as quickly. I think that was a contributing factor in my delay in realizing that I was too high; after having slowed down for the turbulence.
Original NASA ASRS Text
Title: An A319 Captain reported that he missed an assigned descent crossing restriction after slowing his airspeed for turbulence. Descent path deviation detection was difficult because of fatigue; the PFD Level Off point is updated slowly and its symbology different from his previous aircraft.
Narrative: We were on a direct routing. We were told to cross our next fix at FL240. I started the descent in 'managed descent' and the FMS showed that we were right on the path to make the restriction. As we descended through about FL280 we entered a cloud layer and started to get light and then moderated turbulence. I immediately slowed the aircraft to turbulent penetration airspeed (275 KIAS) while continuing the descent. I then realized; too late; that we were not going to make the restriction. We crossed at about FL250 (1;000 FT high) and were handed off to the next controller. There was no mention of our being too high or of a conflict of any kind. As far as CRM goes the First Officer and I had flown together before and work well together. We were at the end of a 13 hour duty day. We are both fairly new on the aircraft. He went through training in March 2010 and I went through in May 2010. Speaking for myself; I have 20 years on Boeing/McDonnell Douglas aircraft; and those FMS displays have a continuously updated 'green arc' that shows exactly where your aircraft will level at the selected altitude. The Airbus display is different. It has a small blue arrow that shows the level off point; but is not updated as quickly. I think that was a contributing factor in my delay in realizing that I was too high; after having slowed down for the turbulence.
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.