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|
Attributes | |
ACN | 838365 |
Time | |
Date | 200906 |
Local Time Of Day | 1201-1800 |
Place | |
Locale Reference | SLC.Airport |
State Reference | UT |
Environment | |
Flight Conditions | Mixed |
Light | Daylight |
Aircraft 1 | |
Make Model Name | B737-300 |
Flight Phase | Cruise |
Route In Use | STAR NORDK3 |
Component | |
Aircraft Component | Position Computing System |
Person 1 | |
Function | First Officer Pilot Flying |
Experience | Flight Crew Last 90 Days 254 |
Person 2 | |
Function | Captain Pilot Not Flying |
Experience | Flight Crew Last 90 Days 184 Flight Crew Type 7300 |
Events | |
Anomaly | Aircraft Equipment Problem Less Severe Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Clearance |
Narrative:
We were in cruise flight at FL340. We had been previously cleared direct to lho. Between 80 to 100 NM east of lho on the NORDK3 arrival into slc we were given a clearance to cross 60 NM east of lho at FL300. I entered 300 into the altitude window and then entered the restriction into the CDU; the captain checked it; and I hit enter. We both monitored the top of descent point as we proceeded. We saw the top of descent near 5 NM. Less than 30 seconds later the top of descent was gone and the CDU showed us between 3 and 4000 ft high. I saw there was less than 1 NM to the crossing point and immediately started descending. Before the captain had a chance to call ATC; they were calling us to see if we could make the restriction. The captain informed them that we had a navigation error and wouldn't make the restriction. He requested a vector; but the controller re-cleared us to descend to FL300. By this time we were past the crossing restriction point and still descending. The controller never indicated to us that there was a problem with missing the restriction and she never gave us a vector to compensate. As we continued the flight and had time to try to analyze what happened; the only thing we could figure out was the FMS must have been off by miles and when it updated our position; instantly changed to almost on top of our crossing restriction point.
Original NASA ASRS Text
Title: B737 flight crew reported a 9 mile map shift as they approached top of descent; causing them to miss a crossing restriction.
Narrative: We were in cruise flight at FL340. We had been previously cleared direct to LHO. Between 80 to 100 NM east of LHO on the NORDK3 arrival into SLC we were given a clearance to cross 60 NM east of LHO at FL300. I entered 300 into the altitude window and then entered the restriction into the CDU; the Captain checked it; and I hit enter. We both monitored the top of descent point as we proceeded. We saw the top of descent near 5 NM. Less than 30 seconds later the top of descent was gone and the CDU showed us between 3 and 4000 FT high. I saw there was less than 1 NM to the crossing point and immediately started descending. Before the Captain had a chance to call ATC; they were calling us to see if we could make the restriction. The Captain informed them that we had a navigation error and wouldn't make the restriction. He requested a vector; but the Controller re-cleared us to descend to FL300. By this time we were past the crossing restriction point and still descending. The Controller never indicated to us that there was a problem with missing the restriction and she never gave us a vector to compensate. As we continued the flight and had time to try to analyze what happened; the only thing we could figure out was the FMS must have been off by miles and when it updated our position; instantly changed to almost on top of our crossing restriction point.
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.