 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-300 FMS dropped LNAV and executed a wide turn off the slc delta arrival after being given jammn.
| Attributes | |
| ACN | 838472 |
| Time | |
| Date | 200906 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | SLC.Airport |
| State Reference | UT |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Route In Use | STAR DELTA |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | FMS/FMC |
| Person 1 | |
| Function | Captain Pilot Flying |
| Experience | Flight Crew Last 90 Days 218 |
| Person 2 | |
| Function | First Officer |
| Experience | Flight Crew Last 90 Days 235 Flight Crew Type 4350 |
| Events | |
| Anomaly | Deviation - Procedural Clearance Deviation - Track / Heading All Types |
Narrative:
As we were arriving on the delta arrival into slc we were given direct jammn cross at 17;000. As we were leveling off we were given; 'expect runway 17.' the PF (first officer) put runway 17 into the FMC and executed it very quickly. I expected a right turn to on course on the arrival as we approached the fix. However; as the aircraft was at 280 KTS it rolled into 30 degrees of bank and turned well past the heading for the arrival to about 045. I was asking; 'where are we going?' and verifying the FMC and telling the pilot flying we need to turn back to the left. He stated the LNAV had kicked off and the aircraft was turning back to the south. I did not know if it was trying to hold or return back to jammn. I again called for a turn to the north and to return to the arrival. ATC called and asked where we were going and to turn to 310 degrees. We did that and were already turning back through 010 degrees. We had started the turn and I was clearing our flight path and concerned about being too rough in the turn. We had already begun a correction. I feel that the FMC was changed and executed too quickly for the phase of flight (leveling off and turning at a fix); verify; verify; verify.
Original NASA ASRS Text
Title: A B737-300 FMS dropped LNAV and executed a wide turn off the SLC DELTA arrival after being given JAMMN.
Narrative: As we were arriving on the DELTA Arrival into SLC we were given direct JAMMN cross at 17;000. As we were leveling off we were given; 'Expect Runway 17.' The PF (First Officer) put Runway 17 into the FMC and executed it very quickly. I expected a right turn to on course on the arrival as we approached the fix. However; as the aircraft was at 280 KTS it rolled into 30 degrees of bank and turned well past the heading for the arrival to about 045. I was asking; 'Where are we going?' and verifying the FMC and telling the pilot flying we need to turn back to the left. He stated the LNAV had kicked off and the aircraft was turning back to the south. I did not know if it was trying to hold or return back to JAMMN. I again called for a turn to the north and to return to the arrival. ATC called and asked where we were going and to turn to 310 degrees. We did that and were already turning back through 010 degrees. We had started the turn and I was clearing our flight path and concerned about being too rough in the turn. We had already begun a correction. I feel that the FMC was changed and executed too quickly for the phase of flight (leveling off and turning at a fix); Verify; verify; verify.
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.