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B737 pilot reports descending early on an ILS approach in VMC possibly due to fatigue after a very challenging day of flying.
| Attributes | |
| ACN | 988191 |
| Time | |
| Date | 201201 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Make Model Name | B737-800 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Initial Approach |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Autothrottle/Speed Control |
| Person 1 | |
| Function | Pilot Flying |
| Experience | Flight Crew Total 10000 |
| Events | |
| Anomaly | Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy |
Narrative:
[We received] extended vectors 20 mile final after a long day. Weather was scattered and we were VMC. [We were] cleared 3;000 to intercept final 'cleared ILS'. I noted 3;000 until the first intersection; and then non ILS habit pattern set 2;300 for the second intersection thinking we were already past the first intersection. The autothrottles were not maintaining commanded speed selected and I was over riding to maintain speed and troubleshooting reason for throttle problem. I started down with runway in sight and cleared to land. Once I realized we had not reached the first intersection yet I disconnected autopilot and corrected altitude and continued to configure for 30 flap and uneventful landing. Be aware of fatigue onset. We had a very challenging day at sna. Back course localizer 1L; wind shear. After engine start at sna ready for bleed off balanced field dept on 1L tower switched runway; new clearance; tps; FMS; etc; etc; etc. Even a generic ILS can bite you if you let your guard down. I will ensure better discussion of step down or altitude changes before initiating. We could have also just called the field and accepted a visual approach clearance. I will ensure not to confuse non ILS procedures with ILS.
Original NASA ASRS Text
Title: B737 pilot reports descending early on an ILS approach in VMC possibly due to fatigue after a very challenging day of flying.
Narrative: [We received] extended vectors 20 mile final after a long day. Weather was scattered and we were VMC. [We were] cleared 3;000 to intercept final 'cleared ILS'. I noted 3;000 until the first intersection; and then non ILS habit pattern set 2;300 for the second intersection thinking we were already past the first intersection. The autothrottles were not maintaining commanded speed selected and I was over riding to maintain speed and troubleshooting reason for throttle problem. I started down with runway in sight and cleared to land. Once I realized we had not reached the first intersection yet I disconnected autopilot and corrected altitude and continued to configure for 30 flap and uneventful landing. Be aware of fatigue onset. We had a very challenging day at SNA. BC LOC 1L; wind shear. After engine start at SNA ready for bleed off balanced field dept on 1L Tower switched runway; new clearance; TPS; FMS; etc; etc; etc. Even a generic ILS can bite you if you let your guard down. I will ensure better discussion of step down or altitude changes before initiating. We could have also just called the field and accepted a visual approach clearance. I will ensure not to confuse Non ILS procedures with ILS.
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.