 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-700 captain noted that a series of aircraft autopilots level off between 150 ft and 400 ft early during descents in VNAV.
| Attributes | |
| ACN | 1107444 |
| Time | |
| Date | 201308 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Altitude Hold/Capture |
| Person 1 | |
| Function | Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Altitude Undershoot |
Narrative:
Had the aircraft level at 7;150 ft instead of 7;000 ft on descent. Aircraft was in VNAV. All altimeters were correct with no splits. I would think that this is just a glitch; but this is the third time I've had it happen in different aircraft over the last three weeks. It happens in VNAV mode only and errors have been between 140 ft and 400 ft every time. I don't know if there has been some sort of software update recently but again it has happened repeatedly with different first officers so I don't think that it is just me screwing up the FMC.
Original NASA ASRS Text
Title: A B737-700 Captain noted that a series of aircraft autopilots level off between 150 FT and 400 FT early during descents in VNAV.
Narrative: Had the aircraft level at 7;150 FT instead of 7;000 FT on descent. Aircraft was in VNAV. All altimeters were correct with no splits. I would think that this is just a glitch; but this is the third time I've had it happen in different aircraft over the last three weeks. It happens in VNAV mode only and errors have been between 140 FT and 400 FT every time. I don't know if there has been some sort of software update recently but again it has happened repeatedly with different first officers so I don't think that it is just me screwing up the FMC.
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.