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A B747 parking break did not fully engage after parking at the gate and as the engines were shut down; it rolled forward striking the jetway.
| Attributes | |
| ACN | 1082940 |
| Time | |
| Date | 201304 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZZ.Airport |
| State Reference | FO |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | B747 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Parking Brake |
| Person 1 | |
| Function | Pilot Not Flying First Officer |
| Experience | Flight Crew Last 90 Days 140 Flight Crew Total 10025 Flight Crew Type 16 |
| Person 2 | |
| Function | Pilot Flying Captain |
| Experience | Flight Crew Last 90 Days 250 Flight Crew Total 35000 Flight Crew Type 8500 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Ground Event / Encounter Loss Of Aircraft Control |
Narrative:
Our approach; landing and taxi were all normal. After being directed to stop using the self-parking system at the gate; I observed the captain set the parking break. I watched as he took his hand away to make certain the parking brake handle remained up. I then observed out the right window that there was no aircraft movement indicated. We then proceeded with the remaining 'after parking flows' which are required prior to reading the parking checklist of which there are several items to include engine shutdown. As I was nearly finished with my items; the captain indicated that it appeared that we were moving as he simultaneously applied the brakes. This happened at the same moment the left wing came in contact with the jet bridge. The captain re-engaged the parking brake until a tug was able to push the aircraft back to the original spot. It was actually very difficult to tell we had impacted the bridge due to the slow movement of the aircraft and the fact that the brakes were applied at the same moment. There were no injuries to crew; passengers or ground personnel and the passengers were eventually deplaned via stairs at door 1R. During our delay after the event; the captain and I tried to make sense of what had happened and could not understand how the brakes could have been disengaged after being verified set. The only thing I can deduce is that the parking brake did disengage and until the engines were shut down; not more than a few seconds after the setting of the parking break; they provided enough thrust to give the aircraft forward momentum. During my 'after parking flows;' I did not observe any aircraft movement. Some possibly useful information could be derived from our pushback from the gate at the departure airport; the flight's origin. After pushback from the gate; the captain set the brakes and both he and I observed the handle not stay up but release as his hand was removed. He immediately reapplied the parking brake and they held normally with proper indications. This did not seem at all abnormal as I know a certain amount of initial pedal pressure is required for the parking brake to engage. The captain concurred with this analysis during our 'post event' discussions.
Original NASA ASRS Text
Title: A B747 parking break did not fully engage after parking at the gate and as the engines were shut down; it rolled forward striking the jetway.
Narrative: Our approach; landing and taxi were all normal. After being directed to stop using the Self-Parking System at the gate; I observed the Captain set the parking break. I watched as he took his hand away to make certain the parking brake handle remained up. I then observed out the right window that there was no aircraft movement indicated. We then proceeded with the remaining 'after parking flows' which are required prior to reading the Parking Checklist of which there are several items to include engine shutdown. As I was nearly finished with my items; the Captain indicated that it appeared that we were moving as he simultaneously applied the brakes. This happened at the same moment the left wing came in contact with the jet bridge. The Captain re-engaged the parking brake until a tug was able to push the aircraft back to the original spot. It was actually very difficult to tell we had impacted the bridge due to the slow movement of the aircraft and the fact that the brakes were applied at the same moment. There were no injuries to crew; passengers or ground personnel and the passengers were eventually deplaned via stairs at door 1R. During our delay after the event; the Captain and I tried to make sense of what had happened and could not understand how the brakes could have been disengaged after being verified set. The only thing I can deduce is that the parking brake did disengage and until the engines were shut down; not more than a few seconds after the setting of the parking break; they provided enough thrust to give the aircraft forward momentum. During my 'after parking flows;' I did not observe any aircraft movement. Some possibly useful information could be derived from our pushback from the gate at the departure airport; the flight's origin. After pushback from the gate; the Captain set the brakes and both he and I observed the handle not stay up but release as his hand was removed. He immediately reapplied the parking brake and they held normally with proper indications. This did not seem at all abnormal as I know a certain amount of initial pedal pressure is required for the parking brake to engage. The Captain concurred with this analysis during our 'post event' discussions.
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.