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An air carrier aircraft moves when the parking brake is released during an anti-skid test at the gate. The chocks were not properly placed to prevent movement.
| Attributes | |
| ACN | 582383 |
| Time | |
| Date | 200305 |
| Day | Wed |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : phl.airport |
| State Reference | PA |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | MD-80 Super 80 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : parked ground : preflight |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : multi engine pilot : commercial |
| ASRS Report | 582383 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | non adherence : company policies non adherence : published procedure |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other |
| Supplementary | |
| Problem Areas | Maintenance Human Performance Company Flight Crew Human Performance |
| Primary Problem | Maintenance Human Performance |
Narrative:
The event occurred during an origination preflight inspection at the gate. The first officer released the parking brake in order to perform the anti-skid test. As the brakes were released the aircraft rolled abruptly backward about 6-8 inches before the brakes could be reapplied. Earlier, during the exterior safety inspection, it was observed that gear chocks were installed forward and aft of the left main landing gear. On reinspection of the left main landing gear it was apparent that the aft chock had not been placed immediately behind, in contact with, the gear. This incident, while uneventful, could have caused aircraft damage or bodily injury to ground crew. The lesson learned by the first officer is to ensure the gear is 'firmly' chocked. This lesson was lost on the ground crew who felt the parking brakes should never be released at the gate and seemed to doubt that the DC9 operating manual actually calls for the parking brakes to be released during the anti-skid test, (on a chocked aircraft.) callback conversation with reporter revealed the following information: the company manual covering chock placement requires them to be placed immediately behind the wheel. The procedure for testing the anti-skid requires that the parking brake be released to complete the check, but the brakes may be kept set to prevent movement of the aircraft if chocks are not installed.
Original NASA ASRS Text
Title: AN ACR ACFT MOVES WHEN THE PARKING BRAKE IS RELEASED DURING AN ANTI-SKID TEST AT THE GATE. THE CHOCKS WERE NOT PROPERLY PLACED TO PREVENT MOVEMENT.
Narrative: THE EVENT OCCURRED DURING AN ORIGINATION PREFLT INSPECTION AT THE GATE. THE FO RELEASED THE PARKING BRAKE IN ORDER TO PERFORM THE ANTI-SKID TEST. AS THE BRAKES WERE RELEASED THE ACFT ROLLED ABRUPTLY BACKWARD ABOUT 6-8 INCHES BEFORE THE BRAKES COULD BE REAPPLIED. EARLIER, DURING THE EXTERIOR SAFETY INSPECTION, IT WAS OBSERVED THAT GEAR CHOCKS WERE INSTALLED FORWARD AND AFT OF THE L MAIN LNDG GEAR. ON REINSPECTION OF THE L MAIN LNDG GEAR IT WAS APPARENT THAT THE AFT CHOCK HAD NOT BEEN PLACED IMMEDIATELY BEHIND, IN CONTACT WITH, THE GEAR. THIS INCIDENT, WHILE UNEVENTFUL, COULD HAVE CAUSED ACFT DAMAGE OR BODILY INJURY TO GND CREW. THE LESSON LEARNED BY THE FO IS TO ENSURE THE GEAR IS 'FIRMLY' CHOCKED. THIS LESSON WAS LOST ON THE GND CREW WHO FELT THE PARKING BRAKES SHOULD NEVER BE RELEASED AT THE GATE AND SEEMED TO DOUBT THAT THE DC9 OPERATING MANUAL ACTUALLY CALLS FOR THE PARKING BRAKES TO BE RELEASED DURING THE ANTI-SKID TEST, (ON A CHOCKED ACFT.) CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE COMPANY MANUAL COVERING CHOCK PLACEMENT REQUIRES THEM TO BE PLACED IMMEDIATELY BEHIND THE WHEEL. THE PROC FOR TESTING THE ANTI-SKID REQUIRES THAT THE PARKING BRAKE BE RELEASED TO COMPLETE THE CHK, BUT THE BRAKES MAY BE KEPT SET TO PREVENT MOVEMENT OF THE ACFT IF CHOCKS ARE NOT INSTALLED.
Data retrieved from NASA's ASRS site as of July 2007 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.