Captain found parking brake problem during taxi out causing an abrupt stop and minor injury to a fli...

Attributes
ACN	454472
Time
Date	199911
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : phl.airport
State Reference	PA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	other pilot : atp pilot : flight engineer pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 12000 flight time type : 3800
ASRS Report	454472
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 190 flight time total : 23000 flight time type : 1000
ASRS Report	454603
Events
Anomaly	aircraft equipment problem : less severe cabin event other
Independent Detector	other flight crewa other flight crewb other other : 3
Resolutory Action	none taken : detected after the fact other
Consequence	other
Supplementary
Problem Areas	Aircraft Cabin Crew Human Performance
Primary Problem	Aircraft

Narrative:

Phl, on taxi out to departure call spot. Taxi to departure call spot and called ground control. Set parking brake. Cleared for further taxi. Released brakes. Brake set light and EICAS message remained on. Upon second attempt to release brakes, aircraft stopped abruptly. Aircraft was apparently rolling although parking brake indicated it was engaged. Flight attendants reported that one of them lost her balance and hurt her back. Called on interphone and she reported that she was ok for the flight. Asked her to come to flight deck. She stated that she hurt her back but was ok to continue and then returned to cabin. After several mins passed and we continued the taxi for departure, a different flight attendant called cockpit and stated that the above referenced flight attendant was hurt and needed to get off. Advised ground control and company operations, returned to gate and deplaned her. On taxi in, set parking brake 4 other times. Could not get it to repeat the abnormality. I don't know if this will help, but this particular B757 is fitted with the older version brakes that are very touchy/grabby, and this one of those models more so than the rest. A little experimentation showed that the parking brake indications work off the parking brake handle position, not actual brake condition. This particular handle did not completely go to release, it stuck slightly above its full down position maybe 1 out of every 6 test releases. It looks like it is full down but it's not. So the brakes indicate engaged but are not.

Original NASA ASRS Text

Title: CAPT FOUND PARKING BRAKE PROB DURING TAXI OUT CAUSING AN ABRUPT STOP AND MINOR INJURY TO A FLT ATTENDANT. AFTER RETURNING TO THE GATE, THE FLT ATTENDANT WAS DEPLANED AND TAKEN OFF ASSIGNED DUTY.

Narrative: PHL, ON TAXI OUT TO DEP CALL SPOT. TAXI TO DEP CALL SPOT AND CALLED GND CTL. SET PARKING BRAKE. CLRED FOR FURTHER TAXI. RELEASED BRAKES. BRAKE SET LIGHT AND EICAS MESSAGE REMAINED ON. UPON SECOND ATTEMPT TO RELEASE BRAKES, ACFT STOPPED ABRUPTLY. ACFT WAS APPARENTLY ROLLING ALTHOUGH PARKING BRAKE INDICATED IT WAS ENGAGED. FLT ATTENDANTS RPTED THAT ONE OF THEM LOST HER BAL AND HURT HER BACK. CALLED ON INTERPHONE AND SHE RPTED THAT SHE WAS OK FOR THE FLT. ASKED HER TO COME TO FLT DECK. SHE STATED THAT SHE HURT HER BACK BUT WAS OK TO CONTINUE AND THEN RETURNED TO CABIN. AFTER SEVERAL MINS PASSED AND WE CONTINUED THE TAXI FOR DEP, A DIFFERENT FLT ATTENDANT CALLED COCKPIT AND STATED THAT THE ABOVE REFED FLT ATTENDANT WAS HURT AND NEEDED TO GET OFF. ADVISED GND CTL AND COMPANY OPS, RETURNED TO GATE AND DEPLANED HER. ON TAXI IN, SET PARKING BRAKE 4 OTHER TIMES. COULD NOT GET IT TO REPEAT THE ABNORMALITY. I DON'T KNOW IF THIS WILL HELP, BUT THIS PARTICULAR B757 IS FITTED WITH THE OLDER VERSION BRAKES THAT ARE VERY TOUCHY/GRABBY, AND THIS ONE OF THOSE MODELS MORE SO THAN THE REST. A LITTLE EXPERIMENTATION SHOWED THAT THE PARKING BRAKE INDICATIONS WORK OFF THE PARKING BRAKE HANDLE POS, NOT ACTUAL BRAKE CONDITION. THIS PARTICULAR HANDLE DID NOT COMPLETELY GO TO RELEASE, IT STUCK SLIGHTLY ABOVE ITS FULL DOWN POS MAYBE 1 OUT OF EVERY 6 TEST RELEASES. IT LOOKS LIKE IT IS FULL DOWN BUT IT'S NOT. SO THE BRAKES INDICATE ENGAGED BUT ARE NOT.

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.

Captain found parking brake problem during taxi out causing an abrupt stop and minor injury to a flight attendant. After returning to the gate, the flight attendant was deplaned and taken off assigned duty.