 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A taxiing A320 notes the loss of their 'green' system's hydraulic fluid through an ECAM message. The crew runs the checklist for that fluid loss prior to stopping the aircraft. The captain, forgetting that the main wheel braking is on that system, allows the first officer to turn off the hydraulic pump for that system prior to stopping the aircraft and before the parking brake is set. The aircraft gets a sudden stop when the auxiliary system kicks in.
| Attributes | |
| ACN | 411954 |
| Time | |
| Date | 199808 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : msp |
| State Reference | MN |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | A320 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | ground other : taxi |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | A320 |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : flight engineer pilot : cfi pilot : atp |
| Experience | flight time last 90 days : 100 flight time total : 13500 flight time type : 1500 |
| ASRS Report | 411954 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : critical non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | Pilot Deviation other |
Narrative:
During preflight, the first officer noticed hydraulic fluid on the nose strut and called maintenance. They inspected the area for leaks and we turned the nosewheel several times -- no leak found. Hydraulic quantity checked ok. Logbook was signed and we departed. After a 3 hour flight and normal landing, I taxied clear of the runway. At that point the ECAM displayed hydraulic G rsvr lo lvl -- indicating loss of 'green' hydraulic system fluid. We were now moving very slowly on the taxiway while we (first officer) complied with ECAM procedures, of turning off hydraulic pump for the green system. I was trying to bring aircraft to a stop, since nosewheel steering and 'normal' brakes are on green system. Brake pedal application was not effective. I was looking at the alternate brake pressure gauge and expected it to register some pressure, but it remained at zero (as is normal when alternate brakes are not active). After several brake pedal deflections alternate brakes suddenly activated, causing an abrupt stop. Fortunately, all passenger and flight attendants were still seated. No one was injured. We set the parking brake and called for a tug.
Original NASA ASRS Text
Title: A TAXIING A320 NOTES THE LOSS OF THEIR 'GREEN' SYS'S HYD FLUID THROUGH AN ECAM MESSAGE. THE CREW RUNS THE CHKLIST FOR THAT FLUID LOSS PRIOR TO STOPPING THE ACFT. THE CAPT, FORGETTING THAT THE MAIN WHEEL BRAKING IS ON THAT SYS, ALLOWS THE FO TO TURN OFF THE HYD PUMP FOR THAT SYS PRIOR TO STOPPING THE ACFT AND BEFORE THE PARKING BRAKE IS SET. THE ACFT GETS A SUDDEN STOP WHEN THE AUX SYS KICKS IN.
Narrative: DURING PREFLT, THE FO NOTICED HYD FLUID ON THE NOSE STRUT AND CALLED MAINT. THEY INSPECTED THE AREA FOR LEAKS AND WE TURNED THE NOSEWHEEL SEVERAL TIMES -- NO LEAK FOUND. HYD QUANTITY CHKED OK. LOGBOOK WAS SIGNED AND WE DEPARTED. AFTER A 3 HR FLT AND NORMAL LNDG, I TAXIED CLR OF THE RWY. AT THAT POINT THE ECAM DISPLAYED HYD G RSVR LO LVL -- INDICATING LOSS OF 'GREEN' HYD SYS FLUID. WE WERE NOW MOVING VERY SLOWLY ON THE TXWY WHILE WE (FO) COMPLIED WITH ECAM PROCS, OF TURNING OFF HYD PUMP FOR THE GREEN SYS. I WAS TRYING TO BRING ACFT TO A STOP, SINCE NOSEWHEEL STEERING AND 'NORMAL' BRAKES ARE ON GREEN SYS. BRAKE PEDAL APPLICATION WAS NOT EFFECTIVE. I WAS LOOKING AT THE ALTERNATE BRAKE PRESSURE GAUGE AND EXPECTED IT TO REGISTER SOME PRESSURE, BUT IT REMAINED AT ZERO (AS IS NORMAL WHEN ALTERNATE BRAKES ARE NOT ACTIVE). AFTER SEVERAL BRAKE PEDAL DEFLECTIONS ALTERNATE BRAKES SUDDENLY ACTIVATED, CAUSING AN ABRUPT STOP. FORTUNATELY, ALL PAX AND FLT ATTENDANTS WERE STILL SEATED. NO ONE WAS INJURED. WE SET THE PARKING BRAKE AND CALLED FOR A TUG.
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.