An A320 pilot declares emergency after the remaining brake steering control unit channel faulted. Th...

Attributes
ACN	737868
Time
Date	200705
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	737868
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : company policies non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : ecam indication
Resolutory Action	flight crew : declared emergency
Consequence	other
Factors
Maintenance	performance deficiency : non compliance with legal requirements performance deficiency : repair performance deficiency : fault isolation
Supplementary
Problem Areas	Company Maintenance Human Performance Aircraft
Primary Problem	Company

Narrative:

One bscu channel was on MEL. When extending the gear for landing the second channel faulted with associated warnings. Mechanic told us afterward at the gate that the aircraft had ten of these boxes bscu in the past few months. Aircraft warnings declared emergency; contacted operations and maintenance control; followed procedures; landed without event. Find out why this aircraft is having so many problems with the bscu units. Callback conversation with reporter revealed the following information: reporter stated that nose steering was not available after the brake steering control unit (bscu) remaining channel two had faulted with associated warnings coming up. The bscu channel one was previously deferred per MEL. No other problems until he extended the landing gear and then the channel two failed. Reporter also stated they did a go-around to verify aircraft's status after declaring an emergency. The steering loss and the warnings were the same as when the nosewheel steering switch is moved to the off position. The green system pressure was good. Some of the previous bscu write-ups had been for the channel one faults.

Original NASA ASRS Text

Title: AN A320 PILOT DECLARES EMERGENCY AFTER THE REMAINING BRAKE STEERING CONTROL UNIT CHANNEL FAULTED. THE BSCU UNIT HAD ALREADY BEEN REPLACED 10 DIFFERENT TIMES.

Narrative: ONE BSCU CHANNEL WAS ON MEL. WHEN EXTENDING THE GEAR FOR LNDG THE SECOND CHANNEL FAULTED WITH ASSOCIATED WARNINGS. MECH TOLD US AFTERWARD AT THE GATE THAT THE ACFT HAD TEN OF THESE BOXES BSCU IN THE PAST FEW MONTHS. ACFT WARNINGS DECLARED EMER; CONTACTED OPS AND MAINT CTL; FOLLOWED PROCS; LANDED WITHOUT EVENT. FIND OUT WHY THIS ACFT IS HAVING SO MANY PROBS WITH THE BSCU UNITS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT NOSE STEERING WAS NOT AVAILABLE AFTER THE BRAKE STEERING CONTROL UNIT (BSCU) REMAINING CHANNEL TWO HAD FAULTED WITH ASSOCIATED WARNINGS COMING UP. THE BSCU CHANNEL ONE WAS PREVIOUSLY DEFERRED PER MEL. NO OTHER PROBLEMS UNTIL HE EXTENDED THE LANDING GEAR AND THEN THE CHANNEL TWO FAILED. REPORTER ALSO STATED THEY DID A GO-AROUND TO VERIFY ACFT'S STATUS AFTER DECLARING AN EMERGENCY. THE STEERING LOSS AND THE WARNINGS WERE THE SAME AS WHEN THE NOSEWHEEL STEERING SWITCH IS MOVED TO THE OFF POSITION. THE GREEN SYSTEM PRESSURE WAS GOOD. SOME OF THE PREVIOUS BSCU WRITE-UPS HAD BEEN FOR THE CHANNEL ONE FAULTS.

Data retrieved from NASA's ASRS site as of January 2009 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.

An A320 pilot declares emergency after the remaining brake steering control unit channel faulted. The bscu unit had already been replaced 10 different times.