37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 462753 |
Time | |
Date | 200001 |
Day | Sun |
Local Time Of Day | 0001 To 0600 |
Place | |
Locale Reference | airport : zzz.airport |
State Reference | US |
Altitude | agl single value : 0 |
Environment | |
Light | Night |
Aircraft 1 | |
Controlling Facilities | tower : lax.tower |
Operator | common carrier : air carrier |
Make Model Name | B737-400 |
Operating Under FAR Part | Part 121 |
Flight Phase | ground : maintenance ground : parked |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | maintenance : technician |
Qualification | technician : powerplant technician : airframe |
Experience | maintenance technician : 20 |
ASRS Report | 462753 |
Person 2 | |
Affiliation | company : air carrier |
Function | oversight : supervisor |
Qualification | technician : airframe technician : powerplant |
Events | |
Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure |
Resolutory Action | none taken : unable |
Consequence | Other |
Factors | |
Maintenance | contributing factor : schedule pressure performance deficiency : installation performance deficiency : repair performance deficiency : inspection |
Supplementary | |
Problem Areas | Maintenance Human Performance Aircraft Company Chart Or Publication |
Primary Problem | Company |
Narrative:
I was told to change the horizontal jackscrew on aircraft xyz on jan/sun/00. The job was already started by other mechanics. The left cable was already installed on the drum of the jackscrew. I installed the right cable on the drum. After installation of the cable I could not achieve the required tension on the cable per the maintenance manual. I was told by my foreman and the inspection foreman to cut 1 inch off the cable. I did what I was told. I cut 1 inch off the cable and swedged a new end on. I informed my foreman that I was not comfortable cutting the cable. He signed off the work and the inspection foreman signed off the inspection block. I installed the cable on the drum and started the tension process. I did not finish because my shift ended. The tension was achieved on the next shift, by another mechanic. I am reporting this, because I don't feel comfortable with the long cable. I feel the cable run through the aircraft should have been inspected. The length of the cable should have been determined before cutting it. Callback conversation with reporter revealed the following information: the reporter stated when it was discovered the cable was 1 inch too long, the production supervisor and the quality control supervisor were advised. The reporter said the supervisors without thinking of all the causes of why the cable was longer than normal ordered the cable cut to fit. The reporter said the new cable was pulled through the pulleys and guides using the worn cable and should have been the same length. The reporter stated the cable was made up in the carrier's shop and may have been cut wrong, but the possibility exists the cable being pulled in may have missed a pulley or guide, accounting for the excess. The reporter said a complete pulley and guide inspection should have been accomplished to ensure a serviceable cable run.
Original NASA ASRS Text
Title: A B737-400 WHILE HAVING THE STABILIZER TRIM JACKSCREW ASSEMBLY REPLACED IT WAS DISCOVERED THE REPLACEMENT R CABLE LENGTH IN ERROR.
Narrative: I WAS TOLD TO CHANGE THE HORIZ JACKSCREW ON ACFT XYZ ON JAN/SUN/00. THE JOB WAS ALREADY STARTED BY OTHER MECHS. THE L CABLE WAS ALREADY INSTALLED ON THE DRUM OF THE JACKSCREW. I INSTALLED THE R CABLE ON THE DRUM. AFTER INSTALLATION OF THE CABLE I COULD NOT ACHIEVE THE REQUIRED TENSION ON THE CABLE PER THE MAINT MANUAL. I WAS TOLD BY MY FOREMAN AND THE INSPECTION FOREMAN TO CUT 1 INCH OFF THE CABLE. I DID WHAT I WAS TOLD. I CUT 1 INCH OFF THE CABLE AND SWEDGED A NEW END ON. I INFORMED MY FOREMAN THAT I WAS NOT COMFORTABLE CUTTING THE CABLE. HE SIGNED OFF THE WORK AND THE INSPECTION FOREMAN SIGNED OFF THE INSPECTION BLOCK. I INSTALLED THE CABLE ON THE DRUM AND STARTED THE TENSION PROCESS. I DID NOT FINISH BECAUSE MY SHIFT ENDED. THE TENSION WAS ACHIEVED ON THE NEXT SHIFT, BY ANOTHER MECH. I AM RPTING THIS, BECAUSE I DON'T FEEL COMFORTABLE WITH THE LONG CABLE. I FEEL THE CABLE RUN THROUGH THE ACFT SHOULD HAVE BEEN INSPECTED. THE LENGTH OF THE CABLE SHOULD HAVE BEEN DETERMINED BEFORE CUTTING IT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED WHEN IT WAS DISCOVERED THE CABLE WAS 1 INCH TOO LONG, THE PRODUCTION SUPVR AND THE QUALITY CTL SUPVR WERE ADVISED. THE RPTR SAID THE SUPVRS WITHOUT THINKING OF ALL THE CAUSES OF WHY THE CABLE WAS LONGER THAN NORMAL ORDERED THE CABLE CUT TO FIT. THE RPTR SAID THE NEW CABLE WAS PULLED THROUGH THE PULLEYS AND GUIDES USING THE WORN CABLE AND SHOULD HAVE BEEN THE SAME LENGTH. THE RPTR STATED THE CABLE WAS MADE UP IN THE CARRIER'S SHOP AND MAY HAVE BEEN CUT WRONG, BUT THE POSSIBILITY EXISTS THE CABLE BEING PULLED IN MAY HAVE MISSED A PULLEY OR GUIDE, ACCOUNTING FOR THE EXCESS. THE RPTR SAID A COMPLETE PULLEY AND GUIDE INSPECTION SHOULD HAVE BEEN ACCOMPLISHED TO ENSURE A SERVICEABLE CABLE RUN.
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.