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|
Attributes | |
ACN | 812834 |
Time | |
Date | 200811 |
Local Time Of Day | 0001 To 0600 |
Place | |
Locale Reference | airport : zzz.airport |
State Reference | US |
Altitude | agl single value : 0 |
Aircraft 1 | |
Operator | common carrier : air carrier |
Make Model Name | B737-300 |
Person 1 | |
Affiliation | company : air carrier |
Function | maintenance : technician |
Qualification | technician : powerplant technician : airframe |
Experience | maintenance technician : 8 |
ASRS Report | 812834 |
Person 2 | |
Affiliation | company : air carrier |
Function | maintenance : inspector |
Qualification | technician : powerplant technician : airframe technician : inspection authority |
Experience | maintenance technician : 4 |
ASRS Report | 812839 |
Events | |
Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure |
Independent Detector | other other : 2 |
Resolutory Action | none taken : detected after the fact |
Consequence | other |
Factors | |
Maintenance | contributing factor : manuals contributing factor : work cards contributing factor : lighting performance deficiency : non compliance with legal requirements performance deficiency : inspection performance deficiency : installation |
Supplementary | |
Problem Areas | Aircraft Chart Or Publication Maintenance Human Performance |
Primary Problem | Maintenance Human Performance |
Narrative:
Removed and replaced #4 l-hand flight deck eyebrow window and #5 flight deck window l-hand per engineering authority/authorized. Torqued #5 window same value as #4 window. 55-60 inch pounds when it is supposed to have been 20-25 inch pounds. Inspection had advised me and at the next routine overnight destination and the window was changed. No defects were noted with the previous window. Read maintenance manual and saw #4 and #5 together for removal and installation. Missed #5 window torque value and torqued to #4 window torque value; being together for removal and installation. Supplemental information from acn 812839: I had worked on aircraft examining the l-hand #4 and #5 cockpit windows. After determining the 2 windows were delaminated; removal and replacement was in progress. In the process; I inadvertently agreed and authorized both windows to be torqued to the same values at 55 inch pounds and complied with the remainder of the installation with no further incident. In reality; l-hand #5 window requires only 20-25 inch pounds (resulting in an over-torque realizing later). As I was working days on another aircraft that morning (6-7 hours later); replacing l-hand #4 cockpit window; was when I discovered that a mistake had been made on my previous aircraft. I immediately notified my supervisor and he made arrangements to have the window evaluated and was promptly changed after landing. I should have been more detailed but somehow failed to detect it at the time; further jobs and work cards will be more cautiously examined under better lighting. Misread amm and perhaps lighting could have been better.
Original NASA ASRS Text
Title: DURING THE REMOVAL AND REPLACEMENT OF THE #4 AND #5 LEFT-HAND COCKPIT EYEBROW WINDOWS ON A B737-300; AN INSPECTOR INADVERTENTLY AGREED AND AUTHORIZED A MECHANIC TO TORQUE BOTH WINDOWS TO THE #4 WINDOW TORQUE VALUES.
Narrative: REMOVED AND REPLACED #4 L-HAND FLT DECK EYEBROW WINDOW AND #5 FLT DECK WINDOW L-HAND PER ENGINEERING AUTH. TORQUED #5 WINDOW SAME VALUE AS #4 WINDOW. 55-60 INCH LBS WHEN IT IS SUPPOSED TO HAVE BEEN 20-25 INCH LBS. INSPECTION HAD ADVISED ME AND AT THE NEXT ROUTINE OVERNIGHT DEST AND THE WINDOW WAS CHANGED. NO DEFECTS WERE NOTED WITH THE PREVIOUS WINDOW. READ MAINT MANUAL AND SAW #4 AND #5 TOGETHER FOR REMOVAL AND INSTALLATION. MISSED #5 WINDOW TORQUE VALUE AND TORQUED TO #4 WINDOW TORQUE VALUE; BEING TOGETHER FOR REMOVAL AND INSTALLATION. SUPPLEMENTAL INFO FROM ACN 812839: I HAD WORKED ON ACFT EXAMINING THE L-HAND #4 AND #5 COCKPIT WINDOWS. AFTER DETERMINING THE 2 WINDOWS WERE DELAMINATED; REMOVAL AND REPLACEMENT WAS IN PROGRESS. IN THE PROCESS; I INADVERTENTLY AGREED AND AUTHORIZED BOTH WINDOWS TO BE TORQUED TO THE SAME VALUES AT 55 INCH LBS AND COMPLIED WITH THE REMAINDER OF THE INSTALLATION WITH NO FURTHER INCIDENT. IN REALITY; L-HAND #5 WINDOW REQUIRES ONLY 20-25 INCH LBS (RESULTING IN AN OVER-TORQUE REALIZING LATER). AS I WAS WORKING DAYS ON ANOTHER ACFT THAT MORNING (6-7 HRS LATER); REPLACING L-HAND #4 COCKPIT WINDOW; WAS WHEN I DISCOVERED THAT A MISTAKE HAD BEEN MADE ON MY PREVIOUS ACFT. I IMMEDIATELY NOTIFIED MY SUPVR AND HE MADE ARRANGEMENTS TO HAVE THE WINDOW EVALUATED AND WAS PROMPTLY CHANGED AFTER LNDG. I SHOULD HAVE BEEN MORE DETAILED BUT SOMEHOW FAILED TO DETECT IT AT THE TIME; FURTHER JOBS AND WORK CARDS WILL BE MORE CAUTIOUSLY EXAMINED UNDER BETTER LIGHTING. MISREAD AMM AND PERHAPS LIGHTING COULD HAVE BEEN BETTER.
Data retrieved from NASA's ASRS site as of May 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.